Browse Prior Art Database

Combined IBM 3101 and Digital VT100 Display Service

IP.com Disclosure Number: IPCOM000037217D
Original Publication Date: 1989-Nov-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Pelt, AB: AUTHOR [+3]

Abstract

Disclosed is a programming concept for combining the functions of both the IBM 3101 and Digital VT100 displays into one display routine.

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This is the abbreviated version, containing approximately 86% of the total text.

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Combined IBM 3101 and Digital VT100 Display Service

Disclosed is a programming concept for combining the functions of both the IBM 3101 and Digital VT100 displays into one display routine.

The display functions of both IBM 3101 and Digital VT100 async terminals were contained in one display service routine by combining functions and using common code in the following areas: 1) Case Selection - Used case selection conditions. Same function between emulators was mated with one function request case condition. Later, code spread/split based on VT100 or 3101 or both. 2) Erase End-of-Line - Affected area/length was calculated. Emulator specifics were handled. 3) Erase End-of-Screen - Affected area/length was calculated. Emulator specifics were handled. 4) Scrolling - One scrolling routine was used for both to scroll forward and backwards and clearing the display. 5) Updating Physical Display - Common computation of start point in display and length of update. 6) Determining How Much of Display Changed - Used minimum/maximum routine to compute start and end point for display update when less than entire display changed. Values of variables used in routine were key. 7) Sending Host Data - Shared code to construct escape sequence and data buffers for transmission to host. 8) Character Updates on Display - Shared code to update a character on display. 9) Tab Function - Shared code to search for next tab stop. 10) Cursor Movement - shared code for cursor movement keys tend...