A computer memory made from a continuous sheet of superconductive material is under development at the Princeton, N.J., research center of Radio Corporation of America. In the device, persistent currents store digital data and coincident current is used for selection.
The advantage of using persistent supercurrents for storage, as outlined by RCA researchers, is that they provide steady-state indication of the stored state without requiring steady-state power dissipation to maintain the state.
The memory planes in the RCA storage unit are made by evaporation in high vacuum (10−6 mm Hg) through metal masks. The masks are made by a photo-resist and etching process. Selection logic for the memory will be provided by thin-film cryotrons, RCA reports. (Electronic Design, July 8, 1960, p. 32)
RCA, at its Princeton lab, was one of the leading developers of cryogenic memories. Despite the need for ultra-low temperatures, this work continued throughout the '60s.