Diskette drive type determination mechanism

Claim 2

In a computer system having a device attachment port to which any one of a plurality of different types of disk drives may be attached at different times, a method for adapting the system to recognize the type of drive currently attached to said port, automatically and en a dynamic basis, characterized in that it comprises: a first issuing step of issuing a head positioning command to said port for causing the head on the currently installed drive device to be moved in a first direction to a predetermined track address which is not within the range of one cf said drive types, whereby the head is positioned at different tracks in drives of different types; and determining the track address to which said head is moved by said moving to said predetermined track address, whereby said determined address is related to the type cf device attached to said port.

Claim 3

A method according to Claim 1, characterized in that said determining step comprises the steps of: a second issuing step of issuing a further series of head positioning commands to said port for causing said head to move in fixed increments in a direction opposite said first direction to a reference track pcsition; providing a status indication from the drive to said system when the head is returned to said reference position by said fixed increments; counting the number of fixed increments issued by said system prior to said status indication; and associating the count of said fixed increments to the type of drive currently installed at said port.

Claim 4

A method according to claim 1 or 2, characterized in that said first issuing step first issues a head positioning command to said port to cause said head to be moved to said reference track position.

Claim 5

A method according to claim 2, characterized in that said counting step further counts up to a predetermined number, said predetermined number exceeding the counts caused by any type of drive and said associating step associates said predetermined number of counts with the absence of a drive in said port.

Claim 6

A disk controller in a computer system for a disk drive attached to a port of said controller for determining the type of said disk drive, characterized in that it comprises, means for transferring a first signal to said port, said first signal causing a head in a drive attached to said port to move in a first direction to a high track position, said high track position being inaccessible in at least one type of disk drive, said means further transferring a set of second signals to said port, each said second signal causing said head to move in a direction opposite to said first direction toward a reference track position in predetermined increments; means for receiving a reference track signal from said drive, said reference track signal indicating the positioning of said head in said drive at the reference track position; means for counting the number of second signals transferred to said port by said transferring means before said receiving means receives said reference track signal; and means for associating said number with the type of said drive attached to said port.

Claim 7

A disk controller in a computer system for a disk drive attached to a port of said controller for determining the type of said disk drive, characterized in that it comprises, means for transferring a first signal to said port, said first signal causing a head in a drive attached to said port to move in a first direction to a high track position, said high track position being inaccessible in at least one type of disk drive, said means further transferring a set of second signals to said port, each said second signal causing said head to move in a direction opposite to said first direction toward a reference track position in predetermined increments; means for receiving a reference track signal from said drive, said reference track signal indicating the positioning of said head in said drive at the reference track position; means for counting the number of second signals transferred to said port by said transferring means before said receiving means receives said reference track signal; and means for associating said number with the type of said drive attached to said port.

Claim 8

A disk controller according to Claim 5 characterized ir that said transferring means transfers no more than a maximum number of second signals to said pcrt, said maximum number being greater than the number of predetermined increments necessary to move said head to said reference track position from said high track position in a drive of any possibly attached type; and said associating means associates the counting of said maximum number of counts with the absence of a drive on said port.