Mark Bit Generator
Original Publication Date: 1978-Feb-01
Included in the Prior Art Database: 2005-Feb-20
Some systems in the IBM System/37O family have been designed to have the basic capability of storing a doubleword (eight bytes) of data every machine cycle. A store operation in many systems consists in presenting to the storage medium the data bytes to be stored, the address of the data, the marks which identify the bytes of data to be actually stored, and, finally, a store signal itself. As long as the system is storing one doubleword or less and a doubleword address boundary is not crossed, then the store can be performed in one cycle. However, if the data address were such that the doubleword of data to be stored spanned two doubleword locations, then two store operations will be required, and a considerable amount of effort must be made.