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Selecting Between Keyboard Connectors When the System is Locked

IP.com Disclosure Number: IPCOM000120595D
Original Publication Date: 1991-May-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 80K

Publishing Venue

IBM

Related People

Eng, RC: AUTHOR [+3]

Abstract

This article describes a method and hardware implementation to prevent use of a computer keyboard while permitting the computer system access to it to perform initialization.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Selecting Between Keyboard Connectors When the System is Locked

      This article describes a method and hardware
implementation to prevent use of a computer keyboard while permitting
the computer system access to it to perform initialization.

      In an industrial computer designed for environmental extremes,
ease of maintenance, high performance, and unattended operation, the
system enclosure holds cards in shrouds which plug into the front of
the unit.  Instead if a planar board, there are two system cards, a
processor card and a system resource card, which plug into a passive
backplane.  The processor card contains the microprocessor, cache,
math coprocessor, and system ROM.  The system resource card provides
interfaces for keyboard, video, diskette, and communications.  A
keyswitch located on the system resource card allows the user to
either lock all keyboard inputs or permit all keyboard inputs.

      The system resource card has keyboard connectors on the front
and bottom of the unit.  The front connector provides easy keyboard
access for systems with temporary or hot-pluggable keyboards.  The
bottom connector is designed to give an interface for systems with a
permanent keyboard or those installed within a rack enclosure.

      There are two possible keyboard connections on the system
resource card.  Initialization code within the system ROM must
determine which connector, if either, has a keyboard attached.  If no
keyboard is attached, then the front connector provides the keyboard
interface.  This supports a temporary or hot-pluggable keyboard.

      A keyswit...