Turbo Imploder reduces the disk space used by Amiga executable programs. Starting a packed program restores its contents in memory before handing over control.
The original 4.0 documentation credits Albert-Jan Brouwer and Peter Struijk with programming, Paul van der Valk with music programming and composition, and Erwin Zwart with graphics and layout. Its Authors file explicitly distinguishes freely distributable software from public-domain software. Fred Fish’s disks helped circulate the package; Fish’s 1994 announcement lists version 4.0 on disk 984.
A program has several pieces
An Amiga executable contains hunks: sections for code, initialised data and space reserved for working data. Some need Chip RAM, which custom hardware can access. Addresses inside those sections may also need adjustment when the program is loaded.
The Techno document explains how Imploder reconstructs that arrangement. AmigaDOS’s loader allocates the destination hunks. The packed data, decompression code and a temporary buffer accompany them; unpacking fills the appropriate sections and processes relocation information. Temporary sections are released afterwards.
A smaller disk file therefore does not mean a smaller memory requirement at every moment. During expansion, packed input, working space and the restored program must coexist.
Executables and data need different tools
The AMCAF extension manual separately documents File Imploder, supplied with the Turbo Imploder 4.0 package. It lets a program load or unpack compressed data banks and recognises their IMP! marker. That is a related tool, distinct from the executable packer’s job of rebuilding a runnable program.
AMCAF also supports PowerPacker, showing how applications could read more than one packed format. In both cases, saving bytes on disk depended on having the appropriate decoder where those bytes were used.
Imploder’s documentation warns that preprocessing can remove debugging material and change the load-file representation. Recovering a runnable program is not the same as recovering the exact original distribution file. Its authors consequently advised keeping the original archives and disks.
Sources
- Albert-Jan Brouwer and Peter Struijk, Imploder 4.0 documentation: Original version 4.0 Authors, Introduction, Techno, Philosophy and Library files; credits, memory layout and reversibility.
- AMCAF Extension 1.40 manual, Packer Support: Independent AMOS extension manual, Packer Support; File Imploder and its IMP! data format.
- Fred Fish, Contents of disks 976–1000: Original distribution announcement, 17 May 1994; disk 984 lists Imploder 4.0 and four contributors.