Browse Prior Art Database

Disk Drive Head Load Testing

IP.com Disclosure Number: IPCOM000043732D
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Jackson, HC: AUTHOR

Abstract

Diskette read/write heads are loaded against a rotating flexible diskette when a control logic circuit activates an output line. The logic circuit operates to load the heads repeatedly at a previously selected circumferential position, or to distribute the load positions evenly around the diskette circumference depending on the mode selected. This increases the capability of test equipment which is used to test the wear characteristics of flexible diskette media and diskette drive heads. The figure is a logic circuit composed of multi-stage switch 4, binary counters 1, 2 and 3, AND gates 5 and 6, and OR gate 7. The input signal 8 (Fixed) is activated when a fixed point load is desired, and will serve to enable switch 4, counter 3, AND gate 5, and OR gate 7.

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 57% of the total text.

Page 1 of 2

Disk Drive Head Load Testing

Diskette read/write heads are loaded against a rotating flexible diskette when a control logic circuit activates an output line. The logic circuit operates to load the heads repeatedly at a previously selected circumferential position, or to distribute the load positions evenly around the diskette circumference depending on the mode selected. This increases the capability of test equipment which is used to test the wear characteristics of flexible diskette media and diskette drive heads. The figure is a logic circuit composed of multi-stage switch 4, binary counters 1, 2 and 3, AND gates 5 and 6, and OR gate 7. The input signal 8 (Fixed) is activated when a fixed point load is desired, and will serve to enable switch 4, counter 3, AND gate 5, and OR gate 7. If distributed point loads are desired, input signal 9 (Distributed) is activated which enables counter 2, AND gate 6, and OR gate 7. Index input signal 10 is derived from the diskette drive hole sensor, and sends one pulse for every revolution of the flexible diskette. The G input to counters 2 and 3 serves to enable the count function and the zero decode output. Switch 4 and counters 1, 2 and 3 are all seven-bit devices. In operation for fixed point loads, Fixed input line 8 is activated which, in turn, enables counter 3 and AND gate 5. Switch 4 generates a binary number which is loaded into counter 3 when the diskette index hole is sensed on Index input 10. This number is then d...