Microcomputer system MC6800

The development of the the microcomputer system MC6800 started in late 1975 at the Institute of Electronics of the ETHZ by Dr. Rolf Zinniker, Dr. Kurt Mühlemann and myself. The system was based on the  8-bit microprocessor 6800 designed and first manufactured by Motorola in 1974.

The operation of the system was done with an external keyboard and an external oscilloscope display. Both units are connected with a parallel interface.

The system consist of the following elements:

  • a power unit with +5 Volt 6 Ampere, +15 Volt 1.6 Ampere and -15 Volt 1.6 Ampere
  • a microprocessor unit (MPU) with ROM (read-only memory); max 1 KByte
  • a memory board with RAM (random access memory); max 8 KByte
  • a peripheral interface adapter (PIA) to connect a keyboard
  • an asynchronous serial interface (ACIA) to connect a data recorder (tape recorder or floppy disk) or a printer
  • a parallel interface to connect the oscilloscope display

Several units have been build and were used in the electronic workshops for students. When I leaved the Institute of Electronics in march 1978, I received the prototype of the MC6800 system as a compensation for the numerous extra working hours which I spent in the microcomputer laboratory.

The following figures show the different units of the MC6800 system:

Power Unit

power-unit-4
power-unit-3
power-unit-2
power-unit-1
MPU
mpu-1
mpu-2
Memory 8KB RAM
memory-card-1
memory-card-2
PIA
pia-1
pia-2
Keyboard

ACIA

acia-1
acia-2

Display Interface

Light Pen



Documentation

ETH

Marco Barnig with the MC6800 MicroComputer in 1976 in Zurich

A german user guide can be downloaded as a pdf file.

Status

The +15V output of the Power Unit is faulty. The light pen has not been tested. The other units should work as expected.