Multidesk 64

Multidesk 64 is a small brute force hack that was developed for the Oneload64 project, but is not limited to that. The idea for this is to combine several MagicDesk cartridges into one Multi-Cart. This is, of course, impossible.

The MagicDesk format is a simple and effective bank-switching cartridge. It shows up in the memory space of $8000 to $9FFF and a simple write into $DE00 switches into that bank. There is no protection against switching into no-existant banks and there is no way to find out which bank is currently active, as reads from $DE00 will make uncontrollable bank switches. It is a bare-bones as it gets. Oh, and writing a value higher than $7F will switch the cart off (you can get it back with a lower value write). This gives you 64 banks of 8K each.

Because of its simplicity, the format has been adapted by several projects to create fast starting games for emulators. The three main projects are:

• OneLoad64 with literally thousands of games in MagicDesk format
• MagicDesk CRT Linker which allows to convert VICE freezes into cartridges
• T64 to CRT, my own project to convert tape-based software into cartridges

Most C64 games just load once and then never need to access a disk or tape. Many C64 games require constant loading of parts from disc or tape. And then there are some C64 games that consist of several parts which the user most load themselves. Sometimes the two sides of a tape have different versions of a game, sometimes you need to play through Part 1, receive a password, manually load Part 2 and then type in that password to continue. Those games so far were also split into several cartridges in the OneLoad collection and I wanted to change that.