Date   : Mon, 15 Sep 2008 01:50:16 +0100
From   : jgh@... (Jonathan Graham Harston)
Subject: What CPU is in the second processor?

"David Warrington" wrote:
> Is your question, which second processor family? e.g. 65xx, Z80, ARM etc. or
> are you also interested in WHICH 65xx processor, e.g. 65C02, 6510, 65SC12,
 
Which processor, ie, is it a Z80, 6502, ARM, 80x86, 32016, etc?
 
I think the only solution is to do a specific check for a specific
CPU for a specific purpose.
 
Z80Basic's ROM header checks location &FFF4 in the second processor
to see if a Z80 JP opcode is there, and if so assumes it's a Z80
(see <http://mdfs.net/Software/BBCBasic/Z80Basic/Z80TAIL>). This
has worked adequately for Z80Basic+6502 CoPro and Z80Basic+6502+Z80
CoPros.
 
However, this is failing when the ARM CoPro is plugged in, it's
hanging when it tries to talk to the CoPro to read a byte from
&0000FFF4.
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
05:10:36, 18-Nov-2008 - RISC OS time rolls over to &5000000000