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The Ames test is often used as one of the initial screens for potential drugs to weed out possible carcinogens, and it is one of the eight tests required under the Pesticide Act (USA) and one of the six tests required under the Toxic Substances Control Act (USA). Limitations. "Salmonella typhimurium" is a prokaryote, therefore it is not a perfect model for humans. Rat liver S9 fraction is used to mimic the mammalian metabolic conditions so that the mutagenic potential of metabolites formed by a parent molecule in the hepatic system can be assessed; however, there are differences in metabolism between humans and rats that can affect the mutagenicity of the chemicals being tested. The test may therefore be improved by the use of human liver S9 fraction; its use was previously limited by its availability, but it is now available commercially and therefore may be more feasible. An adapted "in vitro" model has been made for eukaryotic cells, for example yeast. Mutagens identified in the Ames test need not necessarily be carcinogenic, and further tests are required for any potential carcinogen identified in the test. Drugs that contain the nitrate moiety sometimes come back positive for Ames when they are indeed safe. The nitrate compounds may generate nitric oxide, an important signal molecule that can give a false positive. Nitroglycerin is an example that gives a positive Ames yet is still used in treatment today. Nitrates in food however may be reduced by bacterial action to nitrites which are known to generate carcinogens by reacting with amines and amides. Long toxicology and outcome studies are needed with such compounds to disprove a positive Ames test.
Fluctuation method. The Ames test was initially developed using agar plates (the plate incorporation technique), as described above. Since that time, an alternative to performing the Ames test has been developed, which is known as the "fluctuation method". This technique is the same in concept as the agar-based method, with bacteria being added to a reaction mixture with a small amount of histidine, which allows the bacteria to grow and mutate, returning to synthesize their own histidine. By including a pH indicator, the frequency of mutation is counted in microplates as the number of wells which have changed color (caused by a drop in pH due to metabolic processes of reproducing bacteria). As with the traditional Ames test, the sample is compared to the natural background rate of reverse mutation in order to establish the genotoxicity of a substance. The fluctuation method is performed entirely in liquid culture and is scored by counting the number of wells that turn yellow from purple in 96-well or 384-well microplates.
In the 96-well plate method the frequency of mutation is counted as the number of wells out of 96 which have changed color. The plates are incubated for up to five days, with mutated (yellow) colonies being counted each day and compared to the background rate of reverse mutation using established tables of significance to determine the significant differences between the background rate of mutation and that for the tested samples. In the more scaled-down 384-well plate microfluctuation method the frequency of mutation is counted as the number of wells out of 48 which have changed color after 2 days of incubation. A test sample is assayed across 6 dose levels with concurrent zero-dose (background) and positive controls which all fit into one 384-well plate. The assay is performed in triplicates to provide statistical robustness. It uses the recommended OECD Guideline 471 tester strains (histidine auxotrophs and tryptophan auxotrophs). The fluctuation method is comparable to the traditional pour plate method in terms of sensitivity and accuracy, however, it does have a number of advantages: it needs less test sample, it has a simple colorimetric endpoint, counting the number of positive wells out of possible 96 or 48 wells is much less time-consuming than counting individual colonies on an agar plate. Several commercial kits are available. Most kits have consumable components in a ready-to-use state, including lyophilized bacteria, and tests can be performed using multichannel pipettes. The fluctuation method also allows for testing higher volumes of aqueous samples (up to 75% v/v), increasing the sensitivity and extending its application to low-level environmental mutagens.
ACE inhibitor Angiotensin-converting-enzyme inhibitors (ACE inhibitors) are a class of medication used primarily for the treatment of high blood pressure and heart failure. This class of medicine works by causing relaxation of blood vessels as well as a decrease in blood volume, which leads to lower blood pressure and decreased oxygen demand from the heart. ACE inhibitors inhibit the activity of angiotensin-converting enzyme, an important component of the renin–angiotensin system which converts angiotensin I to angiotensin II, and hydrolyses bradykinin. Therefore, ACE inhibitors decrease the formation of angiotensin II, a vasoconstrictor, and increase the level of bradykinin, a peptide vasodilator. This combination is synergistic in lowering blood pressure. As a result of inhibiting the ACE enzyme in the bradykinin system, the ACE inhibitor drugs allow for increased levels of bradykinin which would normally be degraded. Bradykinin produces prostaglandin. This mechanism can explain the two most common side effects seen with ACE Inhibitors: angioedema and cough.
Frequently prescribed ACE inhibitors include benazepril, zofenopril, perindopril, trandolapril, captopril, enalapril, lisinopril, and ramipril. Medical use. ACE inhibitors were initially approved for the treatment of hypertension and can be used alone or in combination with other anti-hypertensive medications. Later, they were found useful for other cardiovascular and kidney diseases including: In treating high blood pressure, ACE inhibitors are often the first drug choice, particularly when diabetes is present, but age can lead to different choices and it is common to need more than one drug to obtain the desired improvement. There are fixed-dose combination drugs, such as ACE inhibitor and thiazide combinations. ACE inhibitors have also been used in chronic kidney failure and kidney involvement in systemic sclerosis (hardening of tissues, as scleroderma renal crisis). In those with stable coronary artery disease, but no heart failure, benefits are similar to other usual treatments. In 2012, a meta-analysis published in the BMJ described the protective role of ACE inhibitors in reducing the risk of pneumonia when compared to angiotensin II receptor blocker (ARBs). The authors found a decreased risk in patients with previous stroke (54% risk reduction), with heart failure (37% risk reduction), and of Asian descent (43% risk reduction vs 54% risk reduction in non-Asian population). However, no reduced pneumonia-related mortality was observed.
Other. ACE inhibitors may also be used to help decrease excessive water consumption in people with schizophrenia resulting in psychogenic polydipsia. A double-blind, placebo-controlled trial showed that when used for this purpose, enalapril led to decreased consumption (determined by urine output and osmolality) in 60% of people; the same effect has been demonstrated in other ACE inhibitors. Additionally ACE-I are commonly used after renal transplant to manage post-transplant erythrocytosis, a condition characterised by a persistently high hematocrit greater than 51% which often develops 8–24 months after successful transplantation, as ACE-I have been shown to decrease erythropoietin production. Adverse effects. Common side effects include: low blood pressure, cough, hyperkalemia, headache, dizziness, fatigue, nausea, and kidney impairment. The main adverse effects of ACE inhibition can be understood from their pharmacological action. The other reported adverse effects are liver problems and effects on the fetus. Kidney problems may occur with all ACE inhibitors that directly follows from their mechanism of action. Patients starting on an ACE inhibitor usually have a modest reduction in glomerular filtration rate (GFR). However, the decrease may be significant in conditions of "pre-existing" decreased renal perfusions, such as renal artery stenosis, heart failure, polycystic kidney disease, or volume depletion. In these patients, the maintenance of GFR depends on angiotensin-II-dependent efferent vasomotor tone. Therefore, renal function should be closely monitored over the first few days after initiation of treatment with ACE inhibitor in patients with decreased renal perfusion. Generally, a moderate reduction in renal function (no greater than 30% rise in serum creatinine which stabilizes within 2-4 weeks) is considered acceptable as part of the therapeutic effect.
Reduced GFR is especially a problem if the patient is concomitantly taking an NSAID and a diuretic. When the three drugs are taken together, the risk of developing renal failure is significantly increased. High blood potassium is another possible complication of treatment with an ACE inhibitor due to its effect on aldosterone. Suppression of angiotensin II leads to a decrease in aldosterone levels. Since aldosterone is responsible for increasing the excretion of potassium, ACE inhibitors can cause retention of potassium. Some people, however, can continue to lose potassium while on an ACE inhibitor. Hyperkalemia may decrease the velocity of impulse conduction in the nerves and muscles, including cardiac tissues. This leads to cardiac dysfunction and neuromuscular consequences, such as muscle weakness, paresthesia, nausea, diarrhea, and others. Close monitoring of potassium levels is required in patients receiving treatment with ACE inhibitors who are at risk of hyperkalemia. Another possible adverse effect specific for ACE inhibitors, but not for other RAAS blockers, is an increase in bradykinin level.
A persistent dry cough is a relatively common adverse effect believed to be associated with the increases in bradykinin levels produced by ACE inhibitors, although the role of bradykinin in producing these symptoms has been disputed. Many cases of cough in people on ACE inhibitors may not be from the medication itself, however. People who experience this cough are often switched to angiotensin II receptor antagonists. Some (0.7%) develop angioedema due to increased bradykinin levels. A genetic predisposition may exist. A severe rare allergic reaction can affect the bowel wall and secondarily cause abdominal pain. Blood. Hematologic effects, such as neutropenia, agranulocytosis and other blood dyscrasias, have occurred during therapy with ACE inhibitors, especially in people with additional risk factors. Pregnancy. In pregnant women, ACE inhibitors taken during all the trimesters have been reported to cause congenital malformations, stillbirths, and neonatal deaths. Commonly reported fetal abnormalities include hypotension, renal dysplasia, anuria/oliguria, oligohydramnios, intrauterine growth retardation, pulmonary hypoplasia, patent ductus arteriosus, and incomplete ossification of the skull. Overall, about half of newborns exposed to ACE inhibitors are adversely affected, leading to birth defects.
ACE inhibitors are ADEC pregnancy category D and should be avoided in women who are likely to become pregnant. In the U.S., ACE inhibitors must be labeled with a boxed warning concerning the risk of birth defects when taken during the second and third trimester. Their use in the first trimester is also associated with a risk of major congenital malformations, particularly affecting the cardiovascular and central nervous systems. Overdose. Symptoms and Treatment: There are few reports of ACE inhibitor overdose in the literature. The most likely manifestations are hypotension, which may be severe, hyperkalemia, hyponatremia and renal impairment with metabolic acidosis. Treatment should be mainly symptomatic and supportive, with volume expansion using normal saline to correct hypotension and improve renal function, and gastric lavage followed by activated charcoal and a cathartic to prevent further absorption of the drug. Captopril, enalapril, lisinopril and perindopril are known to be removable by hemodialysis.
Contraindications and precautions. The ACE inhibitors are contraindicated in people with: ACE inhibitors should be used with caution in people with: A combination of ACE inhibitor with other drugs may increase effects of these drugs, but also the risk of adverse effects. The commonly reported adverse effects of drug combination with ACE inhibitor are acute renal failure, hypotension, and hyperkalemia. The drugs interacting with ACE inhibitor should be prescribed with caution. Special attention should be given to combinations of ACE inhibitor with other RAAS blockers, diuretics (especially potassium-sparing diuretics), NSAIDs, anticoagulants, cyclosporine, DPP-4 inhibitors, and potassium supplements. Potassium supplementation should be used with caution and under medical supervision owing to the hyperkalemic effect of ACE inhibitors. Concomitant use with cyclooxygenase inhibitors tends to decrease ACE inhibitor's hypotensive effect. Mechanism of action. ACE inhibitors reduce the activity of the renin–angiotensin–aldosterone system (RAAS) as the primary etiologic (causal) event in the development of hypertension in people with diabetes mellitus, as part of the insulin-resistance syndrome or as a manifestation of renal disease.
Renin–angiotensin–aldosterone system. The renin–angiotensin–aldosterone system is a major blood pressure regulating mechanism. Markers of electrolyte and water imbalance in the body such as hypotension, low distal tubule sodium concentration, decreased blood volume and high sympathetic tone trigger the release of the enzyme renin from the cells of juxtaglomerular apparatus in the kidney. Renin activates a circulating liver derived prohormone angiotensinogen by proteolytic cleavage of all but its first ten amino acid residues known as angiotensin I. ACE (angiotensin converting enzyme) then removes a further two residues, converting angiotensin I into angiotensin II. ACE is found in the pulmonary circulation and in the endothelium of many blood vessels. The system increases blood pressure by increasing the amount of salt and water the body retains, although angiotensin II is also a potent vasoconstrictor. Effects. ACE inhibitors block the conversion of angiotensin I (ATI) to angiotensin II (ATII). They thereby lower arteriolar resistance and increase venous capacity; decrease cardiac output, cardiac index, stroke work, and volume; lower resistance in blood vessels in the kidneys; and lead to increased natriuresis (excretion of sodium in the urine). Renin increases in concentration in the blood as a result of negative feedback of conversion of ATI to ATII. ATI increases for the same reason; ATII and aldosterone decrease. Bradykinin increases because of less inactivation by ACE.
Under normal conditions, angiotensin II has these effects: During the course of ACE inhibitor use, the production of ATII is decreased, which prevents aldosterone release from the adrenal cortex. This allows the kidney to excrete sodium ions along with obligate water, and retain potassium ions. This decreases blood volume, leading to decreased blood pressure. Epidemiological and clinical studies have shown ACE inhibitors reduce the progress of diabetic nephropathy independently from their blood pressure-lowering effect. This action of ACE inhibitors is used in the prevention of diabetic renal failure. ACE inhibitors have been shown to be effective for indications other than hypertension even in patients with normal blood pressure. The use of a maximum dose of ACE inhibitors in such patients (including for prevention of diabetic nephropathy, congestive heart failure, and prophylaxis of cardiovascular events) is justified, because it improves clinical outcomes independently of the blood pressure-lowering effect of ACE inhibitors. Such therapy, of course, requires careful and gradual titration of the dose to prevent the effects of rapidly decreasing blood pressure (dizziness, fainting, etc.).
