OK, I've managed to catch up with the thread now. Nice to see so many replies
(I figured it'd generate a few, but I didn't expect this many :-)
A few individual points:
Re. BBC micro: will definitely have one over here at some point. It'd be nice
to find a US-spec one, but I expect they're a little rare even in the US (I've
There's no real need to get a US-spec one. Any beeb other than th very
early ones will have an SMPSU, and there's a clear link to fit to the PSU
board to make it work on 115V mains. And I am sure you cna find soemthing
that will display one of the Beeb's video outputs (darn it, you've got
composited PAL video or serparate TTL-level RGB signals there).
only ever seen one on the UK side). Main worry about
the BBC though is that
it's perhaps overkill for that initial learning step (i.e. focus on
ROM/RAM/CPU and basic I/O) but is a fantastic machine once initial concepts
have been grasped. (C64 perhaps falls into the same category as the BBC - it
might be a bit too daunting initially simply because it can do so much more
than the basic stuff)
But if you think of soemthign simpler, then it's either hard to larn to
use (becuase yyou don't have a high-level language in ROM), or it's full
of kludges (I am thinkin of the ZX80 and Jupiter Ace here) that makes it
very hard for a beginner to understnad because the tricks are _not_ in
the introductory books.
Maybe a single-board computer based round one of those microcontrollers
with Tiny-BASIC (Intel 8052 and successors, for example). Hook up a video
terminal, and you can play about flashing LEDs on the I/O pins, etc. And
the circuit should be easy enough to understnad.
I'm still not sure how to approach the low-level
electronics side of things.
Way back when in the UK, we had some electronics 'kits' at school which had
basic logic gates mounted on a board and allowed kids to jump wires between
them to make circuits (they contained a few LEDs, an LDR, some switches etc.
too). Blue fronts, with the component legends drawn out in white (you couldn't
actually see the ICs themselves). Did something similar exist in US schools?
That sort of thing might be a good practical introduction...
The problem is that many of the better educational kits are now
collector's items in their own right, and hard to find. There is a review
of some of the currently-available ones in the latest Elektor magazine,
BTW, some of thelm look tolerable with a plugblock type breatboard, real
loose components, and so on.
Actually, wahat I'd doo is get a plugblock, a few simple TTL ICs, LEDs,
series resistors, etc, and teach it that way. Yes, you'll get blown
components, but they're cheap enough to replace.
I'd still like to find a 'simple' machine
for him to play on - something on a
par with a 48KB Spectrum; i.e. just ROM/RAM/CPU, keyboard, cassette storage,
and TV output. Extra credit for having a 'common' CPU such as the Z80 or 6502
Tandy CoCo 1 or 2? It's essentially the Motorola application circuit for the
6883 SAM, so it's straightforward. OK, the CPU is a 6809, which is not as
common as the others, but it _is_ a nice, easy, CPU to learn.
And I cna't believe they're rare.
-tony