Browse Prior Art Database

Monitor Identification Technique

IP.com Disclosure Number: IPCOM000039706D
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Janick, JM: AUTHOR [+2]

Abstract

A method of identifying which of several types of CRT displays are attached to a common workstation logic unit without using dedicated identification wires in the interconnecting signal cable is described. The logic unit must sense the display type in order to transmit appropriate display timing and color or monochrome signals. The logic unit usually includes a separate oscillator for each display which limits the use of displays developed and marketed subsequent to release of the logic unit. It is proposed that each oscillator be included within its respective display 1 and that the oscillator be adapted to generate and supply the dot clock signals to the display adapter 2 of the logic unit over the dot clock line 3, as shown in the drawing.

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Monitor Identification Technique

A method of identifying which of several types of CRT displays are attached to a common workstation logic unit without using dedicated identification wires in the interconnecting signal cable is described. The logic unit must sense the display type in order to transmit appropriate display timing and color or monochrome signals. The logic unit usually includes a separate oscillator for each display which limits the use of displays developed and marketed subsequent to release of the logic unit. It is proposed that each oscillator be included within its respective display 1 and that the oscillator be adapted to generate and supply the dot clock signals to the display adapter 2 of the logic unit over the dot clock line 3, as shown in the drawing. The logic unit uses the dot clock signals essentially in the same manner as in the earlier systems. This, however, permits newly introduced displays with their own dot clock signals to be used with the earlier existing logic unit. Identification of each display is achieved by using the dot clock signals of that display to drive a counter 4 in the logic unit. The microprocessor 5, during power-on, gates dot clock pulses from each display into counter 4 for a predetermined time interval. The count in counter 4 at the end of each interval is used to determine which types of displays are connected, and this information is stored for subsequent use by the logic unit during normal system operation....