3 ms·

"Lastly, the transputers are quite small (20k gates) and power efficient." I think ARM2 would have been a very competitive choice in that era. ARM1 had 24800

"Lastly, the transputers are quite small (20k gates) and power efficient." I think ARM2 would have been a very competitive choice in that era. ARM1 had 24800 transistors or ~6000 gates [0]. ARM2 had 27k transistors [1], couldn't find a source about how many gates it got, but probably less than 7000. No FPU, though, but up to 16 cycle integer multiplier and multiply-add. In comparison, 16 bit x 16 bit = 32 bit multiply on an MC68000 could take up to 70 cycles. Nevertheless, transputers were pretty cool way back then. I remember drooling after them. As is the project in the linked article. (Side note: As much as I like Motorola 68000 CPU range, it's a pretty sad comparison — it had 68000 transistors and a fraction of performance of an ARM2 CPU.) [0]: https://en.wikichip.org/wiki/acorn/microarchitectures/arm1 https://en.wikichip.org/wiki/acorn/microarchitectures/arm1 [1]: https://en.wikichip.org/wiki/acorn/microarchitectures/arm2 https://en.wikichip.org/wiki/acorn/microarchitectures/arm2

lproven 5y ago
> Motorola 68000 CPU range [...] it had 68000 transistors (!) Is that the origin of the chip's name? The ARM2 was highly competitive, yes. I still own my original ARM2 system from the late 1980s, an Acorn Archimedes A310. It has been odd to see the techie world getting excited over Apple's Arm-ISA CPU performance, some 35 years after much the same thing happened when the ARM2 hit the retail market. I bought my A310 used for £800 in 1989. At the time, my employer's top-end fastest system was an IBM PS/2 Model 70 H21 (I hope I have the model number right): an 80386DX at 25MHz with _external cache_, a radical new feature. It cost about £10,000 (without optional extras such as a keyboard or MS-DOS). My home computer was 2-4x faster, at about 10% of the price. I had a software PC emulator that emulated a ~2.5MHz 8086: slow, but usable for DOS. The underlying OS meant that disk access was super fast. In other words, an ARM2 could emulate an x86 in software at competitive speeds, as an Apple M1 can do now versus modern Intel CPUs. I think the snags with it were that it had 32-bit wide buses, not long after Motorola introduced the 68008 _narrowing_ the chip's buses to 8 bits wide to reduce costs, and a couple of years before Intel introduced the 80386SX in 1988, narrowing the 80386DX's 32-bit buses to 16 bits, again for economical purposes. A full 32-bit wide motherboard was expensive. The ARM2 really needed its original chipset, too, and that too had restrictions, e.g. MEMC imposing a large-for-the-time 4 kB page size.

lproven 5y ago

> Motorola 68000 CPU range [...] it had 68000 transistors (!) Is that the origin of the chip's name? The ARM2 was highly competitive, yes. I still own my original ARM2 system from the late 1980s, an Acorn Archimedes A310. It has been odd to see the techie world getting excited over Apple's Arm-ISA CPU performance, some 35 years after much the same thing happened when the ARM2 hit the retail market. I bought my A310 used for £800 in 1989. At the time, my employer's top-end fastest system was an IBM PS/2 Model 70 H21 (I hope I have the model number right): an 80386DX at 25MHz with _external cache_, a radical new feature. It cost about £10,000 (without optional extras such as a keyboard or MS-DOS). My home computer was 2-4x faster, at about 10% of the price. I had a software PC emulator that emulated a ~2.5MHz 8086: slow, but usable for DOS. The underlying OS meant that disk access was super fast. In other words, an ARM2 could emulate an x86 in software at competitive speeds, as an Apple M1 can do now versus modern Intel CPUs. I think the snags with it were that it had 32-bit wide buses, not long after Motorola introduced the 68008 _narrowing_ the chip's buses to 8 bits wide to reduce costs, and a couple of years before Intel introduced the 80386SX in 1988, narrowing the 80386DX's 32-bit buses to 16 bits, again for economical purposes. A full 32-bit wide motherboard was expensive. The ARM2 really needed its original chipset, too, and that too had restrictions, e.g. MEMC imposing a large-for-the-time 4 kB page size.