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would always execute the second version, leaving the first for dead. This makes debugging software incredibly easy because any incorrectly-defined words can be tested as they are entered and continually |
hacked about until they reach a correct form. Because all previous attempts at the same word are kept in the dictionary, you can return to these at any time. When |
the definitive version of the word has been created, you can save memory space by deleting with Replace all the intermediate attempts. Unlike most implementations of Forth, the Ace has |
a substantial level of error-checking. For example, the stack will not overflow. It is also made more powerful by the ability to redefine words without the system crashing. However, should |
you require yet more speed than normally available, there is a Fast command. This does away with the error-checking, so it is wise to use it only when a program |
is totally debugged. It takes the computer’s speed up to about 90 percent of a machine-coded program, but it does disable the break key. At an end-user price of £89.95, |
the Jupiter Ace is an excellent way of learning an important new computer language. It will have a special appeal to those who feel that they have now grown out |
of their ZX-81s, especially as far as Basic programming is concerned. It will also be a Godsend to those who want the speed and economy of machine code but cannot |
grasp its principles. The Jupiter Ace comes in a white plastic case, not all that dissimilar in style to the now-defunct ZX-80′s horrible box. It is undoubtedly the machine’s worst |
feature, and the cost-cutting that has been done here could turn out to be that ha’porth of tar that spoilt the ship. The printing on the case is in a |
matt-black, broken only by a series of red lines. These red lines are obviously the microcomputer world’s equivalent of the “go-faster” stripes that teenage car owners sport to make their |
old Ford Cortinas look a little sleeker. The truth of the matter is that the Jupiter is very fast. The manufacturer claims that it is the fastest microcomputer in this |
quadrant of the galaxy. This has a lot to do with the rapidity of the Forth language, but some of the credit has to go to the Z-80A processor which |
nips along at a rate of knots — 3.25MHz to be precise. Speed implies heat, but there is not much danger of the Jupiter overheating, or at least a sight |
less danger than some machines, because inside that flimsy plastic case is plenty of breathing room and what is more, the case is better ventilated than that of the ZX |
range of computers. Sinclair cognoscenti will smile when they peer inside the case and see the heat sink. I often wonder why they are such odd shapes — could it |
be they were designed by Picasso? Comparisons with the Sinclair machines will inevitably keep cropping up, because the designers of the Ace were, until recently, in the employ of Sinclair |
Research and so take some of the credit and blame for the ZX Spectrum. Apart from the gross departure of choosing the Forth language, the design is fairly standard. Sinclair |
owners will find much inside the Ace’s case that is familiar to them. The keyboard closely resembles that on the ZX-81, both in the number of keys and their layout. |
But rather than having those horrid little squares that you have to struggle to push down as you program, the Ace uses a rubbery “moving-key” design. Personally I find it |
is a little like shaking a dead man’s hand. The keys do at least have the advantage of being readable — that is, there are none of the Spectrum’s red |
words which you can only track down using special spectacles. Another small mercy that we can thank Jupiter for — or Zeus if you are Greek — is that there |
is no single-keyword entry to contend with. However, the designers probably did not abandon it for any good reason, but merely because the infinity of word names available to Forth |
makes it impracticable. There are also some significant advances. For example, there are both upper and lower-case letters. It is also possible for the user to define his own character |
set — in fact by doing so, some reasonably high-resolution graphics are possible. In this way the graphics of the Ace remind me of a non-colour Spectrum. In normal mode |
there are 32 character positions across the display and 24 down. In the Plot mode, there is a resolution of 64 by 48 points — not exactly high resolution. If |
you are prepared to play about with the character definition then this increases to a respectable 192 by 256. The operation of the word Plot is like the other Forth |
words. The top three numbers on the stack are the parameters which are passed to a machine-code routine. At the top of the stack is a number which describes how |
the point is to be drawn, and the next two give its screen location. Probably the biggest advantage of the Ace’s picture quality over the ZX-81′s is that the Ace |
has a rock-steady black screen on which any printing appears in white: the ZX-81 docs the reverse which is not a natural way for a computer to behave. The two |
