Browse Prior Art Database

Computer Control of Tape Drives

IP.com Disclosure Number: IPCOM000062107D
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Bancroft, CE: AUTHOR [+4]

Abstract

A technique is described whereby the control circuitry, available within magnetic tape drive units, is modified and connected to computer circuitry so as to enable tape drives to be controlled, through programming, by microprocessors or computers. By providing programming capability, operator intervention is eliminated since the computer is able to control the operational functions of the tape drives. The concept also enables the computer to operate several tape drives simultaneously. The most important requirement in determining if a particular commercially available tape drive can be modified is to determine if an internally generated frequency controls the motor speed. For the computer to control the speed of the tape, a circuit in the computer, such as a counter/timer card, will generate a programmable output frequency.

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Computer Control of Tape Drives

A technique is described whereby the control circuitry, available within magnetic tape drive units, is modified and connected to computer circuitry so as to enable tape drives to be controlled, through programming, by microprocessors or computers. By providing programming capability, operator intervention is eliminated since the computer is able to control the operational functions of the tape drives. The concept also enables the computer to operate several tape drives simultaneously. The most important requirement in determining if a particular commercially available tape drive can be modified is to determine if an internally generated frequency controls the motor speed. For the computer to control the speed of the tape, a circuit in the computer, such as a counter/timer card, will generate a programmable output frequency. The computer-generated frequency replaces the frequency normally used by the tape unit to determine the speed of tape travel. This allows the tape speed to become continuously variable. The only limit on the number of speeds that the tape unit can run is dependent on the number of different frequencies that the microprocessor can produce. The drive signals, which are normally accessible for remote control units, are connected to the digital input/digital output (DI/DO) points of the computer. The computer is then programmed by setting a functional bit so as to control the movement forward, reverse or stopping of...