Browse Prior Art Database

Selection Circuitry

IP.com Disclosure Number: IPCOM000095086D
Original Publication Date: 1965-Sep-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Snyder, JE: AUTHOR

Abstract

Computers frequently operate with several magnetic tape units. Selection circuitry is provided for selecting a particular tape unit. Control circuitry is provided for operating the selected unit. The drawing shows control circuitry at the top for a computer having a single tape unit. If other tape units are added to the system later, the selection circuitry at the bottom of the drawing is plugged in to the existing control circuitry.

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Selection Circuitry

Computers frequently operate with several magnetic tape units. Selection circuitry is provided for selecting a particular tape unit. Control circuitry is provided for operating the selected unit. The drawing shows control circuitry at the top for a computer having a single tape unit. If other tape units are added to the system later, the selection circuitry at the bottom of the drawing is plugged in to the existing control circuitry.

The circuit comprises trigger circuit T that is connected to be set when the unit is to perform a particular operation such as rewind. To stop the rewind operation T is reset. For a single tape unit, the output of T is connected directly to the tape rewind device A through a circuit having two terminals connected by a jumper.

For operating two rewind devices A and B, the jumper is removed and the selection circuitry enclosed in the dashed line is plugged into the two terminals. The selection circuitry includes selection inputs. These are arranged to be energized when the associated rewind device is to be operated. Gating circuits responsive to the selection inputs connect the T output at one of the jumper terminals to the control lines of the individual tape rewind devices. The control line that corresponds to selection of the original unit A is connected to the other terminal of the jumper where through previously existing conductors it goes to the original single rewind unit. The control line associated with sel...