The bed of nails could be used in place of a C004 for another reason – it would need a piece of code to configure it. Replacing it with fixed wiring saves that – as the other extra board is an RS422 driver and the unused TRAM sockets have a link hardwired through, I would guess that this board was used in some sort of test setup as the simplest and cheapest way to drive some remote(ish) transputers from a PC. If there were no TRAMs with transputers on the board, then this board would simply have been a link adapter (can’t remember the part number) mapped into the memory space of the PC then driving via RS422. As such, someone may have been using it without transputers at all – just as a means of getting a nice simple high speed serial link for some sort of one off piece of kit. In that case, an RS422 connected to another link adapter may have been all that was at the other end – or they used RS422 then connected to a TRAM and so that all the transputers were in the remote kit and this was simply a cheap way of booting them over a reasonable distance.
They may have removed the C004 from the B008 socket and used it in their own kit at the other end.
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Dear Larry, Tony
The "Bed of Nails" is a C004 32-port crossbar switch whose data sheet (including pinout) you can find at:
Not everyone wanted a C004, and it's possible that, at the time we designed the B008, the C004 was not in production, so the 84-pin array was a way for users to construct their own link network without having to bother with configuring the C004.
Lifting the pin array should not cause any damage, but I don't think you will see very much underneath it.
On 20/11/2017 17:54, Lawrence Dickson wrote: