Digital Differential Analyzers with Arbitrary Stored Interconnections

A classification scheme for DDA structures is presented. Various structures are examined with respect to speed of operation and the case of providing stored interconnections. A class of DDAs with a staggered parallel structure is presented and discussed. The use of this DDA structure together with ultrasonic delay lines allows arbitrary, stored interconnections and DDA operation at approximately analog computer speed and accuracy. Various trades between equipment cost, speed of operation, and the number of integrator units are considered for DDAs in this class.