odd Exorbus 6800 AMF boards

Most recent revision date of this page, June 20 2022. Copyright 2022 Herb Johnson except for content owned by others who own their own content, notibly Neil Cherry.


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. Neil's dump of the ROMs reveals these are likely AMF Inc board to control bowling alley equipment; a patent explains their general operation. On another Web page, I show some more ExorBus class 6800 6809 boards. An EXORset system and description of EXORbus is at t this link.- Herb Johnson


MPU boards

[odd exorbus]

These two boards are marked "MPU". but it has a 6800 associated with a 6820 (parallel chip). And, the parallel chip is wired to the bus. Odd. There's some 2112 4 X something RAMs, a TI 2532 ROMs.

Theory: this board is some kind of I/O controller, and the I/O is taken off pins on the bus. Maybe each board controls something on each slot?

[odd exorbus]

This board is identical to the above. But it has some custom ROMs made by Motorola. They are marked "AMF1176-78" or "-70". -Herb

yy MPU board

[odd exorbus]

This board is marked "yy MPU". Clearly different from the "MPU" board above, it looks like it may be a bus controller. There's a 6800 on board, some sockets might be bytewide ROM or RAM. There's a 6850 (UART) next to the 6800.

There's an etch "yy MPU 92-226-001-229" on the board. A date stamp is 9-15-82. A label is "BCC system". There's an edge connector on top, with a small PC board with 8-pin DIPs. Could be, a pair of optoisolators for a serial current loop? There's a label "10.49 MHZ", probably the clock frequency.

Signal tracing of the edge connector of this board, will confirm if it drives the address lines to ExorBus standards or not. - Herb

ROM board

[odd exorbus]

This board is marked "ROM". Certainly it's full of TI TMS2516 ROMs. Those specific brand and part number are TI's product for "2716 compatible" EPROMs. It's confusing but TI's first "2716" was an early variation of 2708's. When other companies standarized on 5-volt-only 2716's, TI had to call their "standard version" a 2516. I hope I have that straight! ;) But there's also a National MM2716Q on the board, so that confirms the standard.

The board has a date stamp of 8-24-82, probably when it was tested or updated. A board part number is "82-226001-282". There's an etch "BROM",

RAM board

[odd exorbus]

This board is marked "RAM". Certainly it's full of AM9124 static RAMs.

Inspection of the boards

Neil, June 20 2022: Things are getting interesting, not sure if good or bad. From the main CPU (with the 6850 UART on it). I see [from the ROMs in the ROM board?} "BOWLER'S CONTROL CONSOLE - VERSION" and "MANAGER'S CONTROL CONSOLE - VERSION"

So the read of the main CPU roms looks good. It also mentions lanes, scores. The PROMs and boards have AMF on them. AMF made a lot of bowling control equipment (thus the lanes and ...).

I read the 'MPU' roms and the 2532 doesn't read correctly The last 6 addresses read:

b7 60 04 6f 0d 6f 01 96
b7 60
04 6f
0d 6f
01 96

None of those fall in the address space of the ROM (2732 = 4K Fxxx). I'll need to check the board to see if the address lines are inverted or something. I think one German company did that (what a mess working on those boards). {I suggested to Neil, he confirm he's reading a 2532 and not a 2732, and check the speed rating. - Herb]

The second MPU board's ROMs can't be read or are bad. [They are Motorola marked with "AMF".]These ROMs are special Motorola masked ROMS (or the special one shot ROMs). Those can have weird control lines. I need to check if the select lines are different from normal ROMs.

AMF's patents explain

Web search for AMF bowling control equipment, led to a number of patent applications by AMF in the late 70's through the 1990's in regard to bowling lane equipment. A US patent 4302010 stood out as descriptive of this 6800-based hardware. Below is the beginning of that patent, and here's the PDF of the patent as available from Google's patent image archives among other patent sources. Web and patent search for the inventor, Reginald A. Kaenel, shows he received over 50 patents assigned to AMF, Western Electric, AT&T; on magnetic and electronic circuits, bowling electronics among others. He apparently passed away in 2017.

Here's a text document of the patent that describes the 6800 hardware and software system in patent-language detail. There may be a source listing in a prior application for patent, but that's not available online. - Herb

United States Patent  4,302,010 
Kaenel Nov. 24, 1981 
Inventor:  Reginald A. Kaenel, Weston, Conn.  
Assignee:  AMF Incorporated, White Plains, N.Y.  
Appl. No.:  42,380  
Filed:  May 24, 1979 
date of patent: NOv 24 1981


An automatic bowling scoring system is disclosed including a central manager's console unit linked in parallel over a plurality of communication buses with a plurality of lane score processors having printing and CRT display monitor units. The manager's console sends commands to the score processors, and thereby gains control over the execution sequences followed by this score processor and modifies its functional sequence. In particular, the manager's console is capable of selectivity controlling the display at any lane pair processor, to cause display of locally generated game score information, or supplementary information developed at the manager's console. The manager's console can also cause the transfer of the locally generated game score information appearing on any monitor to be routed over the buses to the manager's console display monitor. 

What is ExorBus?

ExorBus was the bus developed by Motorola for their 6800 and 6809 processor development systems and single-board computers. This text document shows ExorBus signals for two Motorola cards.

So are these boards ExorBus? The minimal consideration is to follow the power leads. The ExorBus signals show multiple pins at either end of the buss connector for ground and +5 volts. Inspection of these board images, show the same pins at either end are commoned together.

Herb Johnson
New Jersey, USA
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