Browse Prior Art Database

Carousel Positioning

IP.com Disclosure Number: IPCOM000088388D
Original Publication Date: 1977-Jun-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 23K

Publishing Venue

IBM

Related People

Anders, FG: AUTHOR [+2]

Abstract

A rotatable carousel stores a plurality of data-containing cartridges of the cylindrical type in a plurality of peripherally located storage cells. Each storage cell has an assigned unique address as shown, from 00 through 15 for storing sixteen data cartridges (not shown). A read/write station is disposed immediately adjacent one axial end of the carousel for extracting cartridges from the cells under control of data processing circuits (not shown).

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Carousel Positioning

A rotatable carousel stores a plurality of data-containing cartridges of the cylindrical type in a plurality of peripherally located storage cells. Each storage cell has an assigned unique address as shown, from 00 through 15 for storing sixteen data cartridges (not shown). A read/write station is disposed immediately adjacent one axial end of the carousel for extracting cartridges from the cells under control of data processing circuits (not shown).

Of interest here is the operation of the position control circuits which respond to a command to rotate the carousel from a present address P to a new address
N. The position control circuits actuate the motor in a manner for minimizing the elapsed time and, therefore, the minimum distance to move. In the illustration, the carousel is an intermittently moved carousel with the carousel being stationary as the read/write station extracts or returns a data cartridge to/from the carousel. In moving across the boundary between 00 and 15, position control circuits must ensure that the calculated distance D is correct. This is achieved by calculating a distance D' in the event there is a possibility that the numerical boundary is crossed. This is achieved by using either a ones- or twos- complement arithmetic correction factor.

The illustrated program for a microprocessor (not shown) in the position control circuits for calculating distance to go first includes the calculation of the actual distance in...