EDI Install packed file

EDI Install packed file refers to the compressed file formats associated with certain versions of the EDI Install family of software by Eschalon Development and Robert Salesas.

This article covers EDI Install files with signatures "EDILZSS1" and "EDILZSS2". Later versions of the software use a different format: EDI Install archive.

Discussion
There seems to be at least three main product lines, with independent version numbering schemes:
 * EDI Install for MS-DOS
 * EDI Install for Windows
 * EDI Install Pro for Windows, a.k.a. EDI Install Pro

The evaluation copies generally did not include the compression/decompression utilities, which were provided upon registration. For some versions, the decompression routine is integrated into the installation software, so a separate utility is not needed, though such a utility may still exist.

At least for EDILZSS1 format, the decompression utilities (UNPACK.EXE, DUNPACK.EXE, WUNPACK.EXE(?)) were redistributable, and can be found in some third-party software distributions.

The EDILZSS2 format was apparently used by, at least, EDI Install Pro v2.10 and v2.5, but no copies of these versions have been found.

File structure
The EDILZSS1 file structure seems to be:
 * 8-byte signature: " ".
 * Original filename, NUL-terminated, padded to 13 bytes.
 * Compressed data.

The EDILZSS2 file structure seems to be:
 * 8-byte signature: " ".
 * Original filename, NUL-terminated, padded to 13 bytes.
 * Original file size, as a 4-byte integer.
 * Compressed data.

For both formats, the compressed data format is similar or identical to Okumura's LZSS.

Identification
Files start with ASCII "" or "".

Unfortunately, the "EDILZSS1" signature is also used by EDI LZSSLib, a different format.

Software

 * → DUNPACK.EXE - Unpack v1.00 (DOS software, for "EDILZSS1")
 * → UNPACK.EXE - EDI Unpack v2.00 (Windows 3.x software, for "EDILZSS1")
 * → UNPACK.EXE - A different build of EDI Unpack v2.00

EDI Install distributions:


 * EDI Install for MS-DOS, v1.0
 * → insdos.zip
 * Garbo archive → pub/pc/garbo/pc/util/insdos.zip

See also EDI Install archive.

Sample files
(The name of a compressed file often ends in '$' or '_'.)

EDILSZZ1:

EDILZSS2: