CompuShow installer format

File Format
Name	CompuShow installer format
Ontology	Electronic File Formats Archiving CompuShow installer format
Released	≤1994

CompuShow installer format is an EXE-based installer file for DOS.

It was used for distribution of some software by Canyon State Systems:

• CompuShow, v8.70-9.04
• CompuShow 2000, v1.03-2.04
• CompuLog, v1.00-2.01

A typical filename is "CSHOWA.EXE", but note that not all files with this name use this format.

Format details

The format is somewhat convoluted. The main executable part is compressed with PKLITE. The overlay segment (refer to MS-DOS EXE#Special file positions) uses a tagged format of undetermined origin. The overlay starts with ASCII "FBIN". The main part of the payload is an LHA/LHarc self-extracting archive contained in an item identified by "FBEX".

Software

• Deark
• Some LHA software is robust enough that it can often handle these files.

Sample files

• CSHOW73.ZIP → CSHOWA.EXE [This is v8.73a, with a misleading filename.]
• 2SHOW204.ZIP → 2SHOWA.EXE
• cmplg201.zip → CMPLGA.EXE