Method to "Filter" Characters From a Character Set
Original Publication Date: 1985-Sep-01
Included in the Prior Art Database: 2005-Feb-19
A method is described to allow only certain sets of characters to be keyable at one time on the IBM Personal Computer (PC) which involves filtering out ASCII characters not specifically defined for the PC's engraved keyboard. The filtering is done by customizing the ASCII- to-EBCDIC translation tables already required to support a plurality of home keyboards. A standard method for PC operators to enter more than the standard 94 ASCII characters (as engraved on the PC inboard keys) is via the ALT + numeric key pad keys. This alternative mode allows all 255 ASCII characters to be created, and works as follows: 1. Operator depresses ALT key, and holds it down. 2. Operator types up to 3 numeric keypad keys in the range 1 to 255. 3. The Operator releases ALT key. 4.