> Nowadays the circuit would hardly rate
> a second glance but then it was an eye opener to me.

I disagree!  I think it would most likely receive lots of admiring glances
from modern electronics designers.  The thing is, no-one would dream of
implementing Pong in hardware these days: it's just crying out for a
software solution.  Similarly, video signal generation is just handed over
to a two buck chip these days.

No, I would say that for sheer ingenuity, electronics designs probably
peaked back in the late '70s (i.e. before the widespread adoption of
microprocessors and microcontrollers, and VLSI chips).  I've seen some
amazing stuff done with boards chock full of CMOS and TTL chips (plus the
inevitable analogue driver board bristling with power transistors and heat
sinks!).  You gotta hand it to those guys, they were just brilliant.

I have a pal who used to work in the games machine industry (Bell Fruit in
the UK).  Monstrously complex non-microprocessor designs continued on for
ages in their industry.  The manufactuers had access to a wide range of
functional modules which they'd developed over the years and were very well
tried and tested.  They had a tremendous amount invested in those designs,
and they had a tremendous amount invested in the expertise and training of
their electronics guys.  Some games machines from the late 70's and even
early 80's were just packed with PCBs, every one plastered with CMOS and
TTL.  You can imagine that it was pretty scary to throw that lot away and
start again with a microprocessor!  It means a complete revamp of your
entire development and manufacturing environment, plus a big churn of staff,
plus another revamp of the support infrastructure........

There was also an interesting interim period when they would use EPROMS -
i.e. a microprocessor support chip - in non-micro applications.  For
example, they would often use them to store those jazzy lighting sequences
for the front panel.  The EPROM was built into the TTL/CMOS circuitry,
rather than sitting on an address and data bus.

Ah, reminiscing is good for the soul!  Or are we old farts just being boring
bastards?

Steve Thackery
Suffolk, England.
Web Site: http://www.btinternet.com/~stevethack/