Issue No.05 - May (1970 vol.19)
G. Grado , Astrodata Inc.
This paper reviews the impact of solid-state technology on the design and implementation of analog computers. Eight figures show the effects of transistors and medium-scale integrated circuits in the various phases of computer development. Basically, the use of integrated circuits is divided into two areas: logic and linear. Logic, or digital, circuits have been used for the control and address selection in the analog computer. Contrary to the author's claim that electromechanical devices used in the 1958 vintage machines were reliable with proper maintenance, transistor control logic was introduced specifically to improve the reliability and speed of the analog computer. (I do not believe that anyone who had to maintain stepping switches would disagree with me.) The introduction of patchable logic combined with the transistor control logic was a big step forward in increasing flexibility for the computer operator. As integrated circuits became practical from the viewpoint of cost per function, the control and patchable logic changed over to integrated circuits with additional features and flexibility.
G. Grado, "R70-5 The Effect of IC's on the Design of Analog Computers", IEEE Transactions on Computers, vol.19, no. 5, pp. 464-465, May 1970, doi:10.1109/T-C.1970.222956