Browse Prior Art Database

Keyboard Access Method

IP.com Disclosure Number: IPCOM000048507D
Original Publication Date: 1982-Feb-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Cason, WC: AUTHOR [+2]

Abstract

A keyboard access method is disclosed for facilitating serviceability. The method helps to eliminate software errors due to keyboard hardware errors. The method has two features: (1) Key validation. (2) Error counters.

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Keyboard Access Method

A keyboard access method is disclosed for facilitating serviceability. The method helps to eliminate software errors due to keyboard hardware errors. The method has two features: (1) Key validation.

(2) Error counters.

Key validation is accomplished by the following process: The keyboard hardware generates a 7-bit code to represent each key depression. This code results in 128 possible code points to represent the 84 actual keys on the keyboard. The valid codes generated by the hardware are a "sparse matrix" (e.g., they are not monotonically increasing). These code points are normalized in a "tight set" of code points ranging form 0 to 84. This normalization will indicate if the key is valid. Invalid keys are discarded, without audio feedback, and counted.

The keyboard access method maintains counts of the number of discarded keys and also the number of hardware overruns reported. The contents of these counters are available for facilitating serviceability of the keyboard hardware.

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