Exomizer 3 website

Exomizer is a program that compresses files in a way that tries to be as efficient as possible but still allows them to be decompressed in environments where CPU speed and RAM are limited. For some popular 8-bit computers using 6502 compatible CPUs it can also generate executable files that decompress themselves in memory when run.

The exomizer program itself is a console application written in ANSI-C.

Exomizer operates in two major modes. It has a raw mode that compresses plain files and produces plain files. This mode is used by the raw subcommand. All other subcommands use the second mode. It requires all source files to be targeted to be decrunched at specific addresses in the 16-bit address space of the target computer. In this mode, no file can be larger than 64kB since all data must be addressable using 16-bits. The targeted mode has the following features:

It reads plain or .prg files to any given address.
It can produce stand-alone self-decrunching files for the following targets:
- Commodore VIC20, C64, C65, C16/plus4, C128 and PET 4032
- Atari 400/800 XL/XE
- Apple ][+ and //e
- Oric-1 and Oric Atmos
- BBC Micro B
It can produce files for both "in memory" and "from disk" decrunching.
It handles RLE-sequences well, no packer is necessary.
It is able to link/combine more than one source file into the same crunched target file.

Included in the downloadable zip file are the source code and a precompiled binary for Win32. It also includes a makefile for Gnu make and gcc so it should be easy to build on any system where these tools are available.

Any suggestions, comments and/or bug reports can be sent to me, the author.

2023-11-25: Exomizer v3.1.2 released

Changes since the 3.1.1 release:

Change to zlib license for all files not contributed by others.
The logic in the sfx decruncher should also check if the setup copy area accesses RAM below ROM when deciding ram_during. Bug reported by Comos.
The desfx sub command should only consider mem areas created after setup for detection of the decrunched data. Bug reported by Gi-Joe.
Make c65 sfx target disable IRQ:s on exit in more situations.
Fix Atari 8bit sfx zero page addr collision.
Improve zp-usage and fix sfx basic for target PET 4032.
The exodecr/exodecrunch.s 6502 decruncher now also exists in a version for kick assembler.

A complete changelog is included in the zip file. Download it here.

2021-05-22: Exomizer v3.1.1 released

Major changes since the 3.1.0 release:

New sfx target, -t 65, for the Commodore c65 and the MEGA65 computer.
New -y option to the sfx command to add text to the end of the generated SYS-line.

(download removed)

2020-12-22: Exomizer v3.1.0 released

Changes since the 3.0.2 release:

Improved compression on average due to offset reuse.
Add experimental split encoding feature for encoding reuse which is a gain when compressing similar small files (only supported by 6502 decruncher).
New Intel 8080 decompressor by Ivan Gorodetsky
New ARM 32bit thumb2 decompressor by ALeX Kazik
Updated Z80 decompressor by Antonio Villena.
Miscellaneous bug fixes.

(download removed)

2019-01-05: Exomizer v3.0.2 released

Changes since the 3.0.1 release:

Add documentation about level, mem and raw outfile structure.
Fix raw -d -r combination to reverse the inbuffer before decrunch.
Fix -P0 literal sequences bug in exodec.c, Bug reported by Nino Porcino.
improved cruncher tuning for slightly better compression on average.
Added sfx support for a new target, BBC Micro B (-t 0xbbcb).
Added -P+16 awareness to exodecrunch.s
Fix bucket optimization to be -T+4 aware in search.c, Bug eported by Ciccioriccio.
Fix absolute offset overflow bug in sfxdecr.s. Bug reported by Comos.

A complete changelog is included in the zip file. Download it here.

2018-08-10: Exomizer v3.0.1 released

Changes since the 3.0.0 release:

Added missing clc to 6502 decrunchers (sfx and exodecrunch.s). This made decrunch fail if the decruncher was entered with the carry flag set. Bug reported by soci.

(download removed)

2018-05-16: Exomizer v3.0.0 released

Changes since the 2.0.x releases:

Faster 6502 decrunchers (sfx and exodecrunch.s). Up to almost 50% faster than 2.0.11 if you are willing to trade some size for speed. To facilitate this the default bitstream format has changed. See exo30info.txt for details and benchmarks.
Very slightly improved compression for some files.

(download removed)

2018-03-08: Exomizer v2.0.11 released

Changes since the 2.0.10 release:

Now supports the Applesingle file format for reading. It is also written by sfx when the Apple ][+ target is selected. The Applesingle format is also supported by cc65 2.17 and AppleCommander 1.4.0 beta. This change was suggested by Oliver Schmidt.
The sfx sub command recognises a new string "bin" as a shortcut for setting i_load_addr and run addr to the load addr of the in file.
The sfx sub command is now for some situations able to autodetect the target for sfx bin and sfx <addr> by looking at the format of the in-files. The auto detection will succeed if the formats are non conflicting and one of xex, Oric tap or Applesingle (optionally combined with raw files).
Fixed hard to trigger compression iteration crashing bug caused by the thread safety changes for library compilation introduced in 2.0.10, reported by Lasse Öörni.

A complete changelog is included in the zip file. Download it here.