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Verifying Operation of Equipment Check Detection Circuits

IP.com Disclosure Number: IPCOM000085168D
Original Publication Date: 1976-Mar-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 23K

Publishing Venue

IBM

Related People

Angstadt, RA: AUTHOR

Abstract

Online Test (OLT) diagnostics employ a series of channel commands initiated by channel command words (CCW's) to perform automatic diagnostics on equipment attached to a host computer. In one instance, the controller operates with a 1/2-inch magnetic tape. Equipment check detection circuitry is actuated by the program set forth below.

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Verifying Operation of Equipment Check Detection Circuits

Online Test (OLT) diagnostics employ a series of channel commands initiated by channel command words (CCW's) to perform automatic diagnostics on equipment attached to a host computer. In one instance, the controller operates with a 1/2-inch magnetic tape. Equipment check detection circuitry is actuated by the program set forth below.

First, a tape mark TM is written on 1/2-inch tape. This is followed by writing a short record A and writing a long record B ending up at Position 1. Then, a CCW backspace record is issued, causing the tape to be moved to Position 2 wherein the transducers, not shown, are disposed between blocks A and B. Then, a short record is written ending at dash line C, followed by a CCW forward space record. As a result of the forward space record command, a write current failure is indicated by the controller only when the equipment check circuits are operating properly.

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