ACE inhibitors have also been shown to cause a central enhancement of parasympathetic nervous system activity in healthy volunteers and patients with heart failure. This action may reduce the prevalence of malignant cardiac arrhythmias, and the reduction in sudden death reported in large clinical trials. ACE Inhibitors also reduce plasma norepinephrine levels, and its resulting vasoconstriction effects, in heart failure patients, thus breaking the vicious circles of sympathetic and renin angiotensin system activation, which sustains the downward spiral in cardiac function in congestive heart failure The ACE inhibitor enalapril has also been shown to reduce cardiac cachexia in patients with chronic heart failure. Cachexia is a poor prognostic sign in patients with chronic heart failure. ACE inhibitors are under early investigation for the treatment of frailty and muscle wasting (sarcopenia) in elderly patients without heart failure. Examples. Currently, there are 10 ACE inhibitors approved for use in the United States by the FDA: captopril (1981), enalapril (1985), lisinopril (1987), benazepril (1991), fosinopril (1991), quinapril (1991), ramipril (1991), perindopril (1993), moexipril (1995) and trandolapril (1996).
ACE inhibitors are easily identifiable by their common suffix, '-pril'. ACE inhibitors can be divided into three groups based on their molecular structure of the enzyme binding sites (sulfhydryl, phosphinyl, carboxyl) to the active center of ACE: Sulfhydryl-containing agents. These agents appear to show antioxidative properties but may be involved in adverse events such as skin eruptions. Dicarboxylate-containing agents. This is the largest group, including: Comparative information. All ACE inhibitors have similar antihypertensive efficacy when equivalent doses are administered. The main differences lie with captopril, the first ACE inhibitor. Captopril has a shorter duration of action and an increased incidence of adverse effects. It is also capable of passing through the blood–brain barrier. In a large clinical study, one of the agents in the ACE inhibitor class, ramipril (Altace), demonstrated an ability to reduce the mortality rates of patients with a myocardial infarction and to slow the subsequent development of heart failure. This finding was made after it was discovered that regular use of ramipril reduced mortality rates even in test subjects who did not have hypertension.
Some believe ramipril's additional benefits may be shared by some or all drugs in the ACE-inhibitor class. However, ramipril currently remains the only ACE inhibitor for which such effects are actually evidence-based. A meta-analysis confirmed that ACE inhibitors are effective and certainly the first-line choice in hypertension treatment. This meta-analysis was based on 20 trials and a cohort of 158,998 patients, of whom 91% were hypertensive. ACE inhibitors were used as the active treatment in seven trials (n=76,615) and angiotensin receptor blocker (ARB) in 13 trials (n=82,383). ACE inhibitors were associated with a statistically significant 10% mortality reduction: (HR 0.90; 95% CI, 0.84–0.97; P=0.004). In contrast, no significant mortality reduction was observed with ARB treatment (HR 0.99; 95% CI, 0.94–1.04; P=0.683). Analysis of mortality reduction by different ACE inhibitors showed that perindopril-based regimens are associated with a statistically significant 13% all-cause mortality reduction. Taking into account the broad spectrum of the hypertensive population, one might expect that an effective treatment with ACE inhibitors, in particular with perindopril, would result in an important gain of lives saved.
Equivalent doses in hypertension. The ACE inhibitors have different strengths with different starting dosages. Dosage should be adjusted according to the clinical response. Combination with angiotensin II receptor antagonists. ACE inhibitors possess many common characteristics with another class of cardiovascular drugs, angiotensin II receptor antagonists, which are often used when patients are intolerant of the adverse effects produced by ACE inhibitors. ACE inhibitors do not completely prevent the formation of angiotensin II, as blockage is dose-dependent, so angiotensin II receptor antagonists may be useful because they act to prevent the action of angiotensin II at the AT1 receptor, leaving AT2 receptor unblocked; the latter may have consequences needing further study. The combination therapy of angiotensin II receptor antagonists with ACE inhibitors may be superior to either agent alone. This combination may increase levels of bradykinin while blocking the generation of angiotensin II and its activity at the AT1 receptor. This 'dual blockade' may be more effective than using an ACE inhibitor alone, because angiotensin II can be generated via non-ACE-dependent pathways. Preliminary studies suggest this combination of pharmacologic agents may be advantageous in the treatment of essential hypertension, chronic heart failure, and nephropathy. However, the more recent ONTARGET study showed no benefit of combining the agents and more adverse events. While statistically significant results have been obtained for its role in treating hypertension, clinical significance may be lacking. There are warnings about the combination of ACE inhibitors with ARBs.
Patients with heart failure may benefit from the combination in terms of reducing morbidity and ventricular remodeling. The most compelling evidence for the treatment of nephropathy has been found: This combination therapy partially reversed the proteinuria and also exhibited a renoprotective effect in patients with diabetic nephropathy, and pediatric IgA nephropathy. History. Leonard T. Skeggs and his colleagues (including Norman Shumway) discovered ACE in plasma in 1956. It was also noted that those who worked in banana plantations in South-western Brazil collapsed after being bitten by a pit viper, leading to a search for a blood pressure lowering component in its venom. Brazilian scientist Sérgio Henrique Ferreira reported a bradykinin-potentiating factor (BPF) present in the venom of "Bothrops jararaca", a South American pit viper, in 1965. Ferreira then went to John Vane's laboratory as a postdoctoral fellow with his already-isolated BPF. The conversion of the inactive angiotensin I to the potent angiotensin II was thought to take place in the plasma. However, in 1967, Kevin K. F. Ng and John R. Vane showed plasma ACE is too slow to account for the conversion of angiotensin I to angiotensin II "in vivo". Subsequent investigation showed rapid conversion occurs during its passage through the pulmonary circulation.
Bradykinin is rapidly inactivated in the circulating blood, and it disappears completely in a single pass through the pulmonary circulation. Angiotensin I also disappears in the pulmonary circulation because of its conversion to angiotensin II. Furthermore, angiotensin II passes through the lungs without any loss. The inactivation of bradykinin and the conversion of angiotensin I to angiotensin II in the lungs was thought to be caused by the same enzyme. In 1970, Ng and Vane, using BPF provided by Ferreira, showed the conversion is inhibited during its passage through the pulmonary circulation. BPFs are members of a family of peptides whose potentiating action is linked to inhibition of bradykinin by ACE. Molecular analysis of BPF yielded a nonapeptide BPF teprotide (SQ 20,881), which showed the greatest ACE inhibition potency and hypotensive effect "in vivo". Teprotide had limited clinical value as a result of its peptide nature and lack of activity when given orally. In the early 1970s, knowledge of the structure-activity relationship required for inhibition of ACE was growing. David Cushman, Miguel Ondetti and colleagues used peptide analogues to study the structure of ACE, using carboxypeptidase A as a model. Their discoveries led to the development of captopril, the first orally-active ACE inhibitor, in 1975.
Captopril was approved by the United States Food and Drug Administration in 1981. The first nonsulfhydryl-containing ACE inhibitor, enalapril, was approved four years later. At least 8 other ACE inhibitors have since been marketed. In 1991, Japanese scientists created the first milk-based ACE inhibitor, in the form of a fermented milk drink, using specific cultures to liberate the tripeptide isoleucine-proline-proline (IPP) from the dairy protein. Valine-proline-proline (VPP) is also liberated in this process—another milk tripeptide with a very similar chemical structure to IPP. Together, these peptides are now often referred to as lactotripeptides. In 1996, the first human study confirmed the blood pressure-lowering effect of IPP in fermented milk. Although twice the amount of VPP is needed to achieve the same ACE-inhibiting activity as the originally discovered IPP, VPP also is assumed to add to the total blood pressure lowering effect. Since the first lactotripeptides discovery, more than 20 human clinical trials have been conducted in many different countries.
Antianginal An antianginal is a drug used in the treatment of "angina pectoris", a symptom of ischaemic heart disease. Myocardial ischemia arises from the dysfunction of coronary macrovascular or microvascular components, leading to a compromised supply of oxygen and nutrients to the myocardium. The underlying pathophysiological mechanisms encompass a range of factors, including atherosclerosis in epicardial coronary arteries, vasospasm in large or small vessels, and microvascular dysfunction—whose clinical significance is increasingly acknowledged. The diverse clinical presentations of myocardial ischemia collectively fall under the term chronic coronary syndromes. Addressing these conditions involves a multifaceted approach, where the most common antianginal medications alleviate symptoms by inducing coronary vasodilation and modifying the determinants of myocardial oxygen consumption, such as heart rate, myocardial wall stress, and ventricular contractility. Additionally, these medications can alter cardiac substrate metabolism to alleviate ischemia by enhancing the efficiency of myocardial oxygen utilization. While there is consensus on the prognostic importance of lifestyle interventions and preventive measures like aspirin and statin therapy, determining the optimal antianginal treatment for chronic coronary syndrome patients remains less defined.
The majority of individuals experiencing stable angina can effectively address their condition through lifestyle modifications, particularly by embracing smoking cessation and incorporating regular exercise into their routine. Alongside these lifestyle changes, the use of antianginal drugs is a common approach. However, findings from randomized controlled trials reveal that the efficacy of various antianginal drugs is comparable, with none demonstrating a significant reduction in mortality or the risk of myocardial infarction (MI). Despite this, prevailing guidelines lean towards recommending beta-blockers and calcium channel blockers as the preferred first-line treatment. The European Society of Cardiology (ESC) guidelines for managing stable coronary artery disease provide well-defined classes of recommendation with corresponding levels of evidence. In a parallel vein, the National Institute for Health and Care Excellence (NICE) guidelines for stable angina management consider cost-effectiveness in their recommendations, designating terms such as first-line and second-line therapy. Notably, both sets of guidelines advocate for the use of low-dose aspirin and statins as disease-modifying agents.
This article aims to critically examine and evaluate the pharmacological recommendations outlined in these guidelines for the management of patients with stable angina. By delving into the nuances of these recommendations, we seek to provide a comprehensive understanding of the rationale behind the suggested pharmacological interventions for stable angina, shedding light on their respective strengths and considerations in clinical practice. Political Considerations. The 2019 guidelines from the European Society of Cardiology (ESC) advocate for a personalized approach in which antianginal medications are tailored to an individual patient's comorbidities and hemodynamic profile. It's noteworthy that, although antianginal medications do not improve survival, their effectiveness in symptom reduction significantly depends on the underlying mechanism of angina. Key considerations in antianginal therapies involve enhancing coronary vascular oxygen supply to the ischemic myocardium, reducing heart rate, myocardial work, and oxygen consumption, as well as optimizing the energetic efficiency of cardiomyocytes. Despite current guidelines recommending β-blockers and calcium-channel blockers as first-line therapy, there is a lack of evidence demonstrating their superiority over second-line therapies.
In this comprehensive review, it is crucial to emphasize that, thus far, neither drugs nor interventions that reduce ischemia have been shown to prolong survival in patients with chronic coronary syndromes. Examples. Drugs used are nitrates, beta blockers, or calcium channel blockers. Nitrates. Nitrates cause vasodilation of the venous capacitance vessels by stimulating the endothelium-derived relaxing factor (EDRF). Used to relieve both exertional and vasospastic angina by allowing venous pooling, reducing the pressure in the ventricles and so reducing wall tension and oxygen requirements in, the heart. Short-acting nitrates are used to abort angina attacks that have occurred, while longer-acting nitrates are used in the prophylactic management of the condition. Agents include glyceryl trinitrate (GTN), pentaerythritol tetranitrate, isosorbide dinitrate and isosorbide mononitrate. Beta blockers. Beta blockers are used in the prophylaxis of exertional angina by reducing the myocardial oxygen demand below the level that would provoke an angina attack.
They are contraindicated in variant angina and can precipitate heart failure. They are also contraindicated in severe asthmatics due to bronchoconstriction, and should be used cautiously in diabetics as they can mask symptoms of hypoglycemia. Agents include either cardioselectives such as acebutolol or metoprolol, or non-cardioselectives such as oxprenolol or sotalol. Calcium channel blockers. Calcium ion (Ca++) antagonists (Calcium channel blockers) are used in the treatment of chronic stable angina, and most effectively in the treatment of variant angina (directly preventing coronary artery vasospasm). They are not used in the treatment of unstable angina . In vitro, they dilate the coronary and peripheral arteries and have negative inotropic and chronotropic effects - decreasing afterload, improving myocardial efficiency, reducing heart rate and improving coronary blood flow. "In vivo", the vasodilation and hypotension trigger the baroreceptor reflex. Therefore, the net effect is the interplay of direct and reflex actions. Examples include Class I agents ("e.g.", verapamil), Class II agents ("e.g.", amlodipine, nifedipine), or the Class III agent diltiazem. Nifedipine is more a potent vasodilator and more effective in angina. It is in the class of dihydropyridines and does not affect refractory period on SA node conduction.