machines certainly have a good deal in common, apart from the designer. The review machine did not have a power supply. That was no problem because I used the Sinclair |
Research one, which worked perfectly. The user port on the rear of the Ace, closely resembles that on the Sinclair machines. It is not difficult to justify this as there |
are not really many ways of presenting the Z-80 lines at the edge of a board. Any device that connects to the rear of a Sinclair computer will snugly fit |
on the back of the Ace. All that is needed is a special cable that unshuffles the lines. It will probably take a few months at least for a budding |
Forth programmer to need more than the 3K of user RAM that comes as standard with the Ace, but should you ever require more, the Sinclair 16K RAM pack will |
fit the bill. Forth was originally designed as a control language, and the Jupiter Ace makes a fine control computer. In fact, this may become its eventual role. There are |
two words, In and Out for controlling the data lines. Put the Ace together with any of the available add on hardware designed for the Sinclair, and you have a |
powerful control system. The way forward Other features available on the Ace include a speaker, which can operate right across the audio range. But, like the Spectrum’s, it is very |
quiet. It is controlled by the ROM-word Beep, and can be manipulated very easily by the language. Again, Forth is ideal for this kind of programming, and musical sequences are |
among the easiest things to write on the Ace. There is also a quartz timer, which doubles as the system clock. This can be accessed from Forth and has a |
expect the most common use for such a facility will be in the timing of responses and in the generation of random numbers. Here is a very crude random-number generator: |
out from the main card. Eventually it will be used for a colour video generator. - The success of the Jupiter Ace will depend on the machine-buying public’s acceptance of |
another microcomputer language. - The machine’s development is certainly a brave gamble on behalf of its manufacturers. - It will be of great interest to scientists, those with control applications, |
ZX-81 machine-code fans, educationalists and professional programmers who feel they cannot ignore the language. - Home-computer users who have progressed beyond the beginner phase will like the language and the |
Japan has been hit by the worst crisis since 1945, as an earthquake and tsunami have killed 10,000, destroyed tens of thousands of buildings, displaced hundreds of thousands, and left millions without power or water. As the nation braces for |
more aftershocks, people have resorted to using sea water in an attempt to prevent a nuclear meltdown from adding a third catastrophe, which has already leaked and caused a mass evacuation. According to Greenpeace, "We are told by the nuclear |
industry that things like this cannot happen with modern reactors, yet Japan is in the middle of a nuclear crisis with potentially devastating consequences…The evolving situation at Fukushima remains far from clear, but what we do know is that contamination |
from the release of Cesium-137 poses a significant health risk to anyone exposed. Cesium-137 has been one if the isotopes causing the greatest health impacts following the Chernobyl disaster, because it can remain in the environment and food chain for |
300 years.” Whereas the first two catastrophe’s were natural and unpredictable, a nuclear meltdown is entirely unnatural and entirely predictable. According to the local anti-nuclear group, Citizens’ Nuclear Information Centre, The nuclear crisis comes a month before the 25th anniversary |
of the Chernobyl disaster, the largest nuclear meltdown in history, which showered Europe in a radioactive cloud causing a quarter of a million cancers, 100,000 of them fatal. As of this writing the disaster in Japan is already the third |
worst in history, behind Chernobyl and the Three Mile Island partial meltdown in 1979, and comes only 12 years after a fatal overexposure of workers at a nuclear plant in Tokaimura, Japan. Even without the inherent risk of a meltdown, |
nuclear power is a threat to health. The problem is not just the few terrible times when they don't work, but the daily experience of when they do work. As climate campaigner George Monbiot wrote more than a decade ago, |
“The children of women who have worked in nuclear installations, according to a study by the National Radiological Protection Board, are eleven times more likely to contract cancer than the children of workers in non-radioactive industries. You can tell how |
close to [the nuclear plant in] Sellafield children live by the amount of plutonium in their teeth.” Add to this the morbidity and mortality or working in uranium mines and the dangers of disposing of radioactive waste, and you have |
negative health impacts at every stage of nuclear power (for a summary see the UK’s Campaign for Nuclear Disarmament). Despite this, governments have invested massively in the nuclear industry and globalized the risk. Canada has exported nuclear reactors while building |
