Programmable decade resistor
W. Duffy, J. Yin, J. Krakower · Review of Scientific Instruments · 1983
The design and construction of a programmable seven-decade resistor which interfaces with the IEEE 488 bus is described. Off-the-shelf commercial manually set decade units are modified for computer control. TTL logic circuitry is used to drive mercury-wetted reed relays which set the decades. The system controller is a Commodore PET (16K) personal computer.