Anatomical Therapeutic Chemical Classification System The Anatomical Therapeutic Chemical (ATC) Classification System is a drug classification system that classifies the active ingredients of drugs according to the organ or system on which they act and their therapeutic, pharmacological and chemical properties. Its purpose is an aid to monitor drug use and for research to improve quality medication use. It does not imply drug recommendation or efficacy. It is controlled by the World Health Organization Collaborating Centre for Drug Statistics Methodology (WHOCC), and was first published in 1976. Coding system. This pharmaceutical coding system divides drugs into different groups according to the organ or system on which they act, their therapeutic intent or nature, and the drug's chemical characteristics. Different brands share the same code if they have the same active substance and indications. Each bottom-level ATC code stands for a pharmaceutically used substance, or a combination of substances, in a single indication (or use). This means that one drug can have more than one code, for example acetylsalicylic acid (aspirin) has as a drug for local oral treatment, as a platelet inhibitor, and as an analgesic and antipyretic; as well as one code can represent more than one active ingredient, for example is the combination of perindopril with amlodipine, two active ingredients that have their own codes ( and respectively) when prescribed alone.
The ATC classification system is a strict hierarchy, meaning that each code necessarily has one and only one parent code, except for the 14 codes at the topmost level which have no parents. The codes are semantic identifiers, meaning they depict information by themselves beyond serving as identifiers (namely, the codes depict themselves the complete lineage of parenthood). As of 7 May 2020, there are 6,331 codes in ATC; the table below gives the count per level. History. The ATC system is based on the earlier Anatomical Classification System, which is intended as a tool for the pharmaceutical industry to classify pharmaceutical products (as opposed to their active ingredients). This system, confusingly also called ATC, was initiated in 1971 by the European Pharmaceutical Market Research Association (EphMRA) and is being maintained by the EphMRA and Intellus. Its codes are organised into four levels. The WHO's system, having five levels, is an extension and modification of the EphMRA's. It was first published in 1976.
Classification. In this system, drugs are classified into groups at five different levels: First level. The first level of the code indicates the anatomical main group and consists of one letter. There are 14 main groups: "Example": C Cardiovascular system Second level. The second level of the code indicates the therapeutic subgroup and consists of two digits. "Example": C03 Diuretics Third level. The third level of the code indicates the therapeutic/pharmacological subgroup and consists of one letter. "Example": C03C High-ceiling diuretics Fourth level. The fourth level of the code indicates the chemical/therapeutic/pharmacological subgroup and consists of one letter. "Example": C03CA Sulfonamides Fifth level. The fifth level of the code indicates the chemical substance and consists of two digits. "Example": C03CA01 furosemide Other ATC classification systems. ATCvet. The "Anatomical Therapeutic Chemical Classification System for veterinary medicinal products" (ATCvet) is used to classify veterinary drugs. ATCvet codes can be created by placing the letter Q in front of the ATC code of most human medications. For example, furosemide for veterinary use has the code QC03CA01.
Some codes are used exclusively for veterinary drugs, such as "QI Immunologicals", "QJ51 Antibacterials for intramammary use" or "QN05AX90 amperozide". Herbal ATC (HATC). The Herbal ATC system (HATC) is an ATC classification of herbal substances; it differs from the regular ATC system by using 4 digits instead of 2 at the 5th level group. The herbal classification is not adopted by WHO. The Uppsala Monitoring Centre is responsible for the Herbal ATC classification, and it is part of the WHODrug Global portfolio available by subscription. Defined daily dose. The ATC system also includes defined daily doses (DDDs) for many drugs. This is a measurement of drug consumption based on the usual daily dose for a given drug. According to the definition, "[t]he DDD is the assumed average maintenance dose per day for a drug used for its main indication in adults." Adaptations and updates. National issues of the ATC classification, such as the German "Anatomisch-therapeutisch-chemische Klassifikation mit Tagesdosen", may include additional codes and DDDs not present in the WHO version.
ATC follows guidelines in creating new codes for newly approved drugs. An application is submitted to WHO for ATC classification and DDD assignment. A preliminary or temporary code is assigned and published on the website and in the "WHO Drug Information" for comment or objection. New ATC/DDD codes are discussed at the semi-annual Working Group meeting. If accepted it becomes a final decision and published semi-annually on the website and "WHO Drug Information" and implemented in the annual print/on-line ACT/DDD Index on January 1. Changes to existing ATC/DDD follow a similar process to become temporary codes and if accepted become a final decision as ATC/DDD alterations. ATC and DDD alterations are only valid and implemented in the coming annual updates; the original codes must continue until the end of the year. An updated version of the complete on-line/print ATC index with DDDs is published annually on January 1.
Parallel ATA Parallel ATA (PATA), originally , also known as Integrated Drive Electronics (IDE), is a standard interface designed for IBM PC-compatible computers. It was first developed by Western Digital and Compaq in 1986 for compatible hard drives and CD or DVD drives. The connection is used for storage devices such as hard disk drives, floppy disk drives, optical disc drives, and tape drives in computers. The standard is maintained by the X3/INCITS committee. It uses the underlying (ATA) and Packet Interface (ATAPI) standards. The Parallel ATA standard is the result of a long history of incremental technical development, which began with the original AT Attachment interface, developed for use in early PC AT equipment. The ATA interface itself evolved in several stages from Western Digital's original Integrated Drive Electronics (IDE) interface. As a result, many near-synonyms for ATA/ATAPI and its previous incarnations are still in common informal use, in particular Extended IDE (EIDE) and Ultra ATA (UATA). After the introduction of SATA in 2003, the original ATA was renamed to Parallel ATA, or PATA for short.
Parallel ATA cables have a maximum allowable length of . Because of this limit, the technology normally appears as an internal computer storage interface. For many years, ATA provided the most common and the least expensive interface for this application. It has largely been replaced by SATA in newer systems. History and terminology. The standard was originally conceived as the "AT Bus Attachment", officially called "AT Attachment" and abbreviated "ATA" because its primary feature was a direct connection to the 16-bit ISA bus introduced with the IBM PC/AT. The original ATA specifications published by the standards committees use the name "AT Attachment". The "AT" in the IBM PC/AT referred to "Advanced Technology" so ATA has also been referred to as "Advanced Technology Attachment". When a newer Serial ATA (SATA) was introduced in 2003, the original ATA was renamed to Parallel ATA, or PATA for short. Physical ATA interfaces became a standard component in all PCs, initially on host bus adapters, sometimes on a sound card but ultimately as two physical interfaces embedded in a Southbridge chip on a motherboard. Called the "primary" and "secondary" ATA interfaces, they were assigned to base addresses 0x1F0 and 0x170 on ISA bus systems. They were replaced by SATA interfaces.
IDE and ATA-1. The first version of what is now called the ATA/ATAPI interface was developed by Western Digital under the name "Integrated Drive Electronics" (IDE). Together with Compaq (the initial customer), they worked with various disk drive manufacturers to develop and ship early products with the goal of remaining software compatible with the existing IBM PC hard drive interface. The first such drives appeared internally in Compaq PCs in 1986 and were first separately offered by Conner Peripherals as the CP342 in June 1987. The term "Integrated Drive Electronics" refers to the drive controller being integrated into the drive, as opposed to a separate controller situated at the other side of the connection cable to the drive. On an IBM PC compatible, CP/M machine, or similar, this was typically a card installed on a motherboard. The interface cards used to connect a parallel ATA drive to, for example, an ISA Slot, are not drive controllers: they are merely bridges between the host bus and the ATA interface. Since the original ATA interface is essentially just a 16-bit ISA bus, the bridge was especially simple in case of an ATA connector being located on an ISA interface card. The integrated controller presented the drive to the host computer as an array of 512-byte blocks with a relatively simple command interface. This relieved the mainboard and interface cards in the host computer of the chores of stepping the disk head arm, moving the head arm in and out, and so on, as had to be done with earlier ST-506 and ESDI hard drives. All of these low-level details of the mechanical operation of the drive were now handled by the controller on the drive itself. This also eliminated the need to design a single controller that could handle many different types of drives, since the controller could be unique for the drive. The host need only to ask for a particular sector, or block, to be read or written, and either accept the data from the drive or send the data to it.
The interface used by these drives was standardized in 1994 as ANSI standard X3.221-1994, "AT Attachment Interface for Disk Drives". After later versions of the standard were developed, this became known as "ATA-1". A short-lived, seldom-used implementation of ATA was created for the IBM XT and similar machines that used the 8-bit version of the ISA bus. It has been referred to as "XT-IDE", "XTA" or "XT Attachment". EIDE and ATA-2. In 1994, about the same time that the ATA-1 standard was adopted, Western Digital introduced drives under a newer name, Enhanced IDE (EIDE). These included most of the features of the forthcoming ATA-2 specification and several additional enhancements. Other manufacturers introduced their own variations of ATA-1 such as "Fast ATA" and "Fast ATA-2". The new version of the ANSI standard, "AT Attachment Interface with Extensions ATA-2" (X3.279-1996), was approved in 1996. It included most of the features of the manufacturer-specific variants. ATA-2 also was the first to note that devices other than hard drives could be attached to the interface:
ATAPI. ATA was originally designed for, and worked only with, hard disk drives and devices that could emulate them. The introduction of ATAPI (ATA Packet Interface) by a group called the Small Form Factor committee (SFF) allowed ATA to be used for a variety of other devices that require functions beyond those necessary for hard disk drives. For example, any removable media device needs a "media eject" command, and a way for the host to determine whether the media is present, and these were not provided in the ATA protocol. ATAPI is a protocol allowing the ATA interface to carry SCSI commands and responses; therefore, all ATAPI devices are actually "speaking SCSI" other than at the electrical interface. The SCSI commands and responses are embedded in "packets" (hence "ATA Packet Interface") for transmission on the ATA cable. This allows any device class for which a SCSI command set has been defined to be interfaced via ATA/ATAPI. ATAPI devices are also "speaking ATA", as the ATA physical interface and protocol are still being used to send the packets. On the other hand, ATA hard drives and solid state drives do not use ATAPI.
ATAPI devices include CD-ROM and DVD-ROM drives, tape drives, and large-capacity floppy drives such as the Zip drive and SuperDisk drive. Some early ATAPI devices were simply SCSI devices with an ATA/ATAPI to SCSI protocol converter added on. The SCSI commands and responses used by each class of ATAPI device (CD-ROM, tape, etc.) are described in other documents or specifications specific to those device classes and are not within ATA/ATAPI or the T13 committee's purview. One commonly used set is defined in the MMC SCSI command set. ATAPI was adopted as part of ATA in INCITS 317-1998, "AT Attachment with Packet Interface Extension (ATA/ATAPI-4)". UDMA and ATA-4. The ATA/ATAPI-4 standard also introduced several "Ultra DMA" transfer modes. These initially supported speeds from 16 to 33 MB/s. In later versions, faster Ultra DMA modes were added, requiring new 80-wire cables to reduce crosstalk. The latest versions of Parallel ATA support up to 133 MB/s. Ultra ATA. Ultra ATA, abbreviated UATA, is a designation that has been primarily used by Western Digital for different speed enhancements to the ATA/ATAPI standards. For example, in 2000 Western Digital published a document describing "Ultra ATA/100", which brought performance improvements for the then-current ATA/ATAPI-5 standard by improving maximum speed of the Parallel ATA interface from 66 to 100 MB/s. Most of Western Digital's changes, along with others, were included in the ATA/ATAPI-6 standard (2002).
x86 BIOS size limitations. Initially, the size of an ATA drive was stored in the system x86 BIOS using a type number (1 through 45) that predefined the C/H/S parameters and also often the landing zone, in which the drive heads are parked while not in use. Later, a "user definable" format called C/H/S or cylinders, heads, sectors was made available. These numbers were important for the earlier ST-506 interface, but were generally meaningless for ATA—the CHS parameters for later ATA large drives often specified impossibly high numbers of heads or sectors that did not actually define the internal physical layout of the drive at all. From the start, and up to ATA-2, every user had to specify explicitly how large every attached drive was. From ATA-2 on, an "identify drive" command was implemented that can be sent and which will return all drive parameters. Owing to a lack of foresight by motherboard manufacturers, the system BIOS was often hobbled by artificial C/H/S size limitations due to the manufacturer assuming certain values would never exceed a particular numerical maximum.
The first of these BIOS limits occurred when ATA drives reached sizes in excess of 504 MiB, because some motherboard BIOSes would not allow C/H/S values above 1024 cylinders, 16 heads, and 63 sectors. Multiplied by 512 bytes per sector, this totals bytes which, divided by bytes per MiB, equals 504 MiB (528 MB). The second of these BIOS limitations occurred at 1024 cylinders, 256 heads, and 63 sectors, and a problem in MS-DOS limited the number of heads to 255. This totals to bytes (8032.5 MiB), commonly referred to as the 8.4 gigabyte barrier. This is again a limit imposed by x86 BIOSes, and not a limit imposed by the ATA interface. It was eventually determined that these size limitations could be overridden with a small program loaded at startup from a hard drive's boot sector. Some hard drive manufacturers, such as Western Digital, started including these override utilities with large hard drives to help overcome these problems. However, if the computer was booted in some other manner without loading the special utility, the invalid BIOS settings would be used and the drive could either be inaccessible or appear to the operating system to be damaged.