seven of its own, and despite concerns about safety the Ontario government plans on investing $36 billion into nuclear power at the same time as its backing off wind power. REASONS AND EXCUSES While nuclear power is a clear and |
present danger to the health of the planet and its people, it is a thriving industry driven by economic and military competition. Vandana Shiva—who studied nuclear physics and now leads the climate justice movement in India—has exposed the hypocrisy of |
US hostility to Iranian nuclear power when it is doing the same thing to promote nuclear power and weapons in India as a bulwark against China: As Shiva summarized in her book Soil Not Oil, “nuclear winter is not an |
alternative to global warming”, and it is a tragedy that Japan has become the test case against both military and civilian arms of the nuclear industry--from the atomic bomb 65 years ago to the nuclear meltdown today. But instead of |
admitting the problems of nuclear power, the nuclear industry and its supporters have greenwashed it and presented it as a solution to global warming. Some environmentalists, such as Gaia theorist James Lovelock, have fallen prey to these claims. Lovelock, whose |
ideas are driven by apocalyptic predictions and an extreme pessimism, has gone so far as to claim that “nuclear power is the only green solution”.While former US president George Bush defended his country’s 103 nuclear power plants as not producing |
"a single pound of air pollution or greenhouses gases”, Dr. Helen Caldicott has refuted the claim in her important book Nuclear Power is Not the Answer, which proves that even without meltdowns nuclear power is a threat to the planet: |
The false dichotomy between carbon emissions and nuclear power is also refuted by those developing the Tar Sands, who have proposed using nuclear power to pump Tar Sands oil. PEOPLE POWER, GREEN JOBS Fortunately there are growing anti-nuclear campaigns uniting |
indigenous groups, NGOs and the broader climate justice movement to challenge nuclear power in all its stages—from mining to use to waste disporal. As Vandana Shiva writes in Soil Not Oil, Meanwhile in Canada indigenous groups are leading opposition to |
transportation of nuclear waste through the Great Lakes and their surrounding communities, declaring “what we do to the land, we do to ourselves.” Last year the German government extended nuclear power against the will of the majority but after news |
of the leak in Japan, 50,000 people formed a human chain from a nuclear reactor to Stuttgart demanding an end to nuclear power. Uniting these campaigns with the labour movement raises the demands of good green jobs for all, to |
transform our oil and nuclear economy into one based on ecological and social sustainability and justice. Instead of the billions in subsidies for the nuclear industry, governments could be investing in solar, wind and clean electricity, while retrofitting buildings, which |
could solve the economic and climate crises without the inherent dangers of nuclear power. As Greenpeace wrote, "Our thoughts continue to be with the Japanese people as they face the threat of a nuclear disaster, following already devastating earthquake and |
tsunami. The authorities must focus on keeping people safe, and avoiding any further releases of radioactivity...Greenpeace is calling for the phase out of existing reactors, and no construction of new commercial nuclear reactors. Governments should invest in renewable energy resources |
be sites of melt-through from below. They are wide-ranging in size, location and age. Most are similar to Conamara with a matrix reminiscent of frozen slush, and often rafts of |
pre-existing crust. Edges are of two types: ramps, perhaps the tapering of crustal thickness to zero, or cliffs where rafts appear to have broken clear from the shore. Of the |
lenticulae, "spots" generally appear to be small chaoses with textured matrix and occasional rafts, "pits" may represent incipient melting nearly at the surface, and many "domes" may be small chaoses |
raised by isostatic compensation following refreezing of the crust. The extent of chaoses often appears to be limited by ridge systems with the coastline parallel and set back by a |
distance comparable to the width of the ridge system. Pre-existing ridges often survive as causeways or chains of rafts. Boundaries of chaoses are apparently not controlled by pre-existing cracks, evidence |
that formation is essentially a thermal, rather than mechanical process. Evidently ridges thicken the crust such that melt-through is more likely between ridge systems. Subsequent cracks and ridges form across |
pre-existing chaoses: Recent chaoses have few cracks or ridges across them (with paths somewhat jagged as they meander among rafts), while the remains of old chaoses are only isolated rafts |
surrounded by densely ridged terrain. Thus two fundamental resurfacing processes have alternated over Europa's geological history: melt-through (at various places and times) forming chaos terrain, and criss-crossing by cracking and |
ridge-building forming densely ridged (and other tectonic) terrain. Mapping of chaos features based on morphology at 200 m shows that they correlate well with dark regions in global (2 km |
