T9000 Archives - GeekDot

As the T9000 had so many new features and architectural differences the “classic” TRAM wasn’t enough to support all that. So INMOS went to enhance the TRAM-model…

And they meant it! Instead of DIL 16 Pins of a “classic” TRAM, HTRAMs could use up to 160(!) pins to communicate to the outside world. Besides the classic 5V, also 3.3V was supplied on one pin as a tribute to the technical progress. Due to the introduction of the DS-Links (vs. OS-Links within the T4xx familiy), each of the four links of the T9000 now required 4 pins per link, resulting in 16 pins for the links alone. Plus many other special links for Events, ConfigUp/Down etc. a minimum of 60 pins were used.
Also each HTRAM now featured a PROM so it could be identified by software.

This is the pinout of an HTRAM extracted from the most recent source (SGS-Thomson B92x HTRAM datasheet, Nov. ’94)

Pin	Row a	Row b	Row c	Row d	Row g	Row h
1 2 3 4 5	ClkIn L0SIn L0DIn L0DOut L0SOut	N/C GND N/C V3V3 N/C	TDI V5V0 CupSIn GND CUpDIn	notTRST L2SOut L2DOut L2DIn L2SIn	EventIn0 EventIn1 EventIn2 EventIn3 –	EventOut0 EventOut1 EventOut2 EventOut3 –
9 10 11 12 13	L1SIn L1DIn L1DOut L1SOut Reset	N/C V5V0 N/C GND TMS	CUpDOut GND CUpSOut V3V3 TCK	L3SOut L3DOut L3DIn L3SIn V5V0
1 2 3 4 5	N/C N/C N/C N/C N/C	TDO GND CDnSOut V3V3 CDnDOut
9 10 11 12 13	N/C N/C N/C N/C N/C	CDnDIn V5V0 CDnSIn GND N/C

While many (i.e. 100) pins left unspecified in this pinout-map (e.g. Block 2 rows c & d, Block 3 rows e & f and the complete Block 4), they’re all used on the HTRAMs I own.
My guess is that those were used for the memory-bus, at least in the case of my Quintek board.

Here’s an original INMOS HTRAM, with a 15MHz T9000 engineering sample mounted, plus a T9000 (backside) next to it:

For a quickstart here are the 3 HTRAMs from Quintek which I own:

QT9A

The QT9A (Rev.C in this case) is a processor HTRAM of (yet) unknown clock-speed and memory-size – I think it’s 4MB. Because the T9000 ran really hot in the prototype stage (which he never left), all of them required a compariby big heat-sink. I do not dare to remove it, given the (collector) value.

…and the backside for completeness 😉

QT9H

This is a display HTRAM featureing a Bt485 RAMDAC, 2MB VRAM but no video-output part. The video signal is delivered to a pin-row which is going connected to a VGA-featurebus on a graphics card. It’s a Rev.C part, like the QT9A.

This and the following HTRAM were fitted into Slots 5 and 5 on the HTRAM-board which are quite special slots: They don’t offer the pin-blocks 1 & 2, i.e. no DS-Links etc.! That said they do feature fully populated pin-blocks 3 & 4 which underlines my assumption that those pins are meant for direct memory-mapping.
In the case of a Video & Encoding HTRAM this makes totally sense because it gives the Transputer even faster access to the Video-RAM than pumping all the data over the Links.
Which leaves yet-another-riddle-to-be-solved: Where are those HTRAM mapped into the T9000s memory?

…quite a lot is happening on the back-side, too:

QT9C

A video digitizing HTRAM using the BrookTree/Conexant Bt812 chip and having 2MB VRAM, too… this time “Rev.B”.

and the back side…

To be continued…

Again, Geekdot.com might be the only place left in the World Wide Web where you can get more information about the flopped mysterious T9000 than what you will find on Wikipedia.

The T9000 never made it into the market in higher volumes. I don’t have any numbers on how many T9000 were actually produced but only a few were evaluated outside INMOS by universities and science facilities, most famous is probably the CERN, which did some benchmarks and tests. Here’s a (now funny) promotion video of those days:

By another lucky incident I got myself a HTRAM mainboard for Christmas 2011. It’s the QT9M from Quintek, a spin-off of INMOS back then. Three slots of this 6-slot board were populated, one featuring the mythical T9000!

This is the naked board, the QT9M:

At the first look you can see it’s a damn huge thing. At least one inch taller than the slot-backplate. But this way Quintek could squeeze 6 size-1 HTRAM slots (3×2 slots, horizontally) onto the card, while the “official” INMOS B108 (PDF) board just features 2 slots (but size-4, vertically).

The HTRAM slots in detail

(-> For a complete description of HTRAM visit this chapter of geekdot.com)

Not all slots are offering the same features, though. Slot-0, slot 3 (the two middle ones) and slot-2 (lower left) offer the standard pin-blocks 1 and 2 as well as block 3 and 4.
slot-1 (top-left) offers the same pin-blocks but also a small 4×2 horizontally aligned block on its lower edge.
The same 4×2 pin-block can be found on HTRAM-slot 5 (upper right), but this time only the standard pin-blocks 3 and 4 are featured.
Finally, on slot-4 (lower right) only the standard pin-blocks 3 and 4 are featured, too, but it also has a 5×2 pin-block centred to the opposing edge of the standard pin-blocks.
My assumption is that pin-blocks 3 & 4 offer a direct connection into the T9000 memory map, so I’d call slot-4 & 5 “mem-mapped-ony slots”.

The interface logic

The interface logic on the board was kept surprisingly simple. Especially when you compare it to the already mentioned IMS B108, which had an FPGA and two C101 protocol converters.
Without any C101 you can be assure that there won’t be any downward compatible communication as we are used to with the T4xx/T8xx Transputers (OS-Link), so this will be a hard nut to crack :-/

Let’s have a closer look at the “logic side of things”:

There are only 2 ICs: An AMD MACH 210 CPLD and an AMD 4701, which is an 8-bit bi-directional 512 byte deep FiFo Buffer and parity-generator. Given the fact that there’s a place left for IC2, I assume a 2nd 4701 could go there to make the interface 16bit wide (as all 16 ISA data-lines are connected on the slot-connector).

This leads to my totally uneducated guesses, that:

The DS data-links are directly connected (through the FiFo) to the ISA bus
The control registers of the AM7401 needs to be set – if the default state is not sufficient

Quite a solid foundation to those assumptions is the following schematic I was able to dig out of the depth of the internet describing an IEEE 1355 interface. IEEE 1355 is the standard which was created out of INMOS’ DS-Links.

Everything else…

The function of the colourful DIP-Switch is yet completely unknown. It’s clear that some of these switches will set the base-address for communication with the ISA bus.
The sense behind the two Sub-D connectors at the cards backplate are unknown, too. Maybe some link-outs?

(To be continued…)

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HTRAMs