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Comment by jakub_h | Hacker News Reader

> and showed the world that you could make a fast ARM.

My memory may be a bit hazy, but wasn't one of the demonstrations of the original ARM a program in interpreted BASIC that did in twenty seconds something for which a compiled C program on a 80386 needed thirty seconds? Or something like that?

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There were two experiments that caught my memory back then.

The first was them trying to understand why the ARM chip they had on a test board was working, despite the fact that the power supply wasn't plugged in. It transpired that there was leakage currents from the keyboard which ended up giving the CPU enough power. (Discussed in a Computerphile YouTube video on the origins of ARM.)

The other was a demo of showing an ARM chip being powered off a thermocouple of the waste heat from a 286 (or maybe 386 ... either way an old Intel CPU)

That's demonstrating you can make a fast BASIC on an ARM. What I'm talking about is making a faster ARM cpu. According to Wikipedia, StrongArm debuted at 233 MHz. I can't remember how fast the contemporary implementations were at the time, but I remember that 233 MHz was a lot faster. (For the record: I'm neither fan of ARM nor x86).

It seems to have been introduced the same year as Pentium 2 which had clock rates of 233-300 MHz. I don't know about the architectural differences at that time, but at least currently Intel processors smoke ARMs with same clock rate. The difference was probably a lot less pronounced at that time as the architectures were simpler.

The Pentium 2 was an out-of-order CPU, StrongARM was in-order.

IIRC, StrongARM was about 5-10x faster than contemporary (non-DEC) ARM chips of the time, which topped out around 30-40MHz.

What made BASIC blisteringly quick on it was that the BASIC interpreter that Acorn had originally written for their ARM-based micros was small enough to fit into the instruction cache on the StrongARM. (According to Wikipedia, StrongARM was 16kb I + 16kb D cache, a Harvard Architecture; whereas the Acorn designed cpus only had a 4kb unified cache at the time.) BASIC programs (which were byte-coded) were enormously faster on the StrongARM.

My also hazy memory recalls that at the launch of the Newton, its CPU (ARM610 I think) was described as more powerful than a 486, at the time the chip to lust after.

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