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Kearney & Trecker PDP-8/A board set documentation needed

BitWiz

BitWiz

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I received a set of Kearny & Trecker CNC Machine control boards my recent PDP-8/A acquisition.

I'm looking for any documentation on these boards.

It consists of the following boards:

1-20168-06 96K x 8 Memory Board (hex wide but no connections on the extra edge connectors)
1-20668 Hard Disk Controller for SA4004 or SA4008 drive (hex wide board but only quad edge connectors)
1-20641 Analog Interface this board has industrial type connectors on the top (hex wide board but only quad edge connectors)
1-20640 This board has 4 forty pin dual inline berg type connectors on the top (hex wide board but only quad edge connectors)
1-22205 This board has a MC6809, 128K x 8 dynamic memory, 3 6850 ACIA serial chips, and several off board connectors (hex wide board but only quad edge connectors)
1-20661 Feedback Subsystem This board has industrial type connectors on the top. (hex wide board but only quad edge connectors)

Thank you.
 
Found some of the disk controller on eBay. It was interesting to what it looks like, seems to be all SSI/MSI TTL, no LSI disk controller chip.

I didn’t find any documentation though. I’m sure you already searched.

Use of the MC6809 was entertaining. Kind of rivals the compute power of the thing it’s plugged into. 😀
 
A MC68B09 or a HT63C09 would easily out perform a PDP-8/A.

2MHz (68B09) or 3MHz (63C09), 3 Interrupts (IRQ, FIRQ & NMI, vectored even), 64K Address space (up to 1MB with Dynamic Address Translation), 2 8-bit accumulators (can be concatenated into 1 16-bit accumulator), 2 16-bit index registers, 2 16-stack pointers that can also be used as index registers, auto incrementing index & stack registers, long and short branches, full position relative code, etc.

The 6809 is the best 8-Bitter ever designed and the 2nd best micro ever behind the 68000 family. In my not so humble opinion 😎

If you would like any pics let me know.
 
While off topic, comparing performance of different architectures is always entertaining and never cut and dried easy. If the 8/a is equipped with the FPP-8 and you are running FORTRAN on both machines I suspect the 8/a would be quite a lot faster. If equipped with a KK8E CPU with EAE it is probably several times faster at large math.

Memory bandwidth using DMA devices is 10 mbps on the KK8E omnibus. The 500ns memory cycle with 8 bit bytes gives the 6809 memory a 16 mbps bandwidth. But that doesn't have anything to do with the CPU performance. Which would I rather write a compiler for? No question, the 6809.
 
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