Later, an extension to the x86 BIOS disk services called the "Enhanced Disk Drive" (EDD) was made available, which makes it possible to address drives as large as 264 sectors. Interface size limitations. The first drive interface used 22-bit addressing mode which resulted in a maximum drive capacity of two gigabytes. Later, the first formalized ATA specification used a 28-bit addressing mode through LBA28, allowing for the addressing of 228 () sectors (blocks) of 512 bytes each, resulting in a maximum capacity of 128 GiB (137 GB). ATA-6 introduced 48-bit addressing, increasing the limit to 128 PiB (144 PB). As a consequence, any ATA drive of capacity larger than about 137 GB must be an ATA-6 or later drive. Connecting such a drive to a host with an ATA-5 or earlier interface will limit the usable capacity to the maximum of the interface. Some operating systems, including Windows XP pre-SP1, and Windows 2000 pre-SP3, disable LBA48 by default, requiring the user to take extra steps to use the entire capacity of an ATA drive larger than about 137 gigabytes.
Older operating systems, such as Windows 98, do not support 48-bit LBA at all. However, members of the third-party group MSFN have modified the Windows 98 disk drivers to add unofficial support for 48-bit LBA to Windows 95 OSR2, Windows 98, Windows 98 SE and Windows ME. Some 16-bit and 32-bit operating systems supporting LBA48 may still not support disks larger than 2 TiB due to using 32-bit arithmetic only; a limitation also applying to many boot sectors. Primacy and obsolescence. Parallel ATA (then simply called ATA or IDE) became the primary storage device interface for PCs soon after its introduction. In some systems, a third and fourth motherboard interface was provided, allowing up to eight ATA devices to be attached to the motherboard. Often, these additional connectors were implemented by inexpensive RAID controllers. Soon after the introduction of Serial ATA (SATA) in 2003, use of Parallel ATA declined. Some PCs and laptops of the era have a SATA hard disk and an optical drive connected to PATA. As of 2007, some PC chipsets, for example the Intel ICH10, had removed support for PATA. Motherboard vendors still wishing to offer Parallel ATA with those chipsets must include an additional interface chip. In more recent computers, the Parallel ATA interface is rarely used even if present, as four or more Serial ATA connectors are usually provided on the motherboard and SATA devices of all types are common.
With Western Digital's withdrawal from the PATA market, hard disk drives with the PATA interface were no longer in production after December 2013 for other than specialty applications. Interface. Parallel ATA cables transfer data 16 bits at a time. The traditional cable uses 40-pin female insulation displacement connectors (IDC) attached to a 40- or 80-conductor ribbon cable. Each cable has two or three connectors, one of which plugs into a host adapter interfacing with the rest of the computer system. The remaining connector(s) plug into storage devices, most commonly hard disk drives or optical drives. Each connector has 39 physical pins arranged into two rows (2.54 mm, -inch pitch), with a gap or key at pin 20. Earlier connectors may not have that gap, with all 40 pins available. Thus, later cables with the gap filled in are incompatible with earlier connectors, although earlier cables are compatible with later connectors. Round parallel ATA cables (as opposed to ribbon cables) were eventually made available for 'case modders' for cosmetic reasons, as well as claims of improved computer cooling and were easier to handle; however, only ribbon cables are supported by the ATA specifications. 44-pin variant.
A 44-pin variant PATA connector is used for 2.5 inch drives inside laptops. The pins are closer together (2.0 mm pitch) and the connector is physically smaller than the 40-pin connector. The extra pins carry power. 80-conductor variant. ATA's cables have had 40 conductors for most of its history (44 conductors for the smaller form-factor version used for 2.5" drives—the extra four for power), but an 80-conductor version appeared with the introduction of the "UDMA/66" mode. All of the additional conductors in the new cable are grounds, interleaved with the signal conductors to reduce the effects of capacitive coupling between neighboring signal conductors, reducing crosstalk. Capacitive coupling is more of a problem at higher transfer rates, and this change was necessary to enable the 66 megabytes per second (MB/s) transfer rate of "UDMA4" to work reliably. The faster "UDMA5" and "UDMA6" modes also require 80-conductor cables. Though the number of conductors doubled, the number of connector pins and the pinout remain the same as 40-conductor cables, and the external appearance of the connectors is identical. Internally, the connectors are different; the connectors for the 80-conductor cable connect a larger number of ground conductors to the ground pins, while the connectors for the 40-conductor cable connect ground conductors to ground pins one-to-one. 80-conductor cables usually come with three differently colored connectors (blue, black, and gray for controller, master drive, and slave drive respectively) as opposed to uniformly colored 40-conductor cable's connectors (commonly all gray). The gray connector on 80-conductor cables has pin 28 CSEL not connected, making it the slave position for drives configured cable select.
Multiple devices on a cable. If two devices are attached to a single cable, one must be designated as "Device 0" (in the past, commonly designated "master") and the other as "Device 1" (in the past, commonly designated as "slave"). This distinction is necessary to allow both drives to share the cable without conflict. The "Device 0" drive is the drive that usually appears "first" to the computer's BIOS and/or operating system. In most personal computers the drives are often designated as "C:" for the "Device 0" and "D:" for the "Device 1" referring to one active primary partitions on each. The mode that a device must use is often set by a jumper setting on the device itself, which must be manually set to "Device 0" ("Master") or "Device 1" ("Slave"). If there is a single device on a cable, it should be configured as "Device 0". However, some certain era drives have a special setting called "Single" for this configuration (Western Digital, in particular). Also, depending on the hardware and software available, a "Single" drive on a cable will often work reliably even though configured as the "Device 1" drive (most often seen where an optical drive is the only device on the secondary ATA interface).
The words "primary" and "secondary" typically refers to the two IDE cables, which can have two drives each (primary master, primary slave, secondary master, secondary slave). There are many debates about how much a slow device can impact the performance of a faster device on the same cable. On early ATA host adapters, both devices' data transfers can be constrained to the speed of the slower device, if two devices of different speed capabilities are on the same cable. For all modern ATA host adapters, this is not true, as modern ATA host adapters support "independent device timing". This allows each device on the cable to transfer data at its own best speed. Even with earlier adapters without independent timing, this effect applies only to the data transfer phase of a read or write operation. This is caused by the omission of both overlapped and queued feature sets from most parallel ATA products. Only one device on a cable can perform a read or write operation at one time; therefore, a fast device on the same cable as a slow device under heavy use will find it has to wait for the slow device to complete its task first. However, most modern devices will report write operations as complete once the data is stored in their onboard cache memory, before the data is written to the (slow) magnetic storage. This allows commands to be sent to the other device on the cable, reducing the impact of the "one operation at a time" limit. The impact of this on a system's performance depends on the application. For example, when copying data from an optical drive to a hard drive (such as during software installation), this effect probably will not matter. Such jobs are necessarily limited by the speed of the optical drive no matter where it is. But if the hard drive in question is also expected to provide good throughput for other tasks at the same time, it probably should not be on the same cable as the optical drive.
Cable select. A drive mode called "cable select" was described as optional in ATA-1 and has come into fairly widespread use with ATA-5 and later. A drive set to "cable select" automatically configures itself as "Device 0" or "Device 1", according to its position on the cable. Cable select is controlled by pin 28. The host adapter grounds this pin; if a device sees that the pin is grounded, it becomes the "Device 0" (master) device; if it sees that pin 28 is open, the device becomes the "Device 1" (slave) device. This setting is usually chosen by a jumper setting on the drive called "cable select", usually marked "CS", which is separate from the "Device 0/1" setting. If two drives are configured as "Device 0" and "Device 1" manually, this configuration does not need to correspond to their position on the cable. Pin 28 is only used to let the drives know their position on the cable; it is not used by the host when communicating with the drives. In other words, the manual master/slave setting using jumpers on the drives takes precedence and allows them to be freely placed on either connector of the ribbon cable.
With the 40-conductor cable, it was very common to implement cable select by simply cutting the pin 28 wire between the two device connectors; putting the slave "Device 1" device at the end of the cable, and the master "Device 0" on the middle connector. This arrangement eventually was standardized in later versions. However, it had one drawback: if there is just one master device on a 2-drive cable, using the middle connector, this results in an unused stub of cable, which is undesirable for physical convenience and electrical reasons. The stub causes signal reflections, particularly at higher transfer rates. Starting with the 80-conductor cable defined for use in ATAPI5/UDMA4, the master "Device 0" device goes at the far-from-the-host end of the cable on the black connector, the slave "Device 1" goes on the grey middle connector, and the blue connector goes to the host (e.g. motherboard IDE connector, or IDE card). So, if there is only one ("Device 0") device on a two-drive cable, using the black connector, there is no cable stub to cause reflections (the unused connector is now in the middle of the ribbon). Also, cable select is now implemented in the grey middle device connector, usually simply by omitting the pin 28 contact from the connector body.
Serialized, overlapped, and queued operations. The parallel ATA protocols up through ATA-3 require that once a command has been given on an ATA interface, it must complete before any subsequent command may be given. Operations on the devices must be serializedwith only one operation in progress at a timewith respect to the ATA host interface. A useful mental model is that the host ATA interface is busy with the first request for its entire duration, and therefore can not be told about another request until the first one is complete. The function of serializing requests to the interface is usually performed by a device driver in the host operating system. The ATA-4 and subsequent versions of the specification have included an "overlapped feature set" and a "queued feature set" as optional features, both being given the name "Tagged Command Queuing" (TCQ), a reference to a set of features from SCSI which the ATA version attempts to emulate. However, support for these is extremely rare in actual parallel ATA products and device drivers because these feature sets were implemented in such a way as to maintain software compatibility with its heritage as originally an extension of the ISA bus. This implementation resulted in excessive CPU utilization which largely negated the advantages of command queuing. By contrast, overlapped and queued operations have been common in other storage buses; in particular, SCSI's version of tagged command queuing had no need to be compatible with APIs designed for ISA, allowing it to attain high performance with low overhead on buses which supported first party DMA like PCI. This has long been seen as a major advantage of SCSI.
The Serial ATA standard has supported native command queueing (NCQ) since its first release, but it is an optional feature for both host adapters and target devices. Many obsolete PC motherboards do not support NCQ, but modern SATA hard disk drives and SATA solid-state drives usually support NCQ, which is not the case for removable (CD/DVD) drives because the ATAPI command set used to control them prohibits queued operations. HDD passwords and security. ATA devices may support an optional security feature which is defined in an ATA specification, and thus not specific to any brand or device. The security feature can be enabled and disabled by sending special ATA commands to the drive. If a device is locked, it will refuse all access until it is unlocked. A device can have two passwords: A User Password and a Master Password; either or both may be set. There is a Master Password identifier feature which, if supported and used, can identify the current Master Password (without disclosing it). The master password, if set, can used by the administrator to reset user password, if the end user forgot the user password. On some laptops and some business computers, their BIOS can control the ATA passwords.
A device can be locked in two modes: High security mode or Maximum security mode. Bit 8 in word 128 of the IDENTIFY response shows which mode the disk is in: 0 = High, 1 = Maximum. In High security mode, the device can be unlocked with either the User or Master password, using the "SECURITY UNLOCK DEVICE" ATA command. There is an attempt limit, normally set to 5, after which the disk must be power cycled or hard-reset before unlocking can be attempted again. Also in High security mode, the SECURITY ERASE UNIT command can be used with either the User or Master password. In Maximum security mode, the device can be unlocked only with the User password. If the User password is not available, the only remaining way to get at least the bare hardware back to a usable state is to issue the SECURITY ERASE PREPARE command, immediately followed by SECURITY ERASE UNIT. In Maximum security mode, the SECURITY ERASE UNIT command requires the Master password and will completely erase all data on the disk. Word 89 in the IDENTIFY response indicates how long the operation will take. While the ATA lock is intended to be impossible to defeat without a valid password, there are purported workarounds to unlock a device.
For NVMe drives, the security features, including lock passwords, were defined in the OPAL standard. For sanitizing entire disks, the built-in Secure Erase command is effective when implemented correctly. There have been a few reported instances of failures to erase some or all data. On some laptops and some business computers, their BIOS can utilize Secure Erase to erase all data of the disk. External parallel ATA devices. Due to a short cable length specification and shielding issues it is extremely uncommon to find external PATA devices that directly use PATA for connection to a computer. A device connected externally needs additional cable length to form a U-shaped bend so that the external device may be placed alongside, or on top of the computer case, and the standard cable length is too short to permit this. For ease of reach from motherboard to device, the connectors tend to be positioned towards the front edge of motherboards, for connection to devices protruding from the front of the computer case. This front-edge position makes extension out the back to an external device even more difficult. Ribbon cables are poorly shielded, and the standard relies upon the cabling to be installed inside a shielded computer case to meet RF emissions limits.
