Honeywell Information Systems Inc.

James C Siwik

Thomas O Holtey

Thomas L Murray, Jr

Gary J Goss

A Loadable Character Generator whose operation can be changed to suit various needs, such as foreign language requirements, without hardware change and with minimum hardware. The character generator translates the character code of a character to be displayed to the dot pattern for that particular character, utilizing a minimum of hardware. The loadable character generator of the invention replaces the ROM/PROM by a RAM utilizing 2K and 8 RAM memories, a 4K by 8 memory, 4 MUX chips, and a Motorola 6845 CRT Controller with various registers and is loaded through the attribute buffer.

Variable loadable character generator

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.

Diskette subsystem fault isolation via video subsystem loopback

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.

Growing community of inventors

Nashua, NH, United States of America

James C Siwik