ard at p850ug1.demon.co.uk
Sun Dec 14 13:13:15 CST 2008
> After doing some looking I thought I'd go with 68020 if I were to do
> 32-bit, or 68000 for 16-bit. I may take Tony's excellent advice and
IIRC, the 68020 has the feature that you can set the bus width by the
states of a couple of pins. This was normally done to allow efficient
access to 8-bit I/O devices (you can change the states of these pins
depending on the current address ,of course), but there's no reason why
you shouldn't hold the pins in the states for an 8-bit data bus and just
have 8 it memory. Of course it's slower (4 memory cycles for each 32 it
access), but it will work.
> try something even simpler first, if I can get my hands on the Art of
> Electronics books... they're on Amazon, I'll probably just have to
> buckle down and shell out the money.
'The Art of ELectronics' is IMHO a book every electronics engineer should
own. There's a lot of good stuff in it. Sure there are the odd things I
disagree with, there are things I'd do differently, but by the time
you've read it, you'll know enough to be able to work out how you'd want
to do things.
My criticism of the Student Manual is that as it was written for a
university course, it assumes you have access to some nice test gear
(like a 'scope, bench PSU, etc). This means the esperiments possibly
can't be done by the average hobyist just starting out. But again there's
a loot of good stuff in it, and I don't think you need too much exotic
stuff for the 68008 circuits.
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