Motorola 6800 6809 EXORbus-based systems

Most recent revision date of this page, June 19 2022, link added Mar 25 2024. Copyright 2024 Herb Johnson except content as provided by the authors noted. These are discussions and content about 6800 and 6809 systems based on the EXORbus, like the Exorset 30 system I have Content available and correspondence quoted with permission, thanks! Look at all my 6800/6809 work on another Web page of Web links. - Herb.

Stan Ruppert

[exorset] [exorset]

Stan Ruppert contacted me on July 29-30 2019 as follows:

I'm working to restore two Matrox brand graphics cards ( exo-2480 and exo -512 ) These are the Motorola exorciser system versions ( 86 pin bus ) of the s-100 alt-2480 and alt-512 cards. Hoping to add graphics to my vintage exorciser systems. I'd like to pick up some clues about their circuit design philosophy from the S-100 Matrox ALT-512 manual you have. Google searching led me to your S-100 site. [I supplied him with a ALT-512 S-100 manual. - Herb]

I've sent photos of my EXO 2480 and EXO 512 boards. Looks like 90

of the layout is similar between the S100 and Exorciser versions. At first glance, only the bus interface section and removed voltage regulators looks to be different.

Looks like your Exorset 30 is a terrific and quite capable system. That's a system I haven't actually had the pleasure of using. Love how it is an all in one with screen, keyboard, and cage for cards.

The 6800 Exorciser system I mainly use is indeed the first version Motorola released for the 6800. One heavy beast of a chassis. It's the system documented [at]. [Later Ruppert said he found documents at as well.]


The disk system that goes with it is also first version of the EXORdisk - using the Pertec FD400 drives in an FC360-2 enclosure. [Here's a photo of the controller board.] The controller has the boot code in bipolar prom specific for the Pertec drives. The controller uses the 6852 for IO. The MEX68DB card has the MAID monitor code that then calls the boot code on the controller card when booting XDOS or MDOS.

Most other systems I've seen are later versions, using the second rev of the floppy controller 68FDC2 - documented on bitsavers and other vendor floppy drives. Haven't found much info other than brochures for the older controller and had to try and reverse engineer the schematic from the board. [Later he found the manual. - Herb]

I've been using and enjoying exorciser based systems ever since high school in the mid seventies. A relative gave me a 6800D2 kit to experiment with - and it sparked my interest and led to a career in engineering and science. I just recently restored my original D2 system; amazed I could find all the boards and my original notes stashed here and there through many moves. [I discuss a D2 on another Web page. - Herb]

[It became] quite a Frankenstein system in the end - with IO boards enabling use of S100 memory cards and Wintek 12K Basic and Wintek Fantom Monitor and an electronic systems TV typewriter board with custom UART circuit for keyboard. I had also pried the lid off of an early 1K dram chip back then and used it's light sensitivity on the 32x32 die as a crude telescope control / guidance system. Cool proof of concept. Learned an incredible amount amount electronics as a kid (nerd) experimenting with it.

I've restored a variety of Exorciser based boards, SWTPC stuff, and later Motorola dev kits since then - including math coprocessor cards, IO/control cards, A/D cards, even a magnetic core memory card - Love ferrite cores! And now the Matrox cards for graphics.

Have several systems running for my continued 6800/09 code development and I use some of them to digitize signals from various earthquake sensors (my day job is earthquake research and engineering). Fun to combine the profession and hobby. Amazing how at work I think nothing of the petabytes of data we store and analyze when it all began with kilobytes on my 8 bit systems.

Regarding the ALT-256/512 cards, Hugo Holden just posted a draft whitepaper he wrote on restoring his 256 and 512 cards. Great read if you haven't seen it yet.

Your site has been a great reference - I appreciate all the time you've put into documenting and sharing your experiences with other enthusiasts. The historical and technical restoration information has been super informative on many projects.

- [regards] Stan Ruppert

Neil Cherry and various ExorBus boards

Creative Micro Systems CMS

My friend and technical colleage Neil Cherry was working on some Exorbus boards and contacted me on Oct 2019. He found a Web blog about some Creative Micro Systems CMS 6809 hardware. It's linked to a github site of CMS ROM disassemblies and some bits of documentation for the CMS 9639 and 9642 boards. Here's his 9609 CPU board. These are EXORbus compatible cards apparently used for industrial controls. Neil may have some documents for a MIKUL 6809-5, another brand of EXORbus industrial controller. Here's some correspondence I have from Neil. - Herb


Here's what I have found [from Web search] the debug roms for the CMS boards. Very useful but I've not dug into them deeply yet. That should be useful for running the CMS 9609 board I have.

While reading about the 9639 (I don't have this one but do have the PDF), I found that it has 2K of DAT (6116 RAM used as Data Address Translation). The 9609 has an odd setup for RAM, it has a 6116 (2K) and 2x2114. That makes no sense, but I opine that it is the DAT RAM. It's not quite the same as the CMS 9639 but if I were to engineer something like this. My later designs would be based on earlier ones and many good engineers follow a similar pattern. If I can get this set of boards working I think I'll have a rather unique example of a commercial/industrial computer from the pre-ibm PC days.

Motorola Micromodule


[Photo of the Motorola M68MM19 6809 Micromodule]

I have spent so time putting my parts orders in for my 2 Corsham Tech SWTPC 6809 replica [CPU boards]. I'll order more parts next month and work on adding what I have over the next few weeks.

I did get some information on the Exor bus. I'll compare it to the schematics you provided. I'll then post that up on my web site. - Neil

Mikul Exorbus products


Neil Cherry has a Mikul 6809-5 board, that Neil is working on. He says: "The MIKUL board is a terminal board. It has a 6809 (MPU), a 6847 (Video), a 6116 (SRAM), 6821 (PIA) and a Z80 SIO. No space for ROM or extra RAM so it expects that to be on the bus. Not sure how I can run both the terminal and the MPU boards in the same bus (probably can't) but I'm still thinking about it. Probably won't get further than that. ;-)"

From some industrial sources, I extracted the following information. - Herb

The 6809-5 was a "standard product board" that has an operator interface consisting of an encoder for a 20 key keyboard matrix, and a 16x32 character monochrome composite video CRT display driven by the 6847 and the 2K static ram display buffer. It also has a proprietary transformer-isolated industrial network interface using the SIO. The 6809-5 has no on-board ram or prom memory.

The Mikul 600 Series boards were designed for industrial applications, and had 6800 or 6809 processors. Motorola ExorBus compatible cards, the Mikul 6000 series, followed, mostly with 6809 processors. Eventually there were some 68000 VME cards, the Mikul 1600 series.

The Mikul 6809-5 board was used in a heat treating furnace control for a furnace OEM. The control managed the temperature and atmosphere in the furnace and some of the automation related to moving product in and out of the furnace. The operator interface consisted of a keyboard matrix interfaced to the PIA,  and a CRT display (driven by the 6847 and the static ram). It had TL's proprietary transformer-isolated industrial network interface, (SIO, some logic gates and the 2 red transformers at the top of the board) to support statistical process control.

There were a couple other boards in the system with analog I/O (A/Ds, D/As, 6840 timers), and memory (ram, prom and EEROM). The control cabinet was beside the furnace, a pretty hot, dirty place.

more odd Exorbus boards

In June 2022, my colleague Neil Cherry obtained a set of boards which appear to be ExorBus format, with 6800 processor-family chips on them. He and I are trying to sort out what these are and where they were produced. I cobbled up a Web page, to gather and solicit information about them. - Herb

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