This circuit was obtained from Motorola documentation from 1969. The setting applies to other operating systems, including lower supply voltages. The zener determines the output signal.
This circuit was found in an 80's Electronic Design. It amplifies TTL fast signals for a coaxial...
This circuit maintains on a flashing LED at a frequency determined by the capacitor. The...
Found in 1965 Radio Shack documentation, this circuit has a crystal phone output in the 14.8 kHz...