Browse Prior Art Database

Automatic Sensing of Diskette Drives for Personal Computers

IP.com Disclosure Number: IPCOM000039801D
Original Publication Date: 1987-Aug-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Osborn, NA: AUTHOR

Abstract

A technique is described whereby an automatic sensing circuit determines if one or more diskette drives are installed in a typical personal computer. The circuit eliminates the prior-art need for setting dip switches or the initiation of disk instructions in a SETUP program. Since a personal computer may have more than one diskette drive installed, in prior art the sensing of the number of diskette drives required removal of covers to set a dip switch and/or to follow a procedure in SETUP programming operations. The concept described herein provides a method of polling all possible drive addresses, so as to automatically initiate a self-configuration of the number of drives installed in a particular personal computer.

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Automatic Sensing of Diskette Drives for Personal Computers

A technique is described whereby an automatic sensing circuit determines if one or more diskette drives are installed in a typical personal computer. The circuit eliminates the prior-art need for setting dip switches or the initiation of disk instructions in a SETUP program. Since a personal computer may have more than one diskette drive installed, in prior art the sensing of the number of diskette drives required removal of covers to set a dip switch and/or to follow a procedure in SETUP programming operations. The concept described herein provides a method of polling all possible drive addresses, so as to automatically initiate a self-configuration of the number of drives installed in a particular personal computer. A DISK CHANGE circuit, typically installed in personal computer drives, such as an IBM AT, is used only when the diskette drive is in the SELECTED mode and is implemented by other signals. It is an output circuit, normally used to indicate the removal of the diskette media. The technique to automatically sense the drive utilizes this circuit, but incorporates a pull-up resistor so that the circuit will be high unless an installed disk drive will pull the circuit low. The DISK CHANGE circuit is defined to be low until the drive is commanded to perform a step function. Consequently, at power-on time, this circuit is low if a diskette drive is installed and high when no drive is present. As a...