Browse Prior Art Database

Typewriter Display of Proportionally-Spaced Characters

IP.com Disclosure Number: IPCOM000039743D
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-01

Publishing Venue

IBM

Related People

Authors:
Clark, RE Loiselle, JT Solie, RO VanDyke, MS [+details]

Abstract

Proportionally-spaced characters are displayed on an all-points-addressable (APA) display in exactly the way that they are to be printed on a sheet of paper. The display of the proportionally-spaced characters uses printer control information for proportional-spaced character placement, underscore length, and cursor control. Proportionally-spaced characters are displayed on an APA display, such as a cathode ray tube, by passing a character code, which allows selection of the correct character font data, and a printer carrier position, which is the actual position of the carrier of the typewriter, to a Display Control processor. Using the printer carrier position, the Display Control processor calculates a base character position and an offset from that position for the specific proportionally-spaced character.