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This is great, though I do sometimes think too much attention is paid to ARM1. This was, fundamentally, a technology demonstrator. The CPU that shipped (in th

by ajross 4y ago

This is great, though I do sometimes think too much attention is paid to ARM1. This was, fundamentally, a technology demonstrator. The CPU that shipped (in the Archimedes) was the ARM2, and it did so a year and a half later and more or less simultaneously with the more famous Sun-4 and SGI Iris 4D boxes. The ARM1 is really a super-clever circuit and worthy of study. But... so were Berkeley RISC (which begat SPARC) and Stanford MIPS (you can guess), which beat ARM1 to the punch by a year and also produced working (in a lab) silicon. And those two were just evolutions of ideas from the IBM 801. And of course the whole paradigm was Really Invented by Seymour Cray. Sometimes I think the story of ARM gets a bit spun. Really it was the Acorn products that were notable, not their CPU design so much.

dboreham 4y ago
To the victor goes the right to write history.
talideon 4y ago
The ARM2 wasn't tremendously different from the ARM1. And the ARM was the major differenciator for their products, unfortunately. It was the beating heart of the Archimedes and RISC PC and the one differenciator they had. Because the MEMC and VIDC weren't, and RISC OS, however nice it might've been, was hobbled by a bunch of early design issues that kept it from making the transition to preemptive multitasking. Never mind the pain of the ARM26 to ARM32 transition. I mean, I could go on. ARM gets credit for being the first properly successful RISC processor, way beyond what MIPS and POWER achieved. It proved that RISC worked by delivering powerful machines that consumed a fraction of the power. They didn't need to be first to do that, they just needed to do it better. The first person to do something is rarely the one to get credit because they probably didn't get the design right. Acorn didn't get it quite right, but they got it right enough to make major waves. And as much as he deserves respect, Seymour Cray wasn't the progenitor of RISC. If anything, his designs ran contrary to them as he was so fixated on building machines with essentially discrete logic.

by ajross 4y ago

dboreham 4y ago

To the victor goes the right to write history.

talideon 4y ago

The ARM2 wasn't tremendously different from the ARM1. And the ARM was the major differenciator for their products, unfortunately. It was the beating heart of the Archimedes and RISC PC and the one differenciator they had. Because the MEMC and VIDC weren't, and RISC OS, however nice it might've been, was hobbled by a bunch of early design issues that kept it from making the transition to preemptive multitasking. Never mind the pain of the ARM26 to ARM32 transition. I mean, I could go on. ARM gets credit for being the first properly successful RISC processor, way beyond what MIPS and POWER achieved. It proved that RISC worked by delivering powerful machines that consumed a fraction of the power. They didn't need to be first to do that, they just needed to do it better. The first person to do something is rarely the one to get credit because they probably didn't get the design right. Acorn didn't get it quite right, but they got it right enough to make major waves. And as much as he deserves respect, Seymour Cray wasn't the progenitor of RISC. If anything, his designs ran contrary to them as he was so fixated on building machines with essentially discrete logic.