RED (Knowledge Dynamics)

File Format
Name	RED (Knowledge Dynamics)
Ontology	Electronic File Formats Archiving RED (Knowledge Dynamics)
Extension(s)	.red, .lif, others

.RED is an installer-archive format, apparently associated with INSTALL for DOS, and maybe other software from Knowledge Dynamics Corporation (of Canyon Lake, Texas, later San Antonio).

The identifier "RED" is probably derived from "Reduce", which is the name of a software component and a proprietary compression algorithm.

See also LIF (Knowledge Dynamics), the presumed predecessor format.

Format details

[This section contains unofficial information based on reverse engineering. It was written for the fileformats.archiveteam.org wiki.]

A RED archive is a sequence of member file structures, each with the following fields:

Offset	Size	Description
0	2	Signature: ASCII "RR"
2	1	Unknown, always 0x01.
3	1	Header size, from the start of the RR signature. Always(?) 41.
4	4	DOS time, date
8	4	Compressed size
12	4	Decompressed size
16	2	Probably reserved for CRC of compressed data, but none of the known compression schemes use it.
18	2	CRC of decompressed data
20	2	Segment number. The first segment is 1. Used with multi-part archives. This field is usually 0 for single-part archives.
22	2	"Is last segment" flag
24	2	Compression scheme. 1 is uncompressed. See below for scheme 11.
26	13	Filename
39	2	CRC of header, excluding the signature and this field.
41	...	Compressed data

Compression

Compression scheme 11 compresses the data with LHA's "lh5" scheme, then segments it. The compressed data is split into segments of 4094 bytes (fewer for the last segment), and a two-byte CRC (of the compressed data in the segment) is inserted at the end of each segment.

CRC

The CRC algorithm is CRC-16/IBM-3740. Though RED is mainly a little-endian format, some of the CRC fields use big-endian byte order.

Identification

RED files apparently start with bytes 'R' 'R' 0x01 0x29.

Software

• Reduce - INSTALL Format Librarian (An interactive DOS utility)
  • Reduce v3.20.02: [1]
  • Reduce v3.20.04: [2]
  • Reduce v3.31: [3]

Sample files

• BBS Software Directory: PCBOARD → pcb153-*.zip → ...
• dexvert samples — archive/redArchive

Links

• INSTALL website (1999 archive)