A Survey of Analog Memory Devices

Widespread and persistent interest in the implementation of multilevel logic, conditional probability computers, learning machines, and brain models has created a need for an inexpensive analog or quasi-digital storage element. A number of possible approaches to this problem, ranging from the slow and reliable electromechanical systems to the many forms of charge and flux integration, are reviewed, and the suitability of each device for various fields of application is briefly discussed.