This Cartridge PCB uses only one ROM from HITACHI named HN613256P. This chip is a CMOS Mask Programmable Read Only Memory, designed especially for use in a bus-organized systems.

Its built in memory matrix has 32,768 x 8bit word, which means 32 Kbytes of data available. It has an address decoder which interfaces directly to the computer through cartridge connector and a 3-State Output Buffer for data output which is driven by two signals by the computer.