External hard disk drives or optical disk drives that have an internal PATA interface, use some other interface technology to bridge the distance between the external device and the computer. USB is the most common external interface, followed by Firewire. A bridge chip inside the external devices converts from the USB interface to PATA, and typically only supports a single external device without cable select or master/slave. Specifications. The following table shows the names of the versions of the ATA standards and the transfer modes and rates supported by each. Note that the transfer rate for each mode (for example, 66.7 MB/s for UDMA4, commonly called "Ultra-DMA 66", defined by ATA-5) gives its maximum theoretical transfer rate on the cable. This is simply two bytes multiplied by the effective clock rate, and presumes that every clock cycle is used to transfer end-user data. In practice, of course, protocol overhead reduces this value. Congestion on the host bus to which the ATA adapter is attached may also limit the maximum burst transfer rate. For example, the maximum data transfer rate for conventional PCI bus is 133 MB/s, and this is shared among all active devices on the bus.
In addition, no ATA hard drives existed in 2005 that were capable of measured sustained transfer rates of above 80 MB/s. Furthermore, sustained transfer rate tests do not give realistic throughput expectations for most workloads: They use I/O loads specifically designed to encounter almost no delays from seek time or rotational latency. Hard drive performance under most workloads is limited first and second by those two factors; the transfer rate on the bus is a distant third in importance. Therefore, transfer speed limits above 66 MB/s really affect performance only when the hard drive can satisfy all I/O requests by reading from its internal cache—a very unusual situation, especially considering that such data is usually already buffered by the operating system. , mechanical hard disk drives can transfer data at up to 524 MB/s, which is far beyond the capabilities of the PATA/133 specification. High-performance solid state drives can transfer data at up to 7000–7500 MB/s. Only the Ultra DMA modes use CRC to detect errors in data transfer between the controller and drive. This is a 16-bit CRC, and it is used for data blocks only. Transmission of command and status blocks do not use the fast signaling methods that would necessitate CRC. For comparison, in Serial ATA, 32-bit CRC is used for both commands and data.
Related standards, features, and proposals. ATAPI Removable Media Device (ARMD). ATAPI devices with removable media, other than CD and DVD drives, are classified as ARMD (ATAPI Removable Media Device) and can appear as either a super-floppy (non-partitioned media) or a hard drive (partitioned media) to the operating system. These can be supported as bootable devices by a BIOS complying with the ATAPI Removable Media Device BIOS Specification, originally developed by Compaq Computer Corporation and Phoenix Technologies. It specifies provisions in the BIOS of a personal computer to allow the computer to be bootstrapped from devices such as Zip drives, Jaz drives, SuperDisk (LS-120) drives, and similar devices. These devices have removable media like floppy disk drives, but capacities more commensurate with hard drives, and programming requirements unlike either. Due to limitations in the floppy controller interface most of these devices were ATAPI devices, connected to one of the host computer's ATA interfaces, similarly to a hard drive or CD-ROM device. However, existing BIOS standards did not support these devices. An ARMD-compliant BIOS allows these devices to be booted from and used under the operating system without requiring device-specific code in the OS.
A BIOS implementing ARMD allows the user to include ARMD devices in the boot search order. Usually an ARMD device is configured earlier in the boot order than the hard drive. Similarly to a floppy drive, if bootable media is present in the ARMD drive, the BIOS will boot from it; if not, the BIOS will continue in the search order, usually with the hard drive last. There are two variants of ARMD, ARMD-FDD and ARMD-HDD. Originally ARMD caused the devices to appear as a sort of very large floppy drive, either the primary floppy drive device 00h or the secondary device 01h. Some operating systems required code changes to support floppy disks with capacities far larger than any standard floppy disk drive. Also, standard-floppy disk drive emulation proved to be unsuitable for certain high-capacity floppy disk drives such as Iomega Zip drives. Later the ARMD-HDD, ARMD-"Hard disk device", variant was developed to address these issues. Under ARMD-HDD, an ARMD device appears to the BIOS and the operating system as a hard drive.
ATA over Ethernet. In August 2004, Sam Hopkins and Brantley Coile of Coraid specified a lightweight ATA over Ethernet protocol to carry ATA commands over Ethernet instead of directly connecting them to a PATA host adapter. This permitted the established block protocol to be reused in storage area network (SAN) applications. Compact Flash. Compact Flash (CF) in its "IDE mode" is essentially a miniaturized ATA interface, intended for use on devices that use flash memory storage. No interfacing chips or circuitry are required, other than to directly adapt the smaller CF socket onto the larger ATA connector. (Although most CF cards only support IDE mode up to PIO4, making them much slower in IDE mode than their CF capable speed) The ATA connector specification does not include pins for supplying power to a CF device, so power is inserted into the connector from a separate source. The exception to this is when the CF device is connected to a 44-pin ATA bus designed for 2.5-inch hard disk drives, commonly found in notebook computers, as this bus implementation must provide power to a standard hard disk drive. CF devices can be designated as devices 0 or 1 on an ATA interface, though since most CF devices offer only a single socket, it is not necessary to offer this selection to end users. Although CF can be hot-pluggable with additional design methods, by default when wired directly to an ATA interface, it is not intended to be hot-pluggable.
Atari 2600 The Atari 2600 is a home video game console developed and produced by Atari, Inc. Released in September 1977 as the Atari Video Computer System (Atari VCS), it popularized microprocessor-based hardware and games stored on swappable ROM cartridges, a format first used with the Fairchild Channel F in 1976. The VCS was bundled with two joystick controllers, a conjoined pair of paddle controllers, and a game cartridgeinitially "Combat" and later "Pac-Man". Sears sold the system as the Tele-Games Video Arcade. Atari rebranded the VCS as the Atari 2600 in November 1982, alongside the release of the Atari 5200. Atari was successful at creating arcade video games, but their development cost and limited lifespan drove CEO Nolan Bushnell to seek a programmable home system. The first inexpensive microprocessors from MOS Technology in late 1975 made this feasible. The console was prototyped under the codename Stella by Atari subsidiary Cyan Engineering. Lacking funding to complete the project, Bushnell sold Atari to Warner Communications in 1976.
The Atari VCS launched in 1977 with nine games on 2 KB cartridges. Atari ported many of their arcade games to the system, and the VCS versions of "Breakout" and "Night Driver" are in color while the arcade originals have monochrome graphics. The system's first killer application was the home conversion of Taito's "Space Invaders" in 1980. "Adventure", also released in 1980, was one of the first action-adventure video games and contains the first widely recognized Easter egg. Beginning with the VCS version of "Asteroids" in 1980, many games used bank switching to allow 8 KB or larger cartridges. By the time of the system's peak in 1982-3, games were released with significantly more advanced visuals and gameplay than the system was designed for, such as Activision's "Pitfall!". The popularity of the VCS led to the founding of Activision and other third-party game developers and competition from the Intellivision and, later, ColecoVision consoles. By 1982, the 2600 was the dominant game system in North America, and "Atari" had entered the vernacular as a synonym for the console and video games in general. However, poor decisions by Atari management damaged both the system and company's reputation, most notably the release of two highly anticipated games for the 2600: a port of the arcade game "Pac-Man" and "E.T. the Extra-Terrestrial". "Pac-Man" became the 2600's bestselling game, but was panned for not resembling the original. "E.T." was rushed to market for the holiday shopping season and was similarly disparaged. Both games, and a glut of third-party shovelware, were factors in ending Atari's significance in the console market, contributing to the video game crash of 1983.
Warner sold the assets of Atari's consumer electronics division to former Commodore CEO Jack Tramiel in 1984. In 1986, the new Atari Corporation under Tramiel released a revised, low-cost 2600 model, and the backward-compatible Atari 7800, but it was Nintendo that led the recovery of the industry with its 1985 launch of the Nintendo Entertainment System. Production of the Atari 2600 ended in 1992, with an estimated 30 million units sold across its lifetime. History. Atari, Inc. was founded by Nolan Bushnell and Ted Dabney in 1972. Its first major product was "Pong", released in 1972, the first successful coin-operated video game. While Atari continued to develop new arcade games in following years, "Pong" gave rise to a number of competitors to the growing arcade game market. The competition along with other missteps by Atari led to financial problems in 1974, though recovering by the end of the year. By 1975, Atari had released a "Pong" home console, competing against Magnavox, the only other major producer of home consoles at the time. Atari engineers recognized, however, the limitation of custom logic integrated onto the circuit board, permanently confining the whole console to only one game. The increasing competition increased the risk, as Atari had found with past arcade games and again with dedicated home consoles. Both platforms are built from integrating discrete electro-mechanical components into circuits, rather than programmed as on a mainframe computer. Thus, development of a console had cost at least plus time to complete, but the final product only had about a three-month shelf life until becoming outdated by competition.
By 1974, Atari had acquired Cyan Engineering, a Grass Valley electronics company founded by Steve Mayer and Larry Emmons, both former colleagues of Bushnell and Dabney from Ampex, who helped to develop new ideas for Atari's arcade games. Even before the release of the home version of "Pong", Cyan's engineers, led by Mayer and Ron Milner, had envisioned a home console powered by new programmable microprocessors capable of playing Atari's current arcade offerings. The programmable microprocessors would make a console's design significantly simpler and more powerful than any dedicated single-game unit. However, the cost of such chips was far outside the range that their market would tolerate. Atari had opened negotiations to use Motorola's new 6800 in future systems. MOS Technology 6502/6507. In September 1975, MOS Technology debuted the 6502 microprocessor for at the Wescon trade show in San Francisco. Mayer and Milner attended, and met with the leader of the team that created the chip, Chuck Peddle. They proposed using the 6502 in a game console, and offered to discuss it further at Cyan's facilities after the show.
Over two days, MOS and Cyan engineers sketched out a 6502-based console design by Meyer and Milner's specifications. Financial models showed that even at , the 6502 would be too expensive, and Peddle offered them a planned 6507 microprocessor, a cost-reduced version of the 6502, and MOS's RIOT chip for input/output. Cyan and MOS negotiated the 6507 and RIOT chips at a pair. MOS also introduced Cyan to Microcomputer Associates, who had separately developed debugging software and hardware for MOS, and had developed the JOLT Computer for testing the 6502, which Peddle suggested would be useful for Atari and Cyan to use while developing their system. Milner was able to demonstrate a proof-of-concept for a programmable console by implementing "Tank", an arcade game by Atari's subsidiary Kee Games, on the JOLT. As part of the deal, Atari wanted a second source of the chipset. Peddle and Paivinen suggested Synertek whose co-founder, Bob Schreiner, was a friend of Peddle. In October 1975, Atari informed the market that it was moving forward with MOS. The Motorola sales team had already told its management that the Atari deal was finalized, and Motorola management was livid. They announced a lawsuit against MOS the next week.
Building the system. By December 1975, Atari hired Joe Decuir, a recent graduate from University of California, Berkeley who had been doing his own testing on the 6502. Decuir began debugging the first prototype designed by Mayer and Milner, which gained the codename "Stella" after the brand of Decuir's bicycle. This prototype included a breadboard-level design of the graphics interface to build upon. A second prototype was completed by March 1976 with the help of Jay Miner, who created a chip called the Television Interface Adaptor (TIA) to send graphics and audio to a television. The second prototype included a TIA, a 6507, and a ROM cartridge slot and adapter. As the TIA's design was refined, Al Alcorn brought in Atari's game developers to provide input on features. There are significant limitations in the 6507, the TIA, and other components, so the programmers creatively optimized their games to maximize the console. The console lacks a framebuffer and requires games to instruct the system to generate graphics in synchronization with the electron gun in the cathode-ray tube (CRT) as it scans across rows on the screen. The programmers found ways to "race the beam" to perform other functions while the electron gun scans outside of the visible screen.
Alongside the electronics development, Bushnell brought in Gene Landrum, a consultant who had just prior consulted for Fairchild Camera and Instrument for its upcoming Channel F, to determine the consumer requirements for the console. In his final report, Landrum suggested a living room aesthetic, with a wood grain finish, and the cartridges must be "idiot proof, child proof and effective in resisting potential static [electricity] problems in a living room environment". Landrum recommended it include four to five dedicated games in addition to the cartridges, but this was dropped in the final designs. The cartridge design was done by James Asher and Douglas Hardy. Hardy had been an engineer for Fairchild and helped in the initial design of the Channel F cartridges, but he quit to join Atari in 1976. The interior of the cartridge that Asher and Hardy designed was sufficiently different to avoid patent conflicts, but the exterior components were directly influenced by the Channel F to help work around the static electricity concerns.
Atari was still recovering from its 1974 financial woes and needed additional capital to fully enter the home console market, though Bushnell was wary of being beholden to outside financial sources.> Atari obtained smaller investments through 1975, but not at the scale it needed, and began considering a sale to a larger firm by early 1976. Atari was introduced to Warner Communications, which saw the potential for the growing video game industry to help offset declining profits from its film and music divisions. Negotiations took place during 1976, during which Atari cleared itself of liabilities, including settling a patent infringement lawsuit with Magnavox over Ralph H. Baer's patents that were the basis for the Magnavox Odyssey. In mid-1976, Fairchild announced the Channel F, planned for release later that year, beating Atari to the market. By October 1976, Warner and Atari agreed to the purchase of Atari for . Warner provided an estimated which was enough to fast-track Stella. By 1977, development had advanced enough to brand it the "Atari Video Computer System" (VCS) and start developing games.
