DOS code in CP/M? Revisited...

David Brownlee abs at
Sun Jul 17 14:07:40 CDT 2016

On 17 July 2016 at 16:09, Liam Proven <lproven at> wrote:
> In 1987 or so, the early Archimedes like the A305 and A310 came with
> ST-506 controllers and 20-40MB Conner drives. The expensive
> workstation-class models -- Dick mentions having an A500, but that was
> a series, not a model.

The A500 was the development prototype which pre-dated the A310
(originally with pre-multiply ARM1 CPUs). Only a 100 or so made. I
think they used pretty much the same Hitachi HD63463 as the (optional
podule for the) A300 series which I think was DMA capable.

> There was, later (1990), the A540:
> This was the Unix R260, but shipping with RISC OS instead of RISC iX.
> The A540 came with a snazzy SCSI HD:

The A540/R260 was a completely different class of machine, with an
ARM3 and the ability to take multiple memory (each with memory
controller) cards.

> ... but then it was the thick end of three thousand quid.
> Back in '87, I suspect Dick had an A310 or something, with an ST-506
> drive & Arthur (i.e. RISC OS 1 -- an ARM port of the BBC Micro's MOS
> with a desktop written in BBC BASIC).
> So I suspect no DMA... but I don't know.

Think of it as an A310 with integrated disk controller, in a big metal
box with a lot more soldered wires internally :-p

Acorn kept them in internal service for white a while, including for
development versions of RISC OS 3 with the multitasking filer.

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