Method and apparatus for processing information data

Claim 1

A data processing apparatus of the type having an external data storage medium, said apparatus comprising: a host computer for generating macrocommand instructions for initiating data transfer between said host computer and said storage medium, each macrocommand instruction representing a series of predetermined instructions to be executed as a microprogram routine; microprogram control means responsive to a macrocommand instruction from said host computer for generating a respective set of microprogram instruction steps determined by said macrocommand instruction; memory means for storing data from said host computer for subsequent recording on said storage medium and for storing data reproduced from said storage medium for subsequent supply to said host computer; recording and reproducing means for recording the data supplied from said memory means on said storage medium and for reproducing the data stored on said storage medium for supply to said memory means; and memory control means responsive to a respective set of microprogram instruction steps for controlling the supply of said data to and from said memory means and including control data storage means for storing control data indicating a start address in said memory means and a desired number of data to be transferred, the data transferred to and from said memory means being stored in and retrieved from, respectively, addresses in said memory means starting from said start address and having a number corresponding to said number of data to be transferred.