Launch and success. The unit was showcased on June 4, 1977, at the Summer Consumer Electronics Show with plans for retail release in October. The announcement was purportedly delayed to wait out the terms of the Magnavox patent lawsuit settlement, which would have given Magnavox all technical information on any of Atari's products announced between June 1, 1976, and June 1, 1977. However, Atari encountered production problems during its first batch, and its testing was complicated by the use of cartridges. The Atari VCS was launched in September 1977 at , with two joysticks and a "Combat" cartridge; eight additional games were sold separately. Most of the launch games were based on arcade games developed by Atari or its subsidiary Kee Games: for example, "Combat" was based on Kee's "Tank" (1974) and Atari's "Jet Fighter" (1975). Atari sold between 350,000 and 400,000 Atari VCS units during 1977, attributed to the delay in shipping the units and consumers' unfamiliarity with a swappable-cartridge console that is not dedicated to only one game.
In 1978, Atari sold only 550,000 of the 800,000 systems manufactured. This required further financial support from Warner to cover losses. Bushnell pushed the Warner Board of Directors to start working on "Stella 2", as he grew concerned that rising competition and aging tech specs of the VCS would render the console obsolete. However, the board stayed committed to the VCS and ignored Bushnell's advice, leading to his departure from Atari in 1979. Atari sold about 600,000 VCS systems in 1979, bringing the installed base to a little over 1.3 million. Atari obtained a license from Taito to develop a VCS conversion of its 1978 arcade hit "Space Invaders". This is the first officially licensed arcade conversion for a home console. Atari sold 1.25 million "Space Invaders" cartridges and over 1 million VCS systems in 1980, nearly doubling the install base to over 2 million, and then an estimated 3.1 million VCS systems in 1981. By 1982, 10 million consoles had been sold in the United States, while its best-selling game was "Pac-Man" at over copies sold by 1990. "Pac-Man" propelled worldwide Atari VCS sales to units during 1982, according to a November 1983 article in "InfoWorld" magazine. An August 1984 "InfoWorld" magazine article says more than Atari 2600 machines were sold by 1982. A March 1983 article in "IEEE Spectrum" magazine has about 3 million VCS sales in 1981, about 5.5 million in 1982, as well as a total of over 12 million VCS systems and an estimated 120 million cartridges sold.
In Europe, the Atari VCS sold 125,000 units in the United Kingdom during 1980, and 450,000 in West Germany by 1984. In France, where the VCS released in 1982, the system sold 600,000 units by 1989. The console was distributed by Epoch Co. in Japan in 1979 under the name "Cassette TV Game", but did not sell as well as Epoch's own Cassette Vision system in 1981. In 1982, Atari launched its second programmable console, the Atari 5200. To standardize naming, the VCS was renamed to the "Atari 2600 Video Computer System", or "Atari 2600", derived from the manufacture part number CX2600. By 1982, the 2600 cost Atari about to make and was sold for an average of . The company spent .50 to to manufacture each cartridge, plus to for advertising, wholesaling for . Third-party development. Activision, formed by Crane, Whitehead, and Miller in 1979, started developing third-party VCS games using their knowledge of VCS design and programming tricks and began releasing games in 1980. "Kaboom!" (1981) and "Pitfall!" (1982) are among the most successful with at least one and four million copies sold, respectively. In 1980, Atari attempted to block the sale of the Activision cartridges, accusing the four of intellectual property infringement. The two companies settled out of court, with Activision agreeing to pay Atari a licensing fee for their games. This made Activision the first third-party video game developer and established the licensing model that continues to be used by console manufacturers for game development.
Activision's success led to the establishment of other third-party VCS game developers following Activision's model in the early 1980s, including U.S. Games, Telesys, Games by Apollo, Data Age, Zimag, Mystique, and CommaVid. The founding of Imagic included ex-Atari programmers. Mattel and Coleco, each already producing its own more advanced console, created simplified versions of their existing games for the 2600. Mattel used the M Network brand name for its cartridges. Third-party games accounted for half of VCS game sales by 1982. Decline and redesign. In addition to third-party game development, Atari also received the first major threat to its hardware dominance from the ColecoVision. Coleco had a license from Nintendo to develop a version of the arcade game "Donkey Kong" (1981), which was bundled with every ColecoVision console. Coleco gained about 17% of the hardware market in 1982 compared to Atari's 58%. With third parties competing for market share, Atari worked to maintain dominance in the market by acquiring licenses for popular arcade games and other properties to make games from. "Pac-Man" has numerous technical and aesthetic flaws, but nevertheless more than 7 million copies were sold. Heading into the 1982 holiday shopping season, Atari had placed high sales expectations on "E.T. the Extra-Terrestrial", a game programmed in about six weeks. Atari produced an estimated four million cartridges, but the game was poorly reviewed, and only about 1.5 million units were sold.
Warner Communications issued revised earnings guidance in December 1982 to its shareholders, having expected a 50% year-to-year growth but now only expecting 10–15% due to declining sales at Atari. Coupled with the oversaturated home game market, Atari's weakened position led investors to start pulling funds out of video games, beginning a cascade of disastrous effects known as the video game crash of 1983. Many of the third-party developers formed prior to 1983 were closed, and Mattel and Coleco left the video game market by 1985. In September 1983, Atari sent 14 truckloads of unsold Atari 2600 cartridges and other equipment to a landfill in the New Mexico desert, later labeled the Atari video game burial. Long considered an urban legend that claimed the burial contained millions of unsold cartridges, the site was excavated in 2014, confirming reports from former Atari executives that only about 700,000 cartridges had actually been buried. Atari reported a loss for 1983 as a whole, and continued to lose money into 1984, with a loss reported in the second quarter. By mid-1984, software development for the 2600 had essentially stopped except that of Atari and Activision.
Warner, wary of supporting its failing Atari division, started looking for buyers in 1984. Warner sold most of the assets of Atari's counsumer electronics and home computer divisions to Jack Tramiel, the founder of Commodore International, in July 1984 in a deal valued at , though Warner retained Atari's arcade business. Tramiel was a proponent of personal computers, and halted all new 2600 game development soon after the sale. The North American video game market did not recover until about 1986, after Nintendo's 1985 launch of the Nintendo Entertainment System in North America. Atari Corporation released a redesigned model of the 2600 in 1986, supported by an ad campaign touting a price of "under 50 bucks". With a large library of cartridges and a low price point, the 2600 continued to sell into the late 1980s. Atari released the last batch of games in 1989–90 including "Secret Quest" and "Fatal Run". By 1986, over Atari VCS units had been sold worldwide. The final Atari-licensed release is the PAL-only version of the arcade game "KLAX" in 1990.
After more than 14 years on the market, 2600 production ended in 1992, along with the Atari 7800 and Atari 8-bit computers. Despite this fact, Atari continued sells in Europe for years to come. It cost less than £39.99 and was mainly distributed through mail order chains. In 1991, 200,000 units were sold on the continent and in it was a bestseller at Littlewoods stores in UK. After the fall of communism, Atari attempted to legally introduce the Atari 2600 and 7800 to the former Eastern Bloc countries, with small price being main advantage of the system, but Atari was defeated by even more cheaper and easily available clones called "Rambo TV Game 2600" (advertised with the 1982 movie character Rambo played by Sylvester Stallone), containing up to several hundred built-in games. In Western Europe, last stocks of the 2600 and 7800 were sold until Summer/Fall of 1995. Hardware. The Atari 2600's CPU is the MOS Technology 6507, a version of the 6502, running at 1.19 MHz in the 2600. Though their internal silicon was identical, the 6507 was cheaper than the 6502 because its package included fewer memory-address pins—13 instead of 16. The designers of the Atari 2600 selected an inexpensive cartridge interface that has one fewer address pins than the 13 allowed by the 6507, further reducing the already limited addressable memory from 8 KB (213 = 8,192) to 4 KB (212 = 4,096). This was believed to be sufficient as "Combat" was only 2 KB. Later games circumvented this limitation with bank switching.
The console has 128 bytes of RAM for scratch space, the call stack, and the state of the game environment. The top bezel of the console originally had six switches: power, TV type selection (color or black-and-white), game selection, left and right player difficulty, and game reset. The difficulty switches were moved to the back of the bezel in later versions of the console. The back bezel also included the controller ports, TV output, and power input. Graphics. The Atari 2600 was designed to be compatible with the cathode-ray tube television sets produced in the late 1970s and early 1980s, which commonly lack auxiliary video inputs to receive audio and video from another device. Therefore, to connect to a TV, the console generates a radio frequency signal compatible with the regional television standards (NTSC, PAL, or SECAM), using a special switch box to act as the television's antenna. Atari developed the Television Interface Adaptor (TIA) chip in the VCS to handle the graphics and conversion to a television signal. It provides a single-color, 20-bit background register that covers the left half of the screen (each bit represents 4 adjacent pixels) and is either repeated or reflected on the right side. There are 5 single-color sprites: two 8-pixel wide "players"; two 1 bit "missiles", which share the same colors as the players; and a 1-pixel "ball", which shares the background color. The 1-bit sprites all can be controlled to stretch to 1, 2, 4, or 8 pixels.
The system was designed without a frame buffer to avoid the cost of the associated RAM. The background and sprites apply to a single scan line, and as the display is output to the television, the program can change colors, sprite positions, and background settings. The careful timing required to sync the code to the screen on the part of the programmer was labeled "racing the beam"; the actual game logic runs when the television beam is outside of the visible area of the screen. Early games for the system use the same visuals for pairs of scan lines, giving a lower vertical resolution, to allow more time for the next row of graphics to be prepared. Later games, such as "Pitfall!", change the visuals for each scan line or extend the black areas around the screen to extend the game code's processing time. Regional releases of the Atari 2600 use modified TIA chips for each region's television formats, which require games to be developed and published separately for each region. All modes are 160 pixels wide. NTSC mode provides 192 visible lines per screen, drawn at 60 Hz, with 16 colors, each at 8 levels of brightness. PAL mode provides more vertical scanlines, with 228 visible lines per screen, but drawn at 50 Hz and only 13 colors. SECAM mode, also a 50 Hz format, is limited to 8 colors, each with only a single brightness level.
Controllers. The first VCS bundle has two types of controllers: a joystick (part number CX10) and pair of rotary paddle controllers (CX30). Driving controllers, which are similar to paddle controllers but can be continuously rotated, shipped with the "Indy 500" launch game. After less than a year, the CX10 joystick was replaced with the CX40 model designed by James C. Asher. Because the Atari joystick port and CX40 joystick became industry standards, 2600 joysticks and some other peripherals work with later systems, including the MSX, Commodore 64, Amiga, Atari 8-bit computers, and Atari ST. The CX40 joystick can be used with the Master System and Sega Genesis, but does not provide all the buttons of a native controller. Third-party controllers include Wico's Command Control joystick. Later, the CX42 Remote Control Joysticks, similar in appearance but using wireless technology, were released, together with a receiver whose wires could be inserted in the controller jacks. Atari introduced the CX50 Keyboard Controller in June 1978 along with two games that require it: "Codebreaker" and "Hunt & Score". The similar, but simpler, CX23 Kid's Controller was released later for a series of games aimed at a younger audience. The CX22 Trak-Ball controller was announced in January 1983 and is compatible with the Atari 8-bit computers.
There were two attempts to turn the Atari 2600 into a keyboard-equipped home computer: Atari's never-released CX3000 "Graduate" keyboard, and the CompuMate keyboard by Spectravideo which was released in 1983. Console models. Minor revisions. The initial production of the VCS was made in Sunnyvale during 1977, using thick polystyrene plastic for the casing as to give the impression of weight from what was mostly an empty shell inside. The initial Sunnyvale batch had also included potential mounts for an internal speaker system on the casing, though the speakers were found to be too expensive to include; instead sound was routed through the TIA to the connected television. All six console switches were mounted on the front panel. Production of the unit was moved to Taiwan in 1978, where a less thick internal metal shielding was used and thinner plastic was used for the casing, reducing the system's weight. These two versions are commonly referred to as "Heavy Sixers" and "Light Sixers" respectively, referencing the six front switches.
In 1980, the difficulty switches were moved to the back of the console, leaving four switches on the front and replacing the previous all lowercase font for the switch labels to fully capitalized wording. Otherwise, these four-switch consoles look nearly identical to the earlier six-switch models. In 1982, to coincide with the release of the Atari 5200, Atari rebranded the console as the "Atari 2600", a name first used on a version of the four-switch model without woodgrain, giving it an all-black appearance. This all-black model is commonly referred to by fans as the "Vader" model, due to its resemblance to the "Star Wars" character of the same name. Sears Video Arcade. Atari continued its OEM relationship with Sears under the latter's Tele-Games brand, which started in 1975 with the original "Pong". This is unrelated to the company Telegames, which later produced 2600 cartridges. Sears released several models of the VCS as the Sears Video Arcade series starting in 1977. The final Sears-specific model was the Video Arcade II, released during the fall of 1982.
