Stable High-Speed Digital-to-Analog Conversion for Storage Tube Deflection

A barrier grid tube is a specialized cathode r a y t u b e developed for high-speed electrostatic storage. Instead of a phosphor screen which changes the electron beam into visible light, there is a target area which stores isolated regions of charge under beam action. A binary " 1 " is recorded by charging a small target area ("spot") to equilibrium with the beam when the target surface is modulated by a back plate voltage pulse, while a " 0 " is stored by charging a spot to equilibrium in the absence of the back plate voltage pulse. Information is "read o u t " the next time the beam is turned on a spot (in the absence of a back plate pulse), t h e " 1 " giving a large o u t p u t until t h e spot reaches equilibrium. T h e barrier grid store, which is a random-access, single-bit, binary memory, utilizes the barrier grid t u b e as the storage device. To function properly, t h e store must have a deflection system which converts a binary address to an analog voltage t h a t deflects the barrier grid tube beam to a unique physical storage location. A barrier grid store 1 and a 445