Browse Prior Art Database

Micro Channel Buffer Card Tester

IP.com Disclosure Number: IPCOM000105069D
Original Publication Date: 1993-Jun-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Martinez, P: AUTHOR [+2]

Abstract

The Micro Channel* Buffer Card Tester is a tool designed by us to test the Micro Channel Buffer Card, IBM Tool Nos. 00G1434-0 and 00G1641-0. It is a self-contained tester with its own power supply. It uses 7485N comparator modules to compare the four-line groups used by the Harris switches of the Buffer Card with a reference oscillator of the tester.

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Micro Channel Buffer Card Tester

      The Micro Channel* Buffer Card Tester is a tool designed by us
to test the Micro Channel Buffer Card, IBM Tool Nos.  00G1434-0 and
00G1641-0.  It is a self-contained tester with its own power supply.
It uses 7485N comparator modules to compare the four-line groups used
by the Harris switches of the Buffer Card with a reference oscillator
of the tester.

      The reference oscillator is a LM555 circuit with components
select- ed so that it provides a switching signal at the rate of
about 1 cps.  This signal is distributed through several 74LS04
inverter modules to the "A" input leg of each comparator.  This same
signal is also distrib- uted to a Micro Channel bus connector on top
of the fixture where the suspect Buffer Card is installed.  When
power is applied, the reference signal is gated through each Harris
switch of the Buffer Card and then brought back into the tester and
routed to the "B" input of the comparators.  If all signals compare
"good", a LED as the load output of each comparator will stay lit.
If the signals don't compare (due to a faulty Harris switch), the LED
will blink at the reference oscillator rate (1 cps).  The blinking
LED will correspond to the defective switch module on the Buffer
Card.  Isolation takes less than a minute.

*  Trademark of IBM Corp.