Sears released versions of Atari's games with Tele-Games branding, usually with different titles. Three games were produced by Atari for Sears as exclusive releases: "Steeplechase", "Stellar Track", and "Submarine Commander". Atari 2800. The Atari 2800 is the Japanese version of the 2600 released in October 1983. It is the first Japan-specific release of a 2600, though companies like Epoch had distributed the 2600 in Japan previously. The 2800 was released a short time after Nintendo's Family Computer (which became the dominant console in Japan), and it did not gain a significant share of the market. Sears previously released the 2800 in the US during late 1982 as the Sears Video Arcade II, which came packaged with two controllers and "Space Invaders". Around 30 specially branded games were released for the 2800. Designed by engineer Joe Tilly, the 2800 has four controller ports instead of the two of the 2600. The controllers are an all-in one design using a combination of an 8-direction digital joystick and a 270-degree paddle, designed by John Amber. The 2800's case design departed from the 2600, using a wedge shape with non-protruding switches. The case style is the basis for the Atari 7800, which was redesigned for the 7800 by Barney Huang. 1986 model.
The cost-reduced 1986 model, sometimes referred to as the "2600 Jr.", has a smaller form factor with an Atari 7800-like appearance. It was advertised as a budget gaming system (under ) with the ability to run a large collection of games. Released after the video game crash of 1983, and after the North American launch of the Nintendo Entertainment System, the 2600 was supported with new games and television commercials promoting "The fun is back!". Atari released several minor stylistic variations: the "large rainbow" (shown), "short rainbow", and an all-black version sold only in Ireland. Later European versions include a joypad. Unreleased prototypes. The Atari 2700 was a version of the 2600 with wireless controllers. The CX2000, with integrated joystick controllers, was a redesign based on human factor analysis by Henry Dreyfuss Associates. The circa-1982 Atari 3200 was a backwards compatible 2600 successor with "more memory, higher resolution graphics and improved sound". Related hardware and recreations.
The Atari 7800, announced in 1984 and released in 1986, is the official successor to the Atari 2600 and is backward compatible with 2600 cartridges. Multiple retro-style consoles and microconsoles have been released since the lifespan of the original Atari 2600: Games. In 1977, nine games were released on cartridge to accompany the launch of the console: "Air-Sea Battle", "Basic Math", "Blackjack", "Combat", "Indy 500", "Star Ship", "Street Racer", "Surround", and "Video Olympics". "Indy 500" shipped with special "driving controllers", which are like paddles but rotate freely. "Street Racer" and "Video Olympics" use the standard paddle controllers. Atari, Inc. was the only developer for the first few years, releasing dozens of games. Atari determined that box art featuring only descriptions of the game and screenshots would not be sufficient to sell games in retail stores, since most games were based on abstract principles and screenshots give little information. Atari outsourced box art to Cliff Spohn, who created visually interesting artwork with implications of dynamic movement intended to engage the player's imagination while staying true to the gameplay. Spohn's style became a standard for Atari when bringing in assistant artists, including Susan Jaekel, Rick Guidice, John Enright, and Steve Hendricks. Spohn and Hendricks were the largest contributors to the covers in the Atari 2600 library. Ralph McQuarrie, a concept artist on the "Star Wars" series, was commissioned for one cover, the arcade conversion of "Vanguard". These artists generally conferred with the programmer to learn about the game before drawing the art.
An Atari VCS port of the "Breakout" arcade game appeared in 1978. The original is in black and white with a colored overlay, and the home version is in color. In 1980, Atari released "Adventure", the first action-adventure game, and the first home game with a hidden Easter egg. Rick Maurer's port of Taito's "Space Invaders", released in 1980, was the first VCS game to sell a million copies—eventually doubling that within a year and totaling more than cartridges by 1983. It became the killer app to drive console sales. Versions of Atari's own "Asteroids" and "Missile Command" arcade games, released in 1981, were also major hits. Launch games use 2K ROMs. 4K eventually became standard with games such as "Space Invaders". The VCS port of "Asteroids" (1981) was the first game for the system to use 8K via a bank switching technique between two 4K segments. Some games including Atari's ports of "Dig Dug" and "Crystal Castles", are 16K cartridges. One of the final games, "Fatal Run" (1990), doubled this to 32K. Many early VCS titles were able to display in both monochrome (black and white) and full color through the use of the "TV type" switch on the console. This allowed the VCS games to function on both monochrome and color televisions. However, beginning around the rebranding from "VCS" to "2600", support for black and white display modes diminished greatly, with most releases during this period only displaying in color and the TV type switch serving no function. Late releases such as "Secret Quest", began using the TV type switch for gameplay functions, such as pausing.
Two Atari-published games, both from the system's peak in 1982, "E.T. the Extra-Terrestrial" and "Pac-Man", were rushed to market and are cited as factors in the video game crash of 1983. A company named American Multiple Industries produced a number of pornographic games for the 2600 under the "Mystique Presents Swedish Erotica" label. The most notorious, "Custer's Revenge", was protested by women's and Native American groups because it depicted General George Armstrong Custer raping a bound Native American woman. Atari sued American Multiple Industries in court over the release of the game. Legacy. The 2600 was so successful in the late 1970s and early 1980s that "Atari" was a synonym for the console in mainstream media and for video games in general. Jay Miner directed the creation of the successors to the 2600's TIA chip—CTIA and ANTIC—which are central to the Atari 8-bit computers released in 1979 and later the Atari 5200 console. The Atari 2600 was inducted into the National Toy Hall of Fame at The Strong in Rochester, New York, in 2007. In 2009, the Atari 2600 was named the number two console of all time by IGN, which cited its remarkable role behind both the first video game boom and the video game crash of 1983, and called it "the console that our entire industry is built upon".
In November 2021, the current incarnation of Atari announced three 2600 games to be published under "Atari XP" label: "Yars' Return", "Aquaventure", and "Saboteur". These were previously included in Atari Flashback consoles. A model of the Atari 2600 was released by Lego in 2022. Included are the three games "Asteroid", "Centipede", and "Adventure". Included is a minifigure with a bedroom designed from the 1980s.
Atari 5200 The Atari 5200 SuperSystem or simply Atari 5200 is a home video game console introduced in 1982 by Atari, Inc. as a higher-end complement for the popular Atari Video Computer System. The VCS was renamed to Atari 2600 at the time of the 5200's launch. Created to compete with Mattel's Intellivision, the 5200 wound up a direct competitor of ColecoVision shortly after its release. While the Coleco system shipped with the first home version of Nintendo's "Donkey Kong", the 5200 included the 1978 arcade game "Super Breakout", which had already appeared on previous Atari home platforms. The system architecture is almost identical to that of the Atari 8-bit computers, although software is not directly compatible between them. The 5200's controllers have an analog joystick and a numeric keypad along with start, pause, and reset buttons. The 360-degree non-centering joystick was touted as offering more control than the eight-way Atari CX40 joystick of the 2600, but it was a focal point for criticism. On May 21, 1984, during a press conference at which the Atari 7800 was introduced, company executives revealed that the 5200 had been discontinued after less than two years on the market. Total sales of the system were reportedly in excess of 1 million units, far short of its predecessor's sales of over 30 million.
Hardware. Following the release of the Video Computer System in 1977, Atari began developing hardware for a next generation game console. Instead, it was used as the basis for the Atari 400 and 800 home computers. Atari later decided to re-enter the console market using the same technology. Prototypes were called the "Atari Video System X – Advanced Video Computer System". Actual working "Atari Video System X" machines, whose hardware is 100% identical to the Atari 5200, do exist, but they are extremely rare. The initial 1982 release of the system had four controller ports, compared to two in most other consoles. The controllers have an analog joystick, numeric keypad, two fire buttons on each side of the controller, and game function keys for Start, Pause, and Reset. The 5200 also featured the innovation of the first automatic TV switchbox, allowing it to automatically switch from regular TV viewing to the game system signal when the system was activated. Previous RF adapters required the user to slide a switch on the adapter by hand. The RF box was also where the power supply connected in a unique dual power/television signal setup similar to the RCA Studio II's. A single cable coming out of the 5200 plugged into the switch box and carried both electricity and the television signal.
The 1983 revision of the Atari 5200 has two controller ports instead of four, and a change back to the more conventional separate power supply and standard non-autoswitching RF switch. It also has changes in the cartridge port address lines to allow for the Atari 2600 adapter released that year. While the adapter was only made to work on the two-port version, modifications can be made to the four-port to make it line-compatible. In fact, towards the end of the four-port model's production run, there were a limited number of consoles produced which included these modifications. These consoles can be identified by an asterisk in their serial numbers. At one point following the 5200's release, Atari planned a smaller, cost-reduced version of the Atari 5200, which removed the controller storage bin. Code-named the "Atari 5100" (a.k.a. "Atari 5200 Jr."), only a few fully working prototype 5100s were made before the project was canceled. Controllers. The controller prototypes used in the electrical development lab employed a yoke-and-gimbal mechanism that came from an RC airplane controller kit. The design of the analog joystick, which used a weak rubber boot rather than springs to provide centering, proved to be ungainly and unreliable. They quickly became the Achilles' heel of the system due to the combination of an overly complex mechanical design and a very low-cost internal flex circuit system. Another major flaw of the controllers was that the design did not translate into a linear acceleration from the center through the arc of the stick travel. The controllers did, however, include a pause button, a unique feature at the time. Various third-party replacement joysticks were also released, including those made by Wico.
Atari Inc. released the Pro-Line Trak-Ball controller, which was used for games such as "Centipede" and "Missile Command". A paddle controller and an updated self-centering version of the original controller were also in development, but never made it to market. Games were shipped with plastic card overlays that snapped in over the keypad. The cards indicated which game functions, such as changing the view or vehicle speed, were assigned to each key. The primary controller was ranked the 10th worst video game controller by IGN editor Craig Harris. An editor for "Next Generation" said that their non-centering joysticks "rendered many games nearly unplayable". Differences from Atari 8-bit computers. David H. Ahl in 1983 described the Atari 5200 as "a 400 computer in disguise". Its internal design is similar to that of Atari 8-bit computers using the ANTIC, POKEY, and GTIA coprocessors. Software designed for one does not run on the other, but source code can be mechanically converted unless it uses computer-specific features. "Antic" magazine reported in 1984 that "the similarities grossly outweigh the differences, so that a 5200 program can be developed and almost entirely debugged [on an Atari 8-bit computer] before testing on a 5200". John J. Anderson of "Creative Computing" alluded to the incompatibility being intentional, caused by Atari's console division removing 8-bit compatibility to not lose control to the rival computer division.
Besides the 5200's lack of a keyboard, the differences are: In 1987, Atari Corporation released the XE Game System console, which is a repackaged 65XE (from 1985) with a detachable keyboard that can run home computer titles directly, unlike the 5200. Anderson wrote in 1984 that Atari could have released a console compatible with computer software in 1981. Reception. The Atari 5200 did not fare well commercially compared to its predecessor, the Atari 2600. While it touted superior graphics to the 2600 and Mattel's Intellivision, the system was initially incompatible with the 2600's expansive library of games, and some market analysts have speculated that this hurt its sales, especially since an Atari 2600 cartridge adapter had been released for the Intellivision II. (A revised two-port model was released in 1983, along with a game adapter that allowed gamers to play all 2600 games.) This lack of new games was due in part to a lack of funding, with Atari continuing to develop most of its games for the saturated 2600 market.
Many of the 5200's games appeared simply as updated versions of 2600 titles, which failed to excite consumers. Its pack-in game, "Super Breakout", was criticized for not doing enough to demonstrate the system's capabilities. This gave the ColecoVision a significant advantage as its pack-in, "Donkey Kong", delivered a more authentic arcade experience than any previous game cartridge. In its list of the top 25 game consoles of all time, IGN claimed that the main reason for the 5200's market failure was the technological superiority of its competitor, while other sources maintain that the two consoles are roughly equivalent in power. The 5200 received much criticism for the "sloppy" design of its non-centering analog controllers. Anderson described the controllers as "absolutely atrocious". David H. Ahl of "Creative Computing Video & Arcade Games" said in 1983 that the "Atari 5200 is, dare I say it, Atari's answer to Intellivision, Colecovision, and the Astrocade", describing the console as a "true mass market" version of the Atari 8-bit computers despite the software incompatibility. He criticized the joystick's imprecise control but said that "it is at least as good as many other controllers", and wondered why "Super Breakout" was the pack-in game when it did not use the 5200's improved graphics.
Popular culture. Critical to the plot of the 1984 film "Cloak & Dagger" is an Atari 5200 game cartridge called "Cloak & Dagger". The arcade version appears in the movie. In actuality the Atari 5200 version was started but never completed. The game was under development with the title "Agent X" when the movie producers and Atari learned of each other's projects and decided to cooperate. This collaboration was part of a larger phenomenon, of films featuring video games as critical plot elements (as with "Tron" and "The Last Starfighter") and of video game tie-ins to the same films (as with the "Tron" games for the Intellivision and other platforms).
