Source: MPF-I Users's Manual SSB-MPF Speech Synthesizer Board Operation Manual PRT-MPF Printer Operation Manual Video-MPF-1 Beschreibung VIDEO fuer Micro-Professor MPF-1 Address space ------------- 0000 Monitor ROM 07FF 0800 Tiny Basic (MPF-1B) or VIDMON ROM (original) 0FFF 1000 free 17FF 1800 U8 RAM 1FFF 2000 U7 RAM / EPROM 2FFF 3000 Video RAM 37FF 3800 Copy Video RAM 3FFF 4000 RAM / EPROM Video card (2k, VIDMON 2.0?) 4FFF 5000 SSB-MPF ROM 5FFF 6000 PRT-MPF Monitor ROM, SSB-MPF Expansion ROM 6FFF 7000 Expansion ROM SSB-MPF, PRT-MPF 7FFF A000h VIDMON 2.0 ROM(*) A7FFh I/O space (port decoding is very incomplete, the whole range 00h-BFh is occupied by PPI, CTC and PIO!) --------- 00 8255; A, B, C, Control 03 40 Z80 CTC; 0, 1, 2, 3 43 60 IOM-MPF 8251 (for the MPF-1P?) 61 64 IOM-MPF CTC (for the MPF-1P?) 67 70 EPB-MPF-1BP 8255 (will not work with the 1P with CTC installed) 7F 80 Z80 PIO; DA, DB, CA, CB 83 CA, CB PRT-MPF CC-CF EPB-MPF-1BP 8255 FE SSB-MPF F0 Video card 6845 registers FF ------------------- *) he Vidmon2.0 ROM accesses several addresses in the 0ff04h - 0ffcch region. My board has no RAM there, so it might not be required. Maybe it is for some debug device?