text
stringlengths
0
99.6k
squeeze, or un-squash an archive.
If your application requires a large number of graphics
screens, or a great deal of text you could cram at least
twice as much information on a disk using random access
archives!
ARC VERSION 2.20 PAGE - 50
Choosing the Compressor Manually
ARC now lets you choose the method of storage yourself.
The most useful option is when you opt to crunch all files
in a single pass. If disk storage is a consideration, then
the following rules of thumb can be used to decide when to
choose this option and when to avoid it.
If you let ARC choose the most efficient compressor,
then you will find that:
1) Text files almost always CRUNCH.
2) Word Pro or Paperclip files almost always CRUNCH.
3) BASIC programs almost always CRUNCH.
4) Machine language programs less than 40 blocks will
usually CRUNCH and sometimes SQUASH.
5) Larger ML programs usually SQUASH and occasionally
SQUEEZE or PACK.
6) Graphics images either CRUNCH or SQUASH (50:50)
and occasionally PACK
At present there is no version of ARC for Commodore
computers other than the 64. Eventually there will be at
least a program that will extract archives on a PET, VIC or
what have you. The CRUNCH routines require a large amount of
RAM memory (about 32K or more), so if you are archiving
material for a PET or VIC or any other machine that has less
than 32K RAM, you should avoid CRUNCHing files.
INTRODUCTION 2
Freeware 2
Disclaimer 4
Updates 5
Version numbers 6
Bugs in ARC 7
Intro to ARC 8
Drive letters 10
General DOS commands 12
Set default drive 12
Execute program 12
Set date 12
Viewing a disk directory 13
Scratching files 13
Moving files between drives 14
Renaming files 14
Viewing a file's contents 14
DOS wedge 15
Size 15
Start 15
editor commands. 16
selecting text or BASIC mode. 16
Automatic line numbering 16
RESET the computer. 16
Change 17
Delete lines 17
Find text 17
Load sequential file 17
Disable ARC 18
Renumber lines 18
Save Sequential file 18
Repeat/Off 18
Un-NEW 18
Hex to Decimal conversions 18
ARC 19
Creating Archives 19
Appending to existing archives 21
Notes on XMODEM 21
Extracting files from an archive 23
Archive directories 24
Typing a file in an archive 25
Printer setup 25
Verifying an archive 26
MEMORY MAP 27
THEORY OF OPERATION 28
Run length coding (packing) 28
Huffman coding (squeezing) 30
Squeeze example 32
Lempel Zev Compression (crunching) 35
Crunch example 35
Archive file format 38
The header 38
Stored Files 38
Packed Files 38
Squeezed or Squashed Files 39