Browse Prior Art Database

Algorithm for Locating Diskette Drives on Ibm PC/PCXT

IP.com Disclosure Number: IPCOM000060242D
Original Publication Date: 1986-Mar-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Pearce, HB: AUTHOR

Abstract

A method is described which provides a program with the ability to determine the location of the floppy diskette drives in a PC/PCXT. Currently, the number of drives on a PC/PCXT is determined by reading switch settings. The switches only indicate the number of drives present, not the location of the drives. With the introduction of external drives it has become essential that operating systems, application programs, and diagnostics know the location of all existing drives. Another constraint is that media may or may not be present in the drives. This method functions with media, without media, or even with bad media. By using this method, the user is freed from having to configure the system. The program space required is less than one hundred bytes, thus it should put no constraints on existing software.

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Algorithm for Locating Diskette Drives on Ibm PC/PCXT

A method is described which provides a program with the ability to determine the location of the floppy diskette drives in a PC/PCXT. Currently, the number of drives on a PC/PCXT is determined by reading switch settings. The switches only indicate the number of drives present, not the location of the drives. With the introduction of external drives it has become essential that operating systems, application programs, and diagnostics know the location of all existing drives. Another constraint is that media may or may not be present in the drives. This method functions with media, without media, or even with bad media. By using this method, the user is freed from having to configure the system. The program space required is less than one hundred bytes, thus it should put no constraints on existing software. Program Flow:

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The location of the drives may now be determined logically from the switch settings. This is summarized in the table below.

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If a condition is not shown in table, then it is an error condition. Either the equipment is malfunctioning or the switches are incorrectly set. ** It is assumed that if only one external drive is present, then it will be configured as Drive C.

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