Inmos B004

I’d call the Inmos B004 the “mother of all Interface cards”, simply because it was the first ISA card sold by INMOS. And it wasn’t just the card but it also defined the (PC) standard of the software interface, mostly called the “B004-interface”. What a surprise 😉

So being the first card, it is quite big (full ISA length) while not offering really impressing specs: 8bit XT Bus, just one Transputer –TRAMs weren’t invented yet- and a max. of 2MB RAM (DILs). To do it justice, the manual rightfully calls it “Evaluation Board” and for that purpose it’s totally fine – remember that 2MB were quite an amount of RAM back in 1984.
To create a multi-Transputer network you had to either plug-in multiple B004s or connect an external network to the onboard connectors (the blue ones in the picture below).

As mentioned, the B004 software interface is what makes this card a keystone in the Transputer universe. All communication to the host (i.e. the XT/AT compatible PC) is done through a port range normally beginning at 0x150 (base, can be moved by some cards).
With certain offsets the host software can communicate with the Transputer, or the C011 to be precise:

Base Address Register Comment
+0x00 C011/12 input data  read
+0x01 C011/12 Output data write
+0x02 C011/12 input status register read = returns input status
write = set input interrupt on/off
+0x03 C011/12 Output status register read = returns output status
write = set output interrupt on/off
+0x10 Reset/Error register write: Reset Transputer & C011/12 and possibly subsystem (check manual)
read: Get Error status
+0x11 Analyse register  (un)set analyse

This mapping was used by more or less all ISA interface cards and extended by other more sophisticated interface cards later.

Clones

Needless to say, that very soon there were a couple of “inspired” models from other manufacturers. AFAIK all of them support Transputers up to 30MHz, which the B004 didn’t… so they’re actually better.

This example is from Microway (yes, those guys who later build the i860 Number Smasher), named Monoputer and dated 1987. Up to 2MB could be used on it. Mind the connectors being accessible from the outside:

Microway-B004

Later they produced the “Monoputer 2” which was more modern and used SIMM RAM modules instead of DIL parts. The Transputer and Linkinterface moved into the middle of the card and the link connectors were moved inside the pc case again – the connectors are the very same used on the NumberSmasher860:

monoputer2

And here’s the one Transtech made, calling it TMB04 mind the SIMM banks which enable the card to give home up to 16MB RAM (at 3 cycle speed!):

Transtech TMB04

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