Retro7zip

Retro7zip is a native backport of 7-Zip for DOS and Win32c that runs on old Microsoft operating systems.

System Requirements

• DOS 3.3 / 386 CPU / 4MB RAM
• FreeDOS, MS-DOS, PC-DOS, SvarDOS, or IBM OS/2
• Windows 95, Windows 98, Windows Me, Windows NT 3.51, or Windows NT 4.0

Installation

On FreeDOS, download the versioned release file and do this:

RENAME 7zip-24.09+3_dos.zip 7zip.zip
FDNPKG INSTALL 7zip.zip

On any other platform, unzip the release file and put the BIN files anywhere in the %PATH%.

7-Zip Variants

The release package for DOS contains three executable files:

1. 7zm.exe Mini for DOS

Runs on computers that have less than 8 megabytes of memory. Implements only the BCJ2 filter, LZMA2 codec, and 7Z container that are used in regular 7-Zip archives.

2. 7zr.exe Reduced for DOS

Runs best on computers that have at least 8 megabytes of memory. Implements all filters, codecs, and containers for the archive formats that 7-Zip can read and write. (7z, bz2, gz, tar, xz, zip.)

3. 7za.exe Aggregated for DOS

Contains all upstream features, including support for filesystem images and exotic archive formats. Requires more than 8 megabytes of memory to unpack some complex files. (Run 7za i for a complete list of supported types.)

And the release package for Windows contains one executable file:

4. 7za.exe Aggregated for Win32c

Use this program if you need:

• Large file sizes on Windows 9x, because DOS applications have a 2GB limit.
• Long file names on Windows NT, because the NTVDM lacks the LFN API that DOS applications use.

The DOS variants are compatible with NTLFN.EXE 0.81.71, but the Win32c variant is better for Windows NT.

Licensing

The LZMA SDK is copyright Igor Pavlov and released into the public domain.

7-Zip is an aggregate work, copyright Igor Pavlov, that is subject to multiple licenses that are described in the COPYRIGHT.txt file and the License.txt file.

Retro7zip is a derived work, copyright Darik Horn, that is released into the public domain.