Browse Prior Art Database

Testing Method for Personal Computer Devices

IP.com Disclosure Number: IPCOM000113508D
Original Publication Date: 1994-Aug-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 100K

Publishing Venue

IBM

Related People

Deloye, MJ: AUTHOR [+3]

Abstract

Described is a hardware implementation that allows computer circuitry to pinpoint and isolate errors in Personal Computer (PC) devices, such as keyboard, mouse and controller circuitry. The method presented provides independent isolation of a system unit function through the modification of existing logic circuitry.

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

Testing Method for Personal Computer Devices

      Described is a hardware implementation that allows computer
circuitry to pinpoint and isolate errors in Personal Computer (PC)
devices, such as keyboard, mouse and controller circuitry.  The
method presented provides independent isolation of a system unit
function through the modification of existing logic circuitry.

      In prior art, problem isolation of keyboard port and/or mouse
port circuitry on PC detected failures was possible only when the
specific device, keyboard or mouse, was attached.  A test failure
indicated that either the port and/or the attached device did not
respond properly and isolation of a single entity was not possible.
For example, if the failing sub-system involved the keyboard port, no
diagnostic could be executed since the diagnostic required user input
from the keyboard.  In addition, if a test pass indication was
indicated, only the ports with the attached devices were considered
operational.  A port with no device attached was not tested.

      The concept described herein provides a method that permits
testing of the system keyboard and mouse port independently of an
attached device.  It also provides the ability to isolate the system
unit, or device, as a failing unit.  The Figure shows the circuit
configuration modification to the existing logic that supports the
keyboard port and mouse port.  The circuit modification consists of a
keyboard controller, input buffer and output buffer.  The keyboard
controller drives and receives data and clock signals to and from the
keyboard and mouse ports.  The controller permits an individual line
to be driven logically HIGH or LOW while data is being received.  The
input buffer receives data, or clock, signals from the keyboard, or
mouse, port with the appropriate filtering and passes that signal to
the keyboard controller.  The output buffer drives data, or clock,
signals to the keyboard port, or mouse port, with the required
voltage, current and standby levels.

      During normal output operations, data is sent to the keyboard,
or mouse, by presenting a bit of data on the output buffer for the
data line, and a transition on the output buffer for the clock line.
The sequence is repeated until all the data is transferred to the
appropriate device.  When data is received from the keyboard, or
mouse, a bit of data is presented to the input buffer for the data
line from the device as well as a clock transition on the input
buffer for the clock line.  The sequence is repeated until all data
is transferred.  The keyboard/Mouse testing method provides the added
ability for the keyboard co...