Finally got my old 7400 chips organized after years in a shoebox

I did the same sort of cleanup last winter with a shoebox of parts from my community college days in the early 2000s. Mine were mostly CMOS series chips and a handful of op-amps, and about a third of the legs were bent or corroded from sitting loose in the bottom of a toolbox for fifteen years. I lost a quad NAND and a couple of flip-flops to snapped pins before I finally bought a roll of conductive foam. Now everything gets stuck in foam and goes back in the same spot every time.

The binary counter idea is a good one. I rebuilt a simple clock divider circuit last spring just to prove to myself I still remembered how, and it came back faster than I expected. The fiddly part was the breadboard itself, actually. Mine was so old that the spring contacts had gone loose and the chips would pop out if you looked at them wrong. A new cheap breadboard fixed everything.

On labeling, I went a step further and started writing the date on the bags too. Sounds silly, but it's been handy for figuring out which parts came from which project when I'm digging around months later. Also, check any old electrolytic capacitors in that box before you reuse them. The ones from my old projects were all bulged or dried out, even though the chips themselves tested fine.

I took the opposite habit from my college days, mine never ended up loose. Every project got soldered onto perfboard before I called it done, so my 74LS90s and the pair of 74181s I was weirdly proud of are still sitting inside an old binary clock and a half-broken frequency counter on the shelf. Once or twice a year I dig out the clock, clip a 9V battery leads to it, and it just runs like it's 1998 again. Something satisfying about gear that still works after twenty years of dust.

My problem was always forgetting what I owned. Loose chips in bags turned into mystery grab bags within a semester, so I started keeping a spiral notebook with one line per part, how many I had, and what project it went to. Silly low-tech solution but it stuck, and I still do it for the modern stuff too.

The unfinished voltmeter part of your post hit home though. Mine was a digital thermometer with an LM35 that never got past the breadboard stage, and the breadboard itself is still in the closet with the wires intact. Part of me wants to finally finish it, part of me thinks leaving it frozen in time is the whole point.

Second reply nailed it about the breadboards. I pulled mine out of storage a couple years back and one whole column just refused to make contact anymore, cost me an afternoon of blaming my wiring before I figured out the board was the problem. Replaced it with a cheap one and everything I built worked first try. Also agree on the counter project being the right call, mine ended up running off a 555 for the clock and it was oddly satisfying watching it count in binary on the display again.