Date   : Thu, 01 Dec 2005 21:42:06 GMT
From   : Pete Turnbull <pete@...>
Subject: Re: Order of Acorn Computers?

On Dec 1 2005, 14:04, Jules Richardson wrote:
> Peter Craven wrote:
> > Can someone tell me the order of the Acorn Computers in terms of
'release time'
>
> I think the "Full Acorn Machine List" is basically in chronological
order:
>
>    http://www.nostalgia8.nl/banks/machinelst.htm
>
> ... except that:
>
> 1) I suspect the M4 came before the A680

Not sure about that...

> 2) The Electron should be before the business computer range.

... but you're definitely correct there, the Electron came first, and
the text even gives the dates.

But that page misrepresents the Master Compact, which is a particular
favourite of mine for several reasons: partly because I had a modified
one that didn't rely on the big disk box, and was handy for playing
Elite, and partly because I won an internal competition concerning
them. The Compact is quite a different machine to a Master 128.  It
uses a completely different board, case, power supply, keyboard, and
has different expansion interfaces and different firmware.

It misses out the Master Scientific and Master ET (Econet Terminal),
the other members of the five-strong Master Series.  These *do* share
the same hardware as the M128.

It also describes the A410 and A420 which were listed but not sold
(only the A440, and then the 400/1 series), but omits the A310M,
although that was, admittedly, something of a marketing exercise (an
A310 with bundled PC emulator and software).  Ditto w.r.t. the A3000
and The Learning Curve bundle.

There's some information missing from the Olivetti M19 section.  I
still have some of the brochures, so here goes:

      256K Memory (expandable to 640K)
      DOS filing system, using a 360K 5.25" floppy.  Optional 10MB HDD.
      8088 processor (4.77/8MHz).
      5MHz RAM (200ns access time).
      16K BIOS ROM.
      ~0.25 MIPS.

If you're wondering about an 8MHz CPU with 5MHz RAM, it's because 80x86
family processors use lots of clock cycles for one CPU cycle.

The M19 was not a favourite inside Acorn.  We were even less
enthusiastic about the M21 and M24 which were its slightly bigger
brothers.  Fortunately that phase didn't last long.

The text says the R140 is functionally identical to an A440, but that's
not quite true, as there are some differences in the backplane and
interrupt logic.  The result is that you can't quite turn an A440 into
an R140 by just reloading software.  And the drive interface on all
those machines is ST412, not ST506 (nitpick!)

The A540 and R260 were eventually available with 33MHz processors
instead of just 25MHz.

Lastly, Acorn used to get very upset at people mispelling their OS
name.  It's RISC OS, not RiscOS, Risc OS, etc.  One reason is that it's
a registered trademark, and trademark owners have to be careful about
such things, but another is that MIPS own the similar name RISC/os.  I
find it quite amusing that two completely different companies whose
products ended up in head-to-head competition yet absolutely dominating
the processor market chose such similar names for their OSs.

All in all, though, that's a pretty impressive page from Banksie.

-- 
Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York