Inmos and the Transputer - Part 1 : Parallel Ventures

The Chip Letter

SubscribeSign in

Inmos and the Transputer - Part 1 : Parallel Ventures<br>A transatlantic startup takes on Intel and tries to change the world

Babbage<br>Aug 27, 2023

16

Share

Inmos Transputer Evaluation Platform : capBy I, NobbiP, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=3956370tion...<br>Today’s post is about an ambitious transatlantic startup that set about competing with industry giants, including Intel, whilst simultaneously single-handedly moving computing to a parallel, multi-processor future.<br>Was it decades ahead of its time or was it doomed to failure, and what can we learn from the story?

When Robin Saxby became CEO of ARM, he set out to make the company follow a strategy that was very different from microprocessor market leader Intel. ARM wouldn’t make chips and would avoid competing directly with the US firm.<br>Saxby’s emphatic decision contrasted with the approach of another British microprocessor designer that had followed a strategy that, in some ways, was almost a copy of Intel’s. A startup in the late 1970s, it both designed microprocessors and built them in its own fabs. It also manufactured memory chips that competed with Intel’s. Even the company’s name looked like an imitation of the US giant’s: Inmos.<br>The story of Inmos is fascinating because many of the underlying themes are still relevant today. What role should government support play in the development of advanced semiconductor design and manufacturing? What are the pros and cons of vertical integration?<br>The story also centres around the idea of going from a few cores to parallel many-core systems. About how to deal with challenges such as how the processors in these systems should communicate with each other and what software should these systems run?<br>Today, of course, we have firms making staggering levels of investment in tens of thousand of GPUs all running in parallel to train enormous machine learning models.<br>I worked at a firm that used Inmos products in the 1990s, chosen because they were seen as the most cost-effective way of getting strong floating-point performance on the desktop. In that sense, these products were a precursor of today’s GPUs.<br>Some aspects of the story of Inmos will contrast strongly with today’s world. Most strikingly, how little it cost to set up a brand new semiconductor manufacturer.<br>With an initial investment of less than $100m, not only did the founders of Inmos set out to build a world-class designer and manufacturer of memories and microprocessors. They also set out to radically change the design of computer systems. They would try to do that with a new microprocessor, called the Transputer, specifically designed as the building block for computer systems with many processors.<br>In this post, we’re going to cover the early history of Inmos and the Transputer. In this week’s supplementary post for paid subscribers, we’ll look in more detail at the Transputer. There are quite a few surprises. I think it's fair to say that the Transputer was a highly innovative design, with features that made it uniquely suited to its role as the building block for parallel systems.<br>If you value The Chip Letter , then please consider becoming a paid subscriber. You’ll get additional weekly content, learn more and help keep this newsletter going!

Subscribe

Let’s start with the origins of Inmos, which can be traced back to a bar in Toronto in the Summer of 1977.<br>The Invitation

“How would you like to set up a semiconductor company?”

Those words came from Richard Petritz, who’d been the director of the TI lab where Jack Kilby had earlier invented the integrated circuit. He’d gone on to found Mostek, then the leader in the market for Dynamic Random Access Memories. So it was an invitation that needed to be taken seriously.<br>It was directed to Iann Barron. Barron had just finished a gruelling 36 hours, with little or no sleep, travelling to a computer conference where he and Petritz had been speaking. The conference itself had been chaotic, with renowned computer scientist Edgar Dijkstra insisting on playing the piano to his audience rather than talking about his speech. So Barron was tired and in no fit state to respond.<br>“And I ignored him. I was so out of it. And he asked me about three times. And I, I just never said anything to him. And then the next day I thought, oh, you know, what was all that about? But he had gone. He wasn’t there any more.”

By chance, Barron ran into Petritz again a few days later at Toronto airport, and then on the flight out of Canada, the two men started to talk more seriously about Petritz’s proposal.<br>Petritiz was convinced that the time was right to start a new semiconductor company:<br>“By 1977 it was as clear as the nose on your face that the very large-scale integration circuit was going to have a revolutionary effect on the semiconductor industry. Also, at the same time, the industry was drifting...