22 Nov
2007
22 Nov
'07
2:59 p.m.
On Thu, 2007-11-22 at 12:39 +0000, Gordon JC Pearce wrote:
On Thursday 22 November 2007 00:28:24 Tony Duell
wrote:
I remember when I realised that an AND gate with both inputs having
negation bubbles was the same as a NOR gate. That was looking at
circuits for the EDUC-8, so that would be '75 or so and I was 11.
Studying that design basically taught me about logic, and I had such a
soft spot for it that I eventually wrote an emulator for it (I never
actually made my own EDUC-8, I couldn't have afforded to at that age!)
I do think a logic trainer would be a good start for anyone wanting to
know how things work, this type of thing:
http://www.maplin.co.uk/module.aspx?ModuleNo=220990&doy=22m11
In fact looking at that makes me want to go out and buy one for myself
for Christmas. Banbury Maplins, here I come...
--
Lawrence Wilkinson lawrence at ljw.me.uk
The IBM 360/30 page http://www.ljw.me.uk/ibm360
The problem is that there are few good books on
computer operation (and
plenty of very bbad ones). I learnt a lot from the Philips P850 CPU
techncial manual, and more from the PDP8/e and PDP11/45 manuals and
printsets. But trying to understand those is really starting at the deep
end.
I think my "lightbulb moment" was with the SC/MP processor, really. Among a
pile of junk that my Dad had salvaged from stuff getting binned at work was a
manual for a Sinclair MK14. I never saw the board, but I still have the
manual.