Tony Duell wrote:
Hi! When I
designed the N8VEM 6809 host processor it is loosely based on an
article I read for the BBC computer called "Dragon in the tube". I am not
THe Dragon was, of course, the most common 6809-based computer in the UK.
Yes, there never was an official 6809 copro from Acorn - although there have
been at least two homebrew ones (not including the linking of the Dragon).
with the UK microcomputers but apparently 6809 "coprocessors"
were fairly common peripherals on their Z80 and 6502 designs. I used a
Were they? I've never heard of one.
Acorn never (AFAIK) made a 6809 second processor for the BBC micro. The
original series of second processors (in 'chesse wedge' cases to fit
alongside the BBC micro) were the 65C02, Z80A, 32016 (originally 16032
:-)) and ARM 1. There was also a 32016 board with 4 times as much RAM
that was used in the Acorn Cambridge WOrkstation
No, there was no 'official' 6809 that I know of. My list of commercial ones is
as follows (notional OSes in square brackets):
Acorn 65C102 (Master internal TUBE)
Acorn Z80 [CP/M]
Acorn ARM-1 AEK
Acorn ARM-1 A500 (*not* the standalone machine) [Arthur, ARX, RISC OS]
Acorn 32016 "small board" (256k/1M) [PANOS, poss. Xenix or ARX]
Acorn 32016 "large board" (1M/4M) [PANOS, poss. Xenix or ARX]
Acorn 32016 (Master internal TUBE) [PANOS, poss. Xenix or ARX]
Acorn 80186 (Master internal TUBE) 512K [DOS+/GEM]
Acorn 80186 (Master internal TUBE) 1M [DOS+/GEM]
Acorn 80286 [DOS+/GEM likely]
Torch Z80 "Communicator" [CP/N]
Torch Z80 "Tosca" (with local serial comms) [CP/N]
Torch 68000 "Neptune" [Uniplus, CP/N]
Torch 68000 "Atlas" [Uniplus, CP/N]
Torch 80188 "Graduate" [MSDOS]
Cumana 68008 "Upgrade" [OS-9]
PEDL Z80 [unknown]
Crombie Anderson Associates 68000 "Casper" [FLEX]
And known "homebrews":
Dragon/beeb hybrid 6809
Graham Toal's 6809
Jonathan Harston's PDP-11
* I have confirmation that it really did exist, but nobody seems to recall
exact details. Near as I can tell, it ran a serial link between the BBC micro
and the VAX though (rather than TUBE or 1MHz bus), so it's perhaps a loose
definition of coprocessor...
Is this article available on-line anywhere? Or do you
have a reference to
it? It sounds as though it might be worth reading.
I have it, but I'm only finding scans of the second part on the server right
now (from Electronics and Computing Monthly, September 1985). I think the
first part of the article from the previous month's issue is buried in an
email somewhere - if nobody else has it (& you don't happen to have those
magazines anyway) I can go hunting for it.
The software (FLEX, customised for the BBC/Dragon hybrid) had to be sent away
for, and I never could find a copy - if someone has it, I'd love a copy for
the archive... (not least because hooking one of my Dragons to a beeb would be
a fun project one day :-)