Short: Generator of a valid digital signature for an Atari 7800 cartridge Author: Bruce Tomlin. Amiga port by Wojciech Pasiecznik/Voy/SSG^Dial^SWAT Uploader: Wojciech Pasiecznik/Voy/SSG^Dial^SWAT (voydial wp pl) Type: util/crypt Version: 1.0 Requires: MC68000+, ixemul.library Architecture: m68k-amigaos This program will generate a valid digital signature for an Atari 7800 cartridge ROM image. The code was created by hand-decompiling the original 7800 encryption program for the Atari ST into plain C code, so it does not rely on any external libraries and should compile for almost any operating system with no muss and no fuss. To run it: ========== sign7800 -t filename to test for a valid existing signature only sign7800 filename to generate a signature printed to stdout sign7800 -w filename to generate a signature and update the image 'Filename' is the name of the file with the cartridge data in it. It must be a binary file, with a size that is a multiple of 4K bytes. An extra 128 bytes is allowed, so that you can use it with a .A78 file. The '-t' option only tests to see if an existing signature is valid. The '-w' option causes the file to be updated with a new signature if it was not aready valid. A write will not happen if there is a problem with $FFF8, $FFF9, or the reset vector, or if there is already a valid signature in the file. Even with an already valid signature, a new signature is still computed and printed to stdout. WARNING: using the '-w' option should be safe if your file is really a 7800 cartridge image, but if it isn't, there is a possibility that data loss to the last 128 bytes of the file could occur! Be sure that you have a backup copy of or can re-create whatever file you use with the '-w' option!