resolution) mosaics (except dark regions due to ridge margins or craters), so considerable area has been available to accommodate the expansion of crust that occurs along extensional bands and ridges. |
Chaos ubiquity suggests Europan geology has been dominated by the effects of having liquid water under a very thin ice shell, with chaos regions being widespread examples of zero shell |
We are six weeks into the 2010-11 school year, and now that the dust has settled, some inspiration has hit to get me blogging again. Recently, a third grade teacher asked me if there were any podcasts “out there” that taught the parts of speech. She was looking for some |
reinforcement for the nouns work that they were doing in the classroom. This would be a good avenue to reach the different learning styles in her classroom. Excited to get iPods into the hands of third graders, I did a little searching and came across this tremendous resource that I |
would like to share: mrcoley.com . This site has wonderful examples of podcasts by both students and teacher (and one fit the bill for the parts of speech topic); however, this site is has even more to offer beyond podcasts. It has gotten me and some of the teachers at |
my school thinking about how we can use our Nanos in a whole new way: for flash cards. It’s a basic concept that Mr. Brent Coley, a 5th grade teacher, explains with step by step directions and tutorials (Thank you!). Using PowerPoint or Keynote, make simple slides that teach or |
as math facts, adding in the element of a timer. Now, third graders are trying to “beat the iPod” to the answer! Sure, the students could do their fact practice with paper flash cards, but this “hook” of using the iPods makes the learning very exciting and motivating. One teacher |
reported to me that 19 sets of earbuds came in on one day’s notice. (Students have to supply their own earbuds to use our Nanos, and if you don’t have earbuds, you can’t use them.) She said that getting permission slips back in a timely fashion never happens, but using |
an iPod got their attention! Engagement is up! (Even in the bus line on the way home, students enthusiastically were telling me that their teacher was signing out the iPods again for another lesson.) Wondering how slides will look on something as small as an iPod Nano? Here’s what an |
Explorer review that I created looks like: Nothing fancy, but it is easy to read. Its linear fashion allows a student to review for the benchmark by reading a question on one slide and then following up with the answer on the next one. Everything doesn’t have to be in |
a quiz format either. Perhaps, a teacher could take a PowerPoint that was used to teach a lesson and convert it to work on the iPods, too. Students could use the lesson for reference to do assignments or to study at school or at home on their own device. The |
Search: Advanced search Browse by category: My question is how do we know whether to say Ittaqullah and not Attaqullah or Uttaqullah. Assalamu Alaikum wa Rahmatullahi wa Barakatuh Kindly explain |
the rules of how to read a word when one needs to seperate it from the word before it for example I know that when we seperate Ya Ayyuhallazina Amanuttaqullaha |
and want to say 'fear Allah' on its own, we say Ittaqullaha. My question is how do we know whether to say Ittaqullah and not Attaqullah or Uttaqullah. I remember |
learning the rule long ago, something to do with the sign (fathah, dhamma, kasra) on the next letter, but have since forgotten. Please explain with examples from the Qur'an. Jazak |
Allahi Kkhair Wa alaikum assalaam wa rahmatullahi wa barakatuh, The rules involved in the question are the hamzah al-wasl rules. We have to look at the word beginning with the |
hamzah al-wasl and determine whether it is a verb, a noun, or a participle. In this case, the word is a command form of a verb. In a verb starting |
with hamzah al-wasl, we look at the vowel on the third letter, if it is a fathah or a kasrah, then we start the hamzah al-wasl with a kasrah. To |
see the detailed lessons on hamzah al-wasl, please see the following link. You will find many examples in the eight different lessons insha' Allah: Wa iyyaaakum wa-l-muslimeen. Powered by KBPublisher |
This is a language dependent introduction course on computer program design and development. Emphasis is on the identification and solution of business problems through systems of computer programs. Programs are described and designed through such tools as program flowcharts, structure |
charts, and pseudocode. Within this framework, programming languages are treated as tools which can be selected, as appropriate, to implement the designs. This course provides the foundation for a program of study in computer science. It introduces the discipline of |
computing and the roles of professionals. A contemporary high-level language with appropriate constructs for structured design and structured types is presented. It integrates an introduction to algorithm design, an understanding of abstraction applied to date types and structures, and an |
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