Microcontroller? We don't need no microcontroller!

Here’s a shot of a digital clock (I think!) or maybe its a 7-digit counter, I don’t recall anymore, I found it in a box in the basement while looking for something else.
555 with RC & trim pot for clock source, some 7404/7400/7408 across the bottom
2nd row is 6 74163s and a 74160, so 28 bits of synchronous counter
3rd row, a 74H74 and parts likely cannibalized for something else (they are wired up)
4th row is 7447’s driving the digits, which are HP 5082-7730s.

Things that look like burn marks are epoxy, apparently I reused this piece of non-copper clad perfboard.
Back is mix of wirewrap, caps soldered on the sockets after wiring, and point to point soldering for the resisters to the LED leads (be tough to reuse those now!).

Ah, the good old days - parts are dated coded 1978, 1978, so was probably built when I was co-op student after college sophomore year.

Cool, I've got something similar I should take some pics of. Now for the $64K question ... does it still work?

Not without some effort - add a 5V source, find the hand drawn schematic somewhere and see what else is missing. Its in great shape for being 30 years old tho.

That look interesting... Can you re-use the parts ? And are you doing revesed engeneer of this board ?

Sure, the DIP just come out of the sockets. Unsolder the caps from the back of the sockets, clean the pins off, undo the wierwrapping. Have a nice handful of parts to work with. Unfortunately the ICs are mostly 74xxx logic (not LS, not HC, not ACT, but straight 74163) and am pretty sure are power hungry little beasties. I don't need to reverse engineer, I can go root around in some more boxes and find my 30 year old hand drawn schematic. Or just design it again from scratch if I really wanted to.

I have other projects I am looking to tackle first, like being able to get boot loadeds on blank uCs and then building up some boards this weekend.

That's fantastic, takes me back.

I wouldn't bother salvaging the chips, each one will draw more power than a modern laptop :) Mind you they might make good heating elements for a high-altitude ballon project.


Are you guys really going to make me dig out my TTL repeater controller?


If you do, I can go find another old project! Maybe we should have another thread ...

Suggest starting another thread in bar/sport with "dinosaur turd circuits" :grin:

My first self-motivated circuit/electronics project was on an arduino 2009 ;)

Maybe we should have another thread ...

Yep, maybe under Exhibitions or Bar sport. I'm sure there's a lot of old projects people would display.


A good idea. This board is mostly for non-outdated electronics ;)