Issue No.07 - July (1969 vol.18)
V.L. Larrowe , Institute of Science and Technology University of Michigan
This paper describes a special analog correlator which is used for optical character recognition (OCR). The correlator is built around a special" card capacity read only storage (CCROS)" memory. Each bit in this CCROS memory is represented by a 1-pF capacitor, which may be removed from the circuit by appropriately punching a special Hollerith card on which is printed one plate of the capacitor. The other plate of the capacitor is printed on a printed circuit board pressed against the reverse side of the card, and the portion of the card between the two plates forms the capacitor's dielectric.
V.L. Larrowe, "R69-20 An Analog Card Capacity Correlator as Applied to OCR", IEEE Transactions on Computers, vol.18, no. 7, pp. 669-670, July 1969, doi:10.1109/T-C.1969.222743