Binarily related variable rate recorder

Claim 1

For use with a computer disc having a format which is such that the data stored, or to be stored thereby, is arranged in generally pie-shaped sectors, said sectors being divided into at least two radially disposed recording zones for recording non-interleaved data in either said zone, each said zone having a respective number of tracks, the first zone being radially outward of the second zone, and the tracks of the first zone being adapted to record respective full blocks of data, said full blocks being respectively comprised of the same given number of data bytes, and the tracks of said second zone being respectively adapted to record half-blocks of data, said half-blocks being respectively comprised of half the number of data bytes which comprise said full blocks, apparatus comprising a. means for receiving data and disc storage address information from a host computer, b. microprocessor means c. a random access memory for use in controlling the flow of data from said host computer to said computer disc, d. magnetic head means, and e. means for controlling the positioning of said magnetic head means relative to said disc, said microprocessor means being connected to said means for receiving and said means for controlling head positioning for positioning said magnetic head means in accordance with said address information and, depending on whether recording is to be effected in a first or second zone of said disc, for causing data to be withdrawn from said random access memory in full or successive half blocks thereof, said apparatus further comprising means for providing first and second clocking signals corresponding respectively to the recording of full and half-blocks of data, said first clocking signal being different in frequency from said second clocking signal, said means for receiving data and disc storage address information receiving data bytes comprised of parallel arrangements of bits, and said apparatus further comprising means for receiving and converting the output of said random access memory to a serial bit format, said clocks being applied to said means for receiving and converting for operating that means selectively at the frequency of said first and second clocking signals.