DOS code in CP/M? Revisited...

[Liam Proven]

On 17 July 2016 at 21:07, David Brownlee <abs at absd.org> wrote:
> On 17 July 2016 at 16:09, Liam Proven <lproven at gmail.com> 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:
>>
>> http://chrisacorns.computinghistory.org.uk/Computers/A540.html
>>
>> This was the Unix R260, but shipping with RISC OS instead of RISC iX.
>>
>> The A540 came with a snazzy SCSI HD:
>>
>> http://www.apdl.org.uk/riscworld/volumes/volume9/issue2/blast20/index.htm
>
> 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.


Fascinating -- thanks for that!

OK, so the HD controller chipset was DMA capable, but did Arthur take
advantage of that fact?

I note that the first PDF datasheet I find for that chip is on Peter
Howkin's Martuan site. Pete is a friend of mine and maints RPCemu as
well as the open-source version of CDE, and is a major Acorn expert.

Said datasheet indicates that the HD63463 needs an accompanying
HD63450 DMA controller for DMA operation.

-- 
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