The Multitech MPF-1

The MPF-1, or "Micro-professor" was introduced in 1981 for educational purposes by MultiTech Industrial Corp. This later became Acer.

There are several computers having "MPF-1" in the name:

MPF-1 (later called MPF-1A)
The original Z-80 machine with a 2 kByte monitor ROM and a six digit 7-segment display.
Identical to the MPF-1A, but with the Tiny-Basic included. The original 2k Byte ROM was replaced by a 4k Byte ROM, which contained both the monitor and Basic
A reissue of the 1B, but with a better keyboard and a 20 character 14-segment display.
A 6502 computer using an external video. More related to the MPF-II than the other 1s.
A 8088 computer using a 2 lines by 20 character LCD display. This one had a real case and a real size keyboard.

Board in book-type package MPF-1
 in cover This is my MPF-1 in its package. There are some enhancements visible:
  • The board with wires on the right was made to test software and hardware extensions. Of course those never materialized.
  • In the extra RAM/EPROM socket is a battery backupped RAM board.
  • Above the voltage regulator is a small fan. The heatsink becomes uncomfortably hot without.
Printer PRT-MPF Microprofessor MPF-1B printer
Speech Module SSB-MPF Microprofessor MPF-1B speech processor The speech synthesis module is based on the Texas Instruments TMS5200NL chip.
Video-MPF-1 Microprofessor MPF-1B video card
character set of the VID-MPF-1B
There are at least two versions of this board; the original with the EPROM at 0800h-0FFFh and RAM at 3000h-37FFh, and a newer version with EPROM at A000h-A7FFh and RAM at 4000h-47FFh. For the original version the monitor ROM on the MPF-1 was exchanged by a combined monitor (0000-07FFh) / VIDMON ROM (0800-0FFFh). But the later MPF-1B had a monitor / Tiny-Basic ROM. So the VIDMON ROM was relocated to A000h-A7FFh.

Useful routines for version 2.0:

  • A001h - ?
  • A004h - init 6845, clear screen, return from call
  • A007h - init 6845, clear screen, jump to 0000h
  • A00Ah - (JCRTCO) print character in C, interpret control codes
  • A00Dh - (JCRTOU) print character in C, print codes 00h-31h too
  • A010h - (JTEXCO) print 00h terminated string (start in IY)
  • A013h - (JTEX??) print 00h terminated string (start in IY) CR = LF
  • A016h - writes character set to screen
  • A019h - configure 6845 with register/data table in HL (FFh terminated)

The character set image is the result of the key sequence: [ADDR], A, 0, 0, 7, [GO], [ADDR], A, 0, 1, 6, [GO].

The 2.0 ROM has a deliberate routine to replace every printed [`afg by afhi^. Why is a mystery to me.

The manual for version 1.0 is at the Virtual library. A modified ROM is also available here fixing the character mangling.

Local links:

External links:


Last update: 2015-02-23