Date   : Wed, 10 Nov 1999 11:09:10 -0000
From   : "Fraser, Colin J" <Colin.Fraser@...>
Subject: 16 bit BBC ?

Got my Acorn Communicator from Bull today - 25 quid well spent IMO.
Lots of nice bits in there - 4 * 64k Eprom, 32 SRAM etc, nice keyboard.
If I can get it talking to the Beeb I might not strip it but...

The processor is v. interesting.
It is a 65816 - a 16 bit version of the 6502.
It can run in an emulated 6502 mode, but can switch to native mode, which
allows the use of extra instructions, 16 bits registers, and 24 bit address
space.

I was wondering if this chip would work in a BBC B or Master.
It looks to be pin compatible with the 6502, assuming the extra pins for the
extended memory addressing are disconnected, and the data I have says all
the instruction timing is the same.
Power on default is in 6502 emulation mode.

Might be fun to experiment with some 16 bit routines on a BBC.


Colin f