Motorola EXORmacs Development System

The EXORmacs is a Motorola 68000 based software and hardware development system that first shipped in January of 1980. The backplane that interconnects the boards is VERSAbus, and predecessor to VMEbus. It normally runs the VERSAdos operating system, but can also run CP/M 68k or the SYSTEM V/68 version of UNIX. There were a large number of accessories available for the system for software and hardware development.

The system powers up OK, and displays an error related to not being able to boot because there are no disk drives connected.

The EXORmacs was designed by a team of Motorola engineers led by Jack Kister. John Black joined the development team soon after the EXORmacs was introduced. John found that the VERSAbus documentation was not sufficient to guarantee interoperability between different vendors boards. John rewrote and updated the documentation several times, and was part of the team that developed new VERSAmodules.

VERSAbus was eventually moved to the Euroboard mechanical format using DIN C96 connectors and became the very popular VMEbus.

We need to find out what diskette drives and SMD disk drives will work with this system in order to get VERSAdos running.


Some of the system is alive!

With some switch twiddling we were able to get the onboard Motorola Advanced Computer Systems Debugger running. The MACSbug debugger was also available for the Apple Macintosh.

MACSbug 2.3

PC=00000000 SR=2700=.S7..... US=FFFFFFFF SS=00FEF9A6

D0=00001400 D1=0000FF00 D2=0000FFFF D3=00000000

D4=00FE9800 D5=00000000 D6=00000008 D7=00000041

A0=00FEE011 A1=00FE9856 A2=00FEF854 A3=00FEF9AE

A4=00FE989C A5=00FEFF00 A6=00FEFF00 A7=00FEF9A6



Slot A1 is the EXORmacs Console Interface and holds EPROMs that contain the MACSbug code.

Slot A2 is a M68KMPU CPU with an 8 MHz 68000 CPU chip, 2x serial ports, 1x printer port, and 1x floppy disk drive port.

Slot A4 is a M68KVM11-2 512k Byte RAM

Slots A6 & A7 are M68KVM21 Disk Interface Module and a M68KVM21 Universal Intelligent Peripheral Controller.

Slot A12 is likely a M68KVM30 Multi-Channel Communications Module that provides four additional serial ports.

The connectors on the back panel go to the serial console terminal, printer, 8" floppy diskette drives, and SMD disk drives.

Motorola M68KMPU CPU

This CPU board has an 8 MHz 68000 32-bit CPU chip that has a 16-bit bus interface. It has 3x EPROM sockets that contain the bootstrap code. It also has 2x serial ports with a maximum speed of 19,200 baud, and 4x parallel ports.

Motorola EXORmacs Console Interface

This board connects to the buttons, lights, and 7-segment display on the front of the EXORmacs system. The onboard EPROMs contain the MACSbug code.

Motorola M68KVM11-2 512k Byte RAM

The board uses Mostek 65536 x 1-Bit DRAM to support 256k x 16-bit memory plus extra bits for EDAC (Error Detection and Correction). If two boards are installed, their addresses can be interleaved to improve the CPU AND DMA performance.

Motorola M68KVM30 Multi-Channel Communications Module

This board provides 4x channels of 9600 baud synchronous or asynchronous serial communications and 1x Centronics parallel printer port. It has an onboard 6801 CPU with firmware in EPROM, 4x MC2661 EPCI chips for serial, and 1x MC6821 PIO chip for parallel.

Motorola M68KVM21 Disk Interface Module

This is the DIM part of the two board DIM/UIPC board set that is the disk/diskette controller. This board does not connect to the VERSAbus and provides the support for 2x SMD/CMD/MMD/LMD hard disks and 4x floppy diskette drives. There is a 50-pin ribbon cable interconnecting the DIM and UIPC.

Motorola M68KVM21 Universal Intelligent Peripheral Controller

This is the UIPC part of the two board DIM/UIPC board set that is the disk/diskette controller. The onboard MC68120 IPC has 128k of dual-port DRAM, 4k of static RAM, and 4x EPROMs containing the onboard firmware. There is a 50-pin ribbon cable interconnecting the DIM and UIPC.