Found another Relic

richardc64

I mounted a piece of non-clad fiberglass on a wood frame and drew logic symbols on it with felt marker. You see here JK flip-flops, inverters and gates, the last looking much like 2-input inverters because that's how they were illustrated in Don Lancaster's RTL Cookbook, making no distinction as to whether they were positive logic NANDs or negative logic NORs. The worst part was drilling all the holes for IC sockets -- without benefit of a drill press! You can see through the board the residue left on the underside from adhesive copper d.i.p. patterns.

All the IC pins (except +V and Gnd,) were brought out to 4-40 screws, thread end up. Experimental patching was done using alligator clipleads. If I were to repeat this method on a Lunetta I'd probably use longish 2-56s.

Once my RTL synth was developed, and solderless breadboards were starting to become available, (replacing the old breadboarding methods of terminal strips, Fahnestock clips and other spring mechanisims,) I felt that this monstrosity was no longer necessary and disassembled it. Eventually I used chunks of the fiberglass board for one purpose or another; small circuits, using more of those adhesive copper patterns, or for small panels.

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droffset · Posted: Tue Jan 26, 2010 2:06 pm Post subject:

Pretty cool, out of curiosity, how did you connect the wires to the screws? I end up with a messy blob of solder when I try such things, did you use nuts?

richardc64 · Posted: Tue Jan 26, 2010 3:11 pm Post subject:

I just used solid wire, wrapped a stripped end once around close to the screw-head and tightened down the nut on the other side of the panel. You could also use tinned stranded wire.

Solder generally does not "stick" to screws.

electri-fire · Posted: Fri Jan 29, 2010 5:48 pm Post subject:

RF · Posted: Fri Jan 29, 2010 7:14 pm Post subject:

I've got an Elektor Formant synth that was built back in the '70's - and most of the flying wires and harness were built using solid wire. The first huge job I had to take care of when I got it was to repair a LOT of connections where the solid wire was soldered to the PC board. Solid doesn't flex well, to say the least - especially at the stripped ends.
If you use solid - dress and wire tie very carefully so it will not move.

bruce