Atari 7800 The Atari 7800 ProSystem, or simply the Atari 7800, is a home video game console officially released by Atari Corporation in 1986 as the successor to both the Atari 2600 and Atari 5200. It can run almost all Atari 2600 cartridges, making it the first ever console with backward compatibility. It shipped with a different joystick than the 2600-standard CX40 and included "Pole Position II" as the pack-in game. The European model has a gamepad instead of a joystick. Most of the early releases for the system are ports of 1981–1983 arcade video games. The final wave of 7800 cartridges are closer in style to what was available on other late 1980s consoles, such as "Scrapyard Dog" and "Midnight Mutants". Designed by General Computer Corporation, the 7800 has graphics hardware similar to early 1980s arcade video games and is a significant improvement over Atari's previous consoles. It uses same Television Interface Adaptor chip that launched with the 2600 in 1977 to generate two-channel audio. In an effort to prevent the flood of poor quality games that contributed to the video game crash of 1983, cartridges had to be digitally signed by Atari.
The Atari 7800 was first announced by Atari, Inc. on May 21, 1984, but a general release was shelved until May 1986 due to the sale of the company. Atari Corporation dropped support for the 7800, along with the 2600 and the Atari 8-bit computers, on January 1, 1992. History. The Atari 7800 ProSystem was the first console from Atari, Inc. designed by an outside company: General Computer Corporation. It was developed in 1983–84 with an intended mass market rollout in June 1984, but was canceled after the sale of the company to Tramel Technology Ltd on July 2, 1984. The project was originally called the Atari 3600. With a background in creating arcade games such as "Food Fight", GCC designed the new system with a graphics architecture similar to arcade machines of the time. The CPU is a slightly customized 6502 processor, the Atari SALLY, running at 1.79 MHz. By some measures the 7800 is more powerful, and by others less, than the 1983 Nintendo Entertainment System. It uses the 2600's Television Interface Adaptor chip, with the same restrictions, for generating two-channels of audio.
Launch. The 7800 was announced on May 21, 1984. Thirteen games were announced for the system's launch: "Ms. Pac-Man", "Pole Position II", "Centipede", "Joust", "Dig Dug", "Nile Flyer" (eventually released as "Desert Falcon"), "", "Galaga", "Food Fight", "Ballblazer", "Rescue on Fractalus!" (later canceled), "Track & Field", and "Xevious". It was a significant technological leap over the Atari 2600 and Atari 5200. On July 2, 1984, Warner Communications sold Atari's Consumer Division to Jack Tramiel. All projects were halted during an initial evaluation period. GCC had not been paid for their development of the 7800, and Warner and Tramiel fought over who was accountable. In May 1985, Tramiel relented and paid GCC. This led to additional negotiations regarding the launch titles GCC had developed, then an effort to find someone to lead their new video game division, which was completed in November 1985. The original production run of the Atari 7800 languished in warehouses until it was introduced in January 1986.
The console was released nationwide in May 1986 for $79.95 with games intended for the 7800's debut in 1984. It was aided by a marketing campaign with a budget in the "low millions" according to Atari Corporation officials. This was substantially less than the $9 million spent by Sega and the $16 million spent by Nintendo. The keyboard and high score cartridge planned by Warner were cancelled. The 7800 addressed many of the most common complaints with the preceding 5200, including a smaller size, built-in backward compatibility, and an improved controller design. In February 1987, "Computer Entertainer" reported that 100,000 Atari 7800 consoles had been sold in the United States, including those which had been warehoused since 1984. This was less than the Master System's 125,000 and the NES's 1.1 million. Games were slowly released: "Galaga" in August, followed by "Xevious" in November. By the end of 1986, the 7800 had 10 games, compared to Sega's 20 and Nintendo's 36. Atari would sell over 1 million 7800 consoles by June 1988.
Discontinuation. On January 1, 1992, Atari Corporation announced the end of production and support for the 7800, 2600, and the 8-bit computer family including the Atari XEGS. At least one game, an unreleased port of "Toki", was worked on past this date. By the time of the discontinuation, the Nintendo Entertainment System controlled 80% of the North American market while Atari had 12%. In Europe, last stocks of the 7800 were sold until summer/fall of 1995. "Retro Gamer" magazine issue 132 reported that according to Atari UK Marketing Manager Darryl Still, "it was very well stocked by European retail; although it never got the consumer traction that the 2600 did, I remember we used to sell a lot of units through mail order catalogues and in the less affluent areas". Technical specifications. Graphics. Graphics are generated by the custom MARIA chip, which uses an approach common in contemporary arcade system boards and is different from other second and third generation consoles. Instead of a limited number of hardware sprites, MARIA treats everything as a sprite described in a series of display lists. Each display list contains pointers to graphics data and color and positioning information.
MARIA supports a palette of 256 colors and graphics modes which are either 160 pixels wide or 320 pixels wide. While the 320 pixel modes theoretically enable the 7800 to create games at higher resolution than the 256 pixel wide graphics found in the Nintendo Entertainment System and Master System, the processing demands of MARIA result in most games using the 160 pixel mode. Each sprite can have from 1 to 12 colors, with 3 colors plus transparency being the most common. In this format, the sprite references one of 8 palettes, where each palette holds 3 colors. The background (visible when not covered by other objects) can also be assigned a color. In total, 25 colors can appear on a scan line. The graphics resolution, color palettes, and background color can be adjusted between scan lines. Sound. The 7800 uses the TIA chip for two channel audio, the same chip used in the 1977 Atari VCS, and the sound is of the same quality as that system. To compensate, GCC's engineers allowed games to include a POKEY audio chip in the cartridge. Only "Ballblazer" and "Commando" do this.
GCC planned to make a low-cost, high performance sound chip, GUMBY, which could also be placed in 7800 cartridges to enhance its sound capabilities further. This project was cancelled when Atari was sold to Jack Tramiel. Digitally signed cartridges. Following the large number of low quality, third party games for the Atari 2600, Atari required that cartridges for the 7800 be digitally signed. When a cartridge is inserted into the system, the BIOS generates a signature of the cartridge ROM and compares it to the one stored on the cartridge. If they match, the console operates in 7800 mode, granting the game access to MARIA and other features, otherwise the console operates as a 2600. This digital signature code is not present in PAL 7800s, which use various heuristics to detect 2600 cartridges, due to export restrictions. Backward compatibility. The 7800's compatibility with the Atari 2600 is made possible by including many of the same chips used in the 2600. When playing an Atari 2600 game, the 7800 uses a Television Interface Adaptor chip to generate graphics and sound. The processor is slowed to 1.19 MHz, to mirror the performance of the 2600's 6507 chip. RAM is limited to 128 bytes and cartridge data is accessed in 4K blocks.
When in 7800 mode (signified by the appearance of the full-screen Atari logo), the graphics are generated entirely by the MARIA graphics processing unit. All system RAM is available and cartridge data is accessed in larger 48K blocks. The system's SALLY 6502 runs at its normal 1.79 MHz. The 2600 chips are used to generate sound and to provide the interfaces to the controllers and console switches. Peripherals. The Atari 7800 came bundled with the Atari Pro-Line Joystick, a two-button controller with a joystick for movement. The Pro-Line was developed for the 2600 and advertised in 1983, but delayed until Atari proceeded with the 7800. The right fire button only works as a separate fire button for certain 7800 games; otherwise, it duplicates the left fire button, allowing either button to be used for 2600 games. While physically compatible, the 7800's controllers do not work with the Sega Master System, and Sega's controllers are unable to use the 7800's two-button mode. In response to criticism over ergonomic issues with the Pro-Line controllers, Atari later released a joypad controller with the European 7800. Similar in style to controllers found on Nintendo and Sega systems, it was not available in the United States.
The Atari XG-1 light gun, bundled with the Atari XEGS and also sold separately, is compatible with the 7800. Atari released five 7800 light gun games: "Alien Brigade", "Barnyard Blaster", "Crossbow", "Meltdown", and "Sentinel". Cancelled peripherals. After the acquisition of the Atari Consumer Division by Jack Tramiel in 1984, several expansion options for the system were cancelled: Games. While the system can play the over 400 games for the Atari 2600, there were only 59 official releases for the 7800. The lineup emphasized high-quality versions of games from the golden age of arcade video games. "Pole Position II", "Dig Dug", and "Galaga", by the time of the 1986 launch, were three, four, and five years old, respectively. A raster graphics version of 1979's "Asteroids" was released in 1987. In 1988, Atari published a conversion of Nintendo's "Donkey Kong", seven years after the original arcade game and five years after the Atari 8-bit computer cartridge. Atari also marketed a line of games called "Super Games" which were arcade and computer games previously not playable on a home console such as "" and "Impossible Mission".
Eleven games were developed and sold by three third-party companies under their own labels (Absolute Entertainment, Activision, and Froggo) with the rest published by Atari Corporation. Most of the games from Atari were developed by outside companies under contract. Some NES games were developed by companies who had licensed their title from a different arcade manufacturer. While the creator of the NES version would be restricted from making a competitive version of an NES game, the original arcade copyright holder was not precluded from licensing out rights for a home version of an arcade game to multiple systems. Through this loophole, Atari 7800 conversions of "Mario Bros.", "Double Dragon", "Commando", "Rampage", "Xenophobe", "Ikari Warriors", and "Kung-Fu Master" were licensed and developed. A final batch of games was released by Atari in 1990: "Alien Brigade", "Basketbrawl", "Fatal Run", "Meltdown", "Midnight Mutants", "MotorPsycho", "Ninja Golf", "Planet Smashers", and "Scrapyard Dog". "Scrapyard Dog" was later released for the Atari Lynx.
Legacy. Atari Flashback. In 2004, the Infogrames-owned version of Atari released the Atari Flashback console. It resembles a miniature Atari 7800 and has five 7800 and fifteen 2600 games built-in. Built using the NES-On-A-Chip hardware instead of recreating the Atari 7800 hardware, it was criticized for failing to properly replicate the actual gaming experience. A subsequent 7800 project was cancelled after prototypes were made. Game development. The digital signature long prevented aftermarket games from being developed. The signing software was eventually found and released at Classic Gaming Expo in 2001. Several new Atari 7800 games such as "Beef Drop", "B*nQ", "Combat 1990", "CrazyBrix", "Failsafe", and "Santa Simon" have been released.. Source code. In July 2009, the source code to 13 games, the operating system, and Atari ST-hosted development tools, were released. Commented assembly language source code was made available for "Centipede", "Commando", "Crossbow", "Desert Falcon", "Dig Dug", "Food Fight", "Galaga", "Hat Trick", "Joust", "Ms. Pac-Man", "Super Stunt Cycle", "", and "Xevious". Atari 7800+. In late 2024, Atari Inc. and Plaion released the "Atari 7800+", a microconsole designed as a smaller-scale replica of the 7800, specifically the European model. It includes support for physical cartridges of both the Atari 2600 and Atari 7800 though emulation. It is effectively a variant of the Atari 2600+, which was introduced in 2023.
Atari Jaguar The Atari Jaguar is a home video game console developed by Atari Corporation and released in North America in November 1993. It is in the fifth generation of video game consoles, and it competed with fourth generation consoles, including the 16-bit Genesis, the 16-bit Super NES, and the 32-bit 3DO Interactive Multiplayer. Jaguar has a Motorola 68000 CPU and two custom 32-bit coprocessors named Tom and Jerry. Atari marketed it as the world's first 64-bit game system, emphasizing the blitter's 64-bit bus; however, none of its three processors have a 64-bit instruction set, as do later 64-bit consoles such as PlayStation 2 and Nintendo 64. The Jaguar launched with "Cybermorph" as the pack-in game, which received mixed reviews. The system's library ultimately comprises only 50 licensed games. Development started in the early 1990s by Flare Technology, which focused on the system after cancellation of the Panther console. The Jaguar was an important system for Atari after discontinuing Atari ST computers in favor of video games. However, game development was complicated by the multi-chip architecture, hardware bugs, and poor programming tools. Underwhelming sales further eroded third-party support.
Atari attempted to extend the system's lifespan with the Jaguar CD add-on, with an additional 13 games, and emphasizing the Jaguar's price of over less than its competitors. However, Jaguar could not compete against the Saturn and PlayStation, both released in 1995. Atari had internally abandoned the system by the end of that year, liquidating its inventory by 1996. The commercial failure of the Jaguar prompted Atari to leave the console market, and restructure itself as a third-party developer. After Hasbro Interactive acquired all Atari Corporation properties, it released the Jaguar patents into the public domain in 1999, and declared it an open platform. Since its discontinuation, hobbyists have produced games for the system. History. Development. Atari Corporation's previous home video game console, the 7800, was released in 1986. It was considered an "also-ran" and far behind rival Nintendo. Around 1989, work began on a new console leveraging technology from Atari ST computers. It was originally named the Super XE, following the XE Game System, and eventually became the Panther using either 16 or 32-bit architecture. A more advanced system codenamed Jaguar also began work.

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