Configurable disk memory servowriter

Claim 1

A configurable servo pattern writer for writing a selected servo pattern composed of a plurality of servo pattern types which are to be written in a selected order onto a magnetic disc of a magnetic disc drive data storage device, comprising: (a) clock signal producing means for providing a plurality of clock signals which bear a fixed relation to one another and which differ form one another with respect to one of frequency and phase; (b) pattern type control signal generating means for producing control signals representative of a desired servo pattern type; (c) a programmable gate array composed of a plurality of logic gates and programmable interconnection means for interconnecting said logic gates in a logic pattern in response to program signals, said programmable gate array having a plurality of signal inputs connected to receive the plurality of clock signals and the control signals and a single data output for providing an output signal dependent on the clock signals, the control signals and the logic pattern in which said logic gates are interconnected; (d) a servo read-write head having a signal input connected to said data output of said gate array and constructed for writing upon a magnetic disc a servo pattern corresponding in form to the output signal provided at said output of said gate array; and (e) means for storing, and applying to said interconnection means, a logic gate interconnection program which defines an interconnection of said logic gates in a pattern for giving the output signal at said data output of said gate array the form of the selected servo pattern.