Browse Prior Art Database

Implied Keyboard Change Character Translating Process

IP.com Disclosure Number: IPCOM000060009D
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 2 page(s) / 14K

Publishing Venue

IBM

Related People

Heath, AW: AUTHOR

Abstract

DisplayWrite 3 is a text processor program that is designed to interchange documents with other non-PC-based machines which use primarily code pages 256 and 259. The PC is based on code page 437. The IBM Personal Computer (PC) code page (437) has subsets of characters from Multilingual Graphic (MLG) code pages 256 and 259 and other characters unique to 437. DisplayWrite supports only 256 and 259. The prior art assumed that the operator could only key a 96character subset of keys from code page 437 that was also on code page 256. This was called the home keyboard. For example, the US keyboard versions gave the operator the choice of keyboard WP 001 as in DisplayWriter default, or keyboard DP 103.

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Implied Keyboard Change Character Translating Process

DisplayWrite 3 is a text processor program that is designed to interchange documents with other non-PC-based machines which use primarily code pages 256 and 259. The PC is based on code page 437. The IBM Personal Computer (PC) code page (437) has subsets of characters from Multilingual Graphic (MLG) code pages 256 and 259 and other characters unique to 437. DisplayWrite supports only 256 and 259. The prior art assumed that the operator could only key a 96character subset of keys from code page 437 that was also on code page 256. This was called the home keyboard. For example, the US keyboard versions gave the operator the choice of keyboard WP 001 as in DisplayWriter default, or keyboard DP 103. The character sets filtered out any ASCII code that did not have a corresponding Multilingual Graphic code point in that home keyboard. Thus, the operator was limited to a maximum translation of 96 graphics characters into MLG EBCDIC. Improved keyboard technology has removed the restriction of only 96 characters engraved on a keyboard and resulted in the international character set (337) as a valid home keyboard selection. Character set 337 consists essentially of the entire code page 256. This now introduces a possible operator confusion factor since DisplayWrite will translate all characters that exist on character set 337, and the operator can generate some of those characters by the PC hardware method of holding the alt key and typing the ASCII decimal equivalent of the character code on the numeric pad. For example, on one keyboard, Capital C cedilla is engraved, but on another keyboard, the operator would hold the alt key while typing "128" on the numeric keypad. The PC operating system and hardware that exists logically below DisplayWrite translates this later key sequence into the same sequence as if an engraved key on another keyboard was pressed. Therefore, to DisplayWrite, no difference is detected, but to the operator, the consistency problem now appears. The sequence of "alt" 128 produced C cedilla whereas another sequence such as of "alt" 224 would produce the "Invalid key"...