AN/FSQ-7: the computer that shaped the Cold War

6 Central processor

The AN/FSQ-7 central processor consists of a number of interconnected elements as shown in figure 6.1. Basically, it is a classic VON NEUMANN-architecture with a central memory subsystem holding instructions as well as data. Depending on perspective, the AN/FSQ-7 can be seen with some justification as a 16 bit computer or a 32 bit computer: The memory word-length is 32 bits plus a single parity bit for error checking purposes, while the basic operations of the computer itself work on 16 bit values in one’s complement. It has been designed this way because the air defense application required a high amount of coordinate transformations. Accordingly, it was decided to implement an arithmetic unit³³⁷ capable of working on two ...