technical people who might be able to
help them; he asked me if I was interested. I said, “Well, I’m just a hobbyist.
I’ve been doing this for fun. But if you
think I can help, I’m willing to give it a
go.” That’s how I joined the embryonic
Acorn, before it was Acorn.
Was it based inside sinclair’s building
at the time?
Yes, the first things we did were in
the Science of Cambridge Building in
King’s Parade. Chris Curry was set up
running Science of Cambridge with
Clive. Hermann and Chris did bits of
Acorn work in there. In fact the first
thing I did for Acorn was actually not for
Acorn, it was for Science of Cambridge.
I hand-built the prototype MK14; I got
a circuit diagram and built one using
Verowire, soldering in my front room.
The MK14 was basically a copy of the
National Semiconductor SC/MP development kit. They had taken what was
a masked program ROM from the development kit and copied it into two
fusible link PROMS for the MK14, and
they managed to copy it wrong. So I debugged this thing in my front room. That
was the first piece of work I did for them.
Then Chris and Hermann got a contract to do some development work
on microprocessor controlled fruit
machines, which were very new at that
time. Up to that date fruit machines had
all been controlled by relays and so on;
this was an early attempt to do microprocessor stuff. We used two SC/MPs
in a rack to control the fruit machine.
In fact, the software for that was boot-strapped from the 2650 machine I built
in the Processor Group; it was used as
a dumb terminal into the SC/MP development kit, and we brought this fruit
machine controller up. The main challenge in those days was to make these
things robust. Very early on people had
discovered if you just sparked electronic cigarette lighters next to the fruit machine, they would often pay out.
PHo ToGraPH Cour TeSy oF STeVe FurBer
yes, the program counter jumps off
somewhere and anything can happen!
Yes. So that was when Sophie Wilson came in. She designed an FM receiver front end that would trigger
whenever you flicked one of these cigarette lighters and cause the SC/MPS to
reset; it would definitely not pay out.
[laughs] That was the requirement—if
you interfered with it, it should definitely not pay out. The things were
tested by plugging a mains adapter
into the wall, plugging the fruit machine into one socket, and an arc welding transformer into the other. Somebody welded metal together while you
operated the fruit machine to see if the
thing was robust to sparking.
fantastic! the feeling at that time was
very much of the hobbyist. you just enjoyed doing that kind of thing, and the
whole industry has pretty much come
out of that. Is that fair to say?
Yes, that’s right. We are talking about
the late 1970s before the IBM PC started,
before the Apple II had appeared. There
were some very basic box machines. I
think the Altair had probably appeared
about this time in the States.