On Mon, 29 Mar 1999, Tony Duell wrote:
> > What you have then is equivalent to an upgraded Model III, since the
> > Model 4 upgrade was essentially a mobo replacement, all other pieces
> > were the same between the two machines. (Well, floppy vendors
>
> Not quite. The keyboard is different (the model 4 one has extra keys on
> it). Although you can use the wrong keyboard with either machine - the
> extra keys are in unused positions on the 8*8 matrix on the Model 3 and the
> keyboard cable pinout is the same.
You're right, I forgot the Mod III didn't have those (years since
I've actually looked at a III in fact).
> The Model 4 _disk machines_ had a sound board as standard. No idea why
> this was a separate board - all it consisted of was a 7474 D-type (half
> used) + a transistor driver + a minispeaker. As there was an unused half
> of a 7474 on the CPU board right next to the sound connector. It would
> probably have been cheaper to put the few extra components on the CPU
> board. Go figure.
Don't recall ever noticing the sound board. I wasn't all that
hardware hacking oriented in those years.
> > changed back and forth a couple of times). Though some Mod 4s with
> > green tubes got through the system, I'm told (I never saw one).
>
> Do you mean that? I thought all Model 4's had green CRTs. Mine certainly
> does (early S/N non-gate array board)
Total mind-fart on that one. That's what I get for composing
messages at the end of a sleepless weekend. It's the white
screen desktop 4s that were rare, the 4p started out with white
then went green. I did know one guy who dropped his 4p and broke
the tube, went with a third-party amber replacement.
> Model 3's have white CRTs as standard, although there were aftermarket
> replacements with green or amber screens.
Advertised in every epidode of 80-Micro.
--
Ward Griffiths
"the timid die just like the daring; and if you don't take the plunge then
you'll just take the fall" Michael Longcor
Received on Mon Mar 29 1999 - 16:12:51 BST