Issue No.05 - May (1969 vol.18)
E.O. Gilbert , Applied Dynamics
The exceptional computational speed of hybrid computer systems is closely related to the performance of analog computing elements such as the dc operational amplifier. Development of these computing components has progressed at a rate comparable to that encountered in digital computer technology. One example of this progress is the described computing amplifier which utilizes an interesting mixture of discrete and integrated circuitry.
E.O. Gilbert, "R69-11 A New High Performance Computer d-c Amplifier", IEEE Transactions on Computers, vol.18, no. 5, pp. 477, May 1969, doi:10.1109/T-C.1969.222694