APPARATUS FOR PERFORMING DIAGNOSTIC TESTING OF CATHODE RAY TUBE AND FLOPPY DISK SUBSYSTEMS

摘要

A data processing system includes a cathode ray tube (CRT) display subsystem and a floppy disk subsystem. The logic of both systems are verified by generating and transferring a fixed format stream of data bits from the CRT display subsystem to the floppy disk subsystem in modified frequency modulation (MFM) mode and checking the information received by the floppy disk subsystem against the original information presented to the CRT display subsystem. The bit rate of the data stream is varied depending on the number of address locations used in the data RAM of the CRT display subsystem to store each data bit.