This traditional configuration found in a Radio Shack document can use 2N2646. More keys can be added, and the power can be supplied with voltages from 9 to 15 V.
This circuit was found in an American 80s circuit manual. The components used are unusual. The...
The circuit was originally designed to operate with MSX microcomputers in 1988 but can be used to...
This TTL decoder circuit for PC ports was found in a document from 1992. The power supply can be...