Asc2Com
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== Format details == | == Format details == | ||
| − | Version 2.00+ has an option to compress the embedded text with [[LZW]]. | + | |
| + | === Compression scheme === | ||
| + | Version 2.00+ has an option to compress the embedded text with [[LZW]]. Here are some notes on the compression scheme. | ||
| + | |||
| + | Code size is 9 to 10 bits. Special codes: | ||
| + | |||
| + | {| class="wikitable" style="font-size: 85%;" | ||
| + | | 256 || Unused or unknown. | ||
| + | |- | ||
| + | | 257 || Increment code size (from 9 to 10). Seek to the next byte boundary. | ||
| + | |- | ||
| + | | 258 || Stop. | ||
| + | |} | ||
| + | |||
| + | The first dynamic code is 259. The code table is never cleared. | ||
| + | |||
| + | The Asc2Com documentation includes some very minimal information about its LZW format. | ||
== Identification == | == Identification == | ||
Revision as of 14:26, 27 October 2024
Asc2Com is a DOS utility that converts a text document to a COM file that, when executed, displays the text in a viewer. It was developed by MorganSoft. It supports a number of different viewing styles and options.
Contents |
Discussion
The software was originally in the form of a command-line utility named Asc2Com. Later versions include both a menu-driven utility named Asc2Com, and a command-line utility named A2C.
Depending on the version, and the options used when generating the COM file, it may have a feature (Alt-F or Alt-W) to write the text to a disk file. Run the file, and try pressing F1 for help.
Format details
Compression scheme
Version 2.00+ has an option to compress the embedded text with LZW. Here are some notes on the compression scheme.
Code size is 9 to 10 bits. Special codes:
| 256 | Unused or unknown. |
| 257 | Increment code size (from 9 to 10). Seek to the next byte boundary. |
| 258 | Stop. |
The first dynamic code is 259. The code table is never cleared.
The Asc2Com documentation includes some very minimal information about its LZW format.
Identification
It appears difficult to precisely identify files made by Asc2Com.
Generated files usually contain one of the following ASCII strings somewhere in them:
- "
Com File Generated by ASC2COM" (Used by older versions.) - "
Com File generated by ASC2COM" - "
File made by ASC2COM"
Known exceptions:
- Compressed v2.01 files contain "
ASC2COM V2.00,COMPRESS". - Compressed v2.05 files contain "
ASC2COM V2.01,COMPRESS".
Software
- Asc2Com
- v1.10b
- v1.25 and v1.25b (no copy found)
- v1.30
- v1.50 (no copy found)
- v1.65 (no copy found)
- v1.66: DISK1948.ZIP → ASC2C166.LZH
- v1.75: Frostbyte's 1980s DOS Shareware Collection → floppyshareware.zip → LUNACY/ASC2C175.ZIP
- v1.76
- v2.00
- v2.00f: a2c20f.exe - Patch to upgrade v2.00 to v2.00f
- v2.01
- v2.05
- Deark
Sample files
- BTX.ZIP → *.COM
- AMORT21.ZIP → *.COM
- TMCAP311.ZIP → *.COM
- FRAMEGRB.ZIP → INFO1.COM
- twplanet.zip → README.COM
- ada301a.zip → README.COM (Made by v1.25?)
- dexvert samples — document/asc2com
