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Multi-Font Cathode Ray Tube Display Adapter Circuit for a Personal Computer

IP.com Disclosure Number: IPCOM000040704D
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02

Publishing Venue

IBM

Related People

Authors:
Oh, S Stilz, MD Waldrop, DS [+details]

Abstract

A cathode ray tube (CRT) of a personal computer (PC) can display different sizes and styles of characters by using a display adapter circuit in conjunction with a CRT font cartridge having the shape and size of each character. This enables the CRT to display the same number of characters in a line that will appear on a sheet of paper when printed and at a speed at which a typist is activating the keyboard of the PC. A display adapter circuit 1 (Fig. 1), which enables a CRT of a PC to display different sizes and styles of characters, is used in conjunction with a CRT font cartridge 2, which includes a character size ROM 3 and a character generator ROM 4. The display adapter circuit 1 has an MC 6845 programmable controller 5, which has inputs of address, chip select, and timing signals.