Browse Prior Art Database

Method for Controlling Shift Key Information to Applications

IP.com Disclosure Number: IPCOM000062448D
Original Publication Date: 1986-Nov-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Beauregard, GM: AUTHOR [+2]

Abstract

The Terminal Mode Processor (TMP) interprets keystrokes received from the keyboard and returns them to the host application. The TMP has two modes of operation. First is the non-translated mode in which the host receives raw keystroke data (i.e., scan codes and key positions). The alternative mode is full translation. In translated mode the TMP converts a particular keystroke from key position to one or more ASCII codes. For example, if the user presses the key marked 'A', the host will receive an interrupt containing the ASCII code for a lower case a, not the scan code and key position for that key. This is sufficient in all cases but one. If a host application wishes to know when a shift key is pressed (shift keys are the keys marked 'shift', 'alt', 'control', etc.), then it must use the less efficient non-translated mode.

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Method for Controlling Shift Key Information to Applications

The Terminal Mode Processor (TMP) interprets keystrokes received from the keyboard and returns them to the host application. The TMP has two modes of operation. First is the non-translated mode in which the host receives raw keystroke data (i.e., scan codes and key positions). The alternative mode is full translation. In translated mode the TMP converts a particular keystroke from key position to one or more ASCII codes. For example, if the user presses the key marked 'A', the host will receive an interrupt containing the ASCII code for a lower case a, not the scan code and key position for that key. This is sufficient in all cases but one. If a host application wishes to know when a shift key is pressed (shift keys are the keys marked 'shift', 'alt', 'control', etc.), then it must use the less efficient non-translated mode. For example, if the user presses the shift key and the key marked 'A' at the same time, the host will get an interrupt containing the ASCII code for a capital A. The host will never know that the shift key was pressed. Certain applications use the shift keys to change feedback, such as displaying programmed function key assignments. However, they are designed to use translated characters and controls for performance and simplicity of code. To support this use of shift keys, the TMP has a unique special mode and a private escape sequence. The host may, via Supervisor Call (SVC), plac...