Abstract: A microprocessor controls a programmable oscillator, directing it to produce digital pulses of variable width and frequency. The microprocessor generates inputs for the device under test and compares its outputs after one clock cycle with expected outputs. The clock cycle is adjusted repeatedly until the device's time to complete is known. Response times for the system both with and without the device under test are measured and the difference reported.

Abstract: Programmable pin drivers allow PROM pins to be individually programmed and regulated to specified voltages and currents. Each pin is assigned a voltage multiplexer to select a regulated voltage and a power amplifier to supply current. The source voltage to the power amplifier is determined by the maximum and minimum reference voltages needed by the device under test. This allows a full 70 volt range of pin voltages to be seleced without substitution of pin driver parts, although individual parts have a dynamic range of only about 40 volts, and reduces thermal power dissipation. It also allows very fast microprocessor-driven switching of input voltages to pins, by changing the reference voltages assigned to the individual pins' voltage multiplexers.

Abstract: An adapter converts an instruction-controlled processor such as a microprocessor into a PROM programming apparatus. The adapter is compatible with the type of processor having readout circuitry for applying a multibit signal via an internal address bus to a processor socket into which an addressable memory such as an already programmed PROM is inserted for normal processor operation. During a programming operation, the processor socket does not contain a PROM; instead, the adapter is connected between the processor socket and a PROM being programmed. Control circuitry in the adapter receives the multibit signal so as to control the entering of a plurality of data words into the PROM.