This is a typical circuit of a PROM programmer from the 70s. It appeared in the magazine Radio Electronics in 1979. Note that the programming was done manually byte by byte using switches.
This electronic roulette circuit with 10 numbers was found in a Popular Electronics from the 80s....
This circuit has a very high input impedance and a very low output impedance. We found it on a...
This circuit is from an English documentation from 1969. The circuit can be designed based on...