The transistor regenerative amplifier as a computer element

A method of designing transistor 2-state circuits which accepts transistors having a relatively large spread in characteristics has already been described. Although subsequent improvement in the uniformity of transistors has removed the primary object of the system, it has been retained in the circuits described in the paper because of the many other advantages it confers where accuracy and speed of operation are important. The transistor is considered as a regenerative amplifier, and the first part of the paper describes various methods of connection and endeavours to evaluate the merits of each circuit. The second part illustrates the application of some of the basic circuits to more complex circuits of the type used in digital computers. These circuits operate at a basic frequency of 125 kc/s and use rectangular pulses to allow adequate time for comparing two or more waveforms and performing operations on them. It is concluded that, owing to its adequate stage gain, low output impedance and standard output pulse, the transistor regenerative amplifier constitutes an economical and versatile computer element.