Info from HESS Duane: Shows the top cover off. Note the PCB on the TELPAR printer seems to have much more circuitry. There are 3 daughter boards installed in the center, in front of the colored cables from the printer & Program ROM cartridge slot. To the right is an empty daughter board slot in front of the cassette cable (black sheath). The left 2 positions is program memory and the right 2 is data memory. The daughter cards use the dual-density HD3546 chips. The motherboard natively has 1000 program steps and 100 memories. So the unit you see has 3000 program steps and 200 memories. The daughter cards are identical and you can install them where-ever you choose. So max. internal is 3000 program steps and 300 memories. The number stamped on the daughter cards is EHI-033-02. Other chip on the card is either a MOTOROLA 7730 or 7628 MMH0026PCI.