Magic Desk 2 is an ambitious hardware project by crystalct, which aims to create a 3-in-1 Commodore 64 cartridge. This cartridge builds upon the concept of the Magic Desk 1MB and Universal c64 Cartridge designed by Marko Šolajić and is able to accommodate up to 2MB ROM due to new advancements in chip technology like 27c160 EPROMs. These chips are cheaper and more available than ever before, allowing for assembly with Through-Hole Technology (THT).

3 Different configurations

  • Magic Desk 16Kbyte config
  • Double Magic Desk 1MB
  • GMod3 2MB Read Only cartridge

Magic Desk 16Kbyte config

Old Magic Desk Cartridge could be:

  • Standard [32Kb (4 banks), 64Kb (8 banks) and 128Kb (16 banks)]
  • DDI Magic Cart [32 banks, 256kb]
  • Magic Desk Clone homebrew cart [64 banks, 512kb, and 128banks, 1MB]


  • ROM is always mapped in at $8000-$9FFF (8k game)
  • 1 register at IO1 / $DE00
    • bit 0-6 bank number
    • bit 7 EXROM (1 = cart disabled)

Magic Desk 16Kbyte config

  • supports all “Magic Desk Clone” homebrew cart with 16k game config, up to 2 MB
  • ROM is always mapped in at $8000-$BFFF (16k game)
  • 1 register at IO1 / $DE00
    • bit 0-6 bank number
    • bit 7 EXROM (1 = cart disabled)

So, 128 banks and one bank is 16Kbyte: 2MByte of ROM space.

Double Magic Desk 1MB

You can put 2 different 1MByte bin images inside 27C160 EPROM (from $000000 to $0FFFFF and from $100000 to $1FFFFF) and select them using SWCOMP1 (or JP1) switch like 2 different sides of a magnetic tape data storage.
Bin files can be made using Magic Desk Cartridge Generator, as usual.

GMod3 2MB Read Only cartridge

You can configure this cartridge to partially follow the functional specifications of the GMod3 (Individual Computers) cartridge type:

  • 2MB of ROM space
  • ROM is always mapped in at $8000-$9FFF (8k game)
  • No Write capability
  • Register at IO1 / $DE00
    • bit 0-7 bank number (256 banks)
  • Register at $DE08
    • bit 6 EXROM (1 = cart disabled)
  • No bitbang mode

You can use the new Magic Cartridge Generator (by Žarko Živanov) to make 2Mbyte GMod3 bin images of games compilation.

To learn more and get your own Magic Desk 2 click here to visit crystalct’s GitHub page.

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