Browse Prior Art Database

Optimizing Tape Motion Control

IP.com Disclosure Number: IPCOM000075964D
Original Publication Date: 1971-Dec-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Dumstorff, EF: AUTHOR [+2]

Abstract

Magnetic tape drives and similar devices require a variety of timed control signals to assure proper operation. For example, after the drive has been signaled to start tape motion, sufficient time must be allowed to pass before writing or reading to make certain that the tape has come up to proper speed.

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Optimizing Tape Motion Control

Magnetic tape drives and similar devices require a variety of timed control signals to assure proper operation. For example, after the drive has been signaled to start tape motion, sufficient time must be allowed to pass before writing or reading to make certain that the tape has come up to proper speed.

This circuit provides a wide variety of sequential timing signals. Control signals 1-n are generated in the tape controller. Only one signal is active at a time. Each control signal is effective to gate pulses from clock sources A, B and C, through the AND gates feeding OR 5. The output of OR 5 is applied to the increment input of counter 6. Counter 6 has a plurality of output taps 7-10 representing predetermined accumulated values. The signal on each output tap is combined with a control signal 1-n to generate the respective timeout signals and reset counter 6 through OR 11.

Assuming that clock A generates a 1 mHz signal, and tap 7 is connected to counter 6 in a fashion to provide an output signal when an accumulated count of 15,000 pulses is reached in counter 6, timeout 1 signal represents a 15 millisecond delay. Longer or shorter timeout periods can be obtained by using clocks of different frequency, as well as selecting other decodes or taps on counter 6. A pulse generator mechanically coupled to the tape drive could also be used as a source of clock pulses, for example, where it is desired to move the tape a predetermined dist...