This EPROM cartridge board has 4 EPROM sockets for a 27C256 EPROM each, making it possible to fill the full 128kB cartridge space.

Two sockets are for the ROM4 area (0xFA0000 to 0xFAFFFF), and two sockets are for the ROM3 area (0xFB0000 to 0xFBFFFF).

Both ROM areas have a socket for the high byte and the low byte part of the ROM.

If only a part of the address space is needed it is also possible to just populate parts of the board, for example only the high and low ROM4 EPROMs are needed for the Atari ST and STE diagnostics software.

Note: The components are on the bottom side of the board, and need to face down when the cartridge is in the slot.

A 3d-printable case for the cartridge can be found at: https://www.thingiverse.com/thing:6041939

The cartridge should also work on Mega, Stacy, TT, and Falcon computers, this however was not tested.