I can't believe IT STILL WORKS!!!

richardc64 · Posted: Thu Oct 19, 2006 2:48 pm Post subject: I can't believe IT STILL WORKS!!!

This is what started me off. I didn't forget it, I just didn't know where it was. Re-discovered in a box this morning while looking for something else. A very early sequencer published in Popular Electronics, more than 30 years ago. Used RTL ICs: a hex inverter and 2 dual jk flipflops as a 4-bit ripple counter. Sixteen steps seemed too short to me so I extended it to 64 steps by adding another dual flipflop. I also added a dual NOR gate (that's right, only 2 gates to a package) and wired their outputs thru pots to the 2-transistor "vco", like 4 of the inverters. The remaining 2 inverters formed the clock. Instead of hard-wiring flipflip outputs to the inverters and gate, I brought all the Qs and /Qs out to 4-40 screws and and selected different combinations of bits with alligator clipleads. I'll try to find the schematic.

Radio Schlock didn't have .1" hole perfboard at the time so I had to drill new holes in the more common -- at the time -- perf with holes on .156" centers.

So today I put in 2 'D' cells and, damn! It started beepin' and boopin'! I suggest you keep the volume low if you play the wav sample. (The stuff to drive parents and neighbors nuts.)

primitive2.jpg

Description:

Filesize:

94.37 KB

Viewed:

123 Time(s)

This image has been reduced to fit the page. Click on it to enlarge.

pe_sequence.wav

Description:

Download

Filename:

pe_sequence.wav