Browse Prior Art Database

Checking Readback Amplitude Threshold Adjustments

IP.com Disclosure Number: IPCOM000078937D
Original Publication Date: 1973-Apr-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

Angstadt, RA: AUTHOR [+3]

Abstract

Described is an automatic method for testing operation of readback portions in magnetic recording apparatus. A set of thresholds is established by computer control and tested on a track-by-track basis, to successively test each of a plurality of readback signal apparatus for ascertaining proper adjustment.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 2

Checking Readback Amplitude Threshold Adjustments

Described is an automatic method for testing operation of readback portions in magnetic recording apparatus. A set of thresholds is established by computer control and tested on a track-by-track basis, to successively test each of a plurality of readback signal apparatus for ascertaining proper adjustment.

Using the IBM System/360 input/output techniques, the test is initiated by a SET DIAGNOSE command. Chained to the SET DIAGNOSE command is a command that either sets the test to a low or high-amplitude threshold. With a low threshold, all signals recorded on the tape (as will be described) should be read back. On the other hand, after setting a high threshold, no signals should appear. Additionally, other thresholds may be set for more precisely ascertaining the readback characteristics of the magnetic recording apparatus.

In a 1/2'' tape environment, the format on tape used to test each of the readback signals includes a tape mark for demarking beginning of file; and a record is recorded adjacent the tape mark which has no purpose with respect to the test, except for positioning control. In the test area, one track at a time is recorded as described in the IBM Technical Disclosure Bulletin, November, 1971, in an article entitled "Program Generated Recording," by G. H. Edstrom et al, Pages 1821 and 1622. In the preferred form of testing the readback circuits, each track is successively recorded with a predetermined number of bit signals. The connected CP...