DASD CAPACITY IN EXCESS OF 528 MEGABYTES APPARATUS AND METHOD FOR PERSONAL COMPUTERS

摘要

This disclosure relates to translating cylinder-head-sector (CHS) addressing of digital data written to or read from a DASD so as to accommodate DASD storage capacities in excess of the approximately five hundred twenty eight megabyte capacity limit imposed by Interrupt 13 design in an Industry Standard Architecture personal computer system. A CHS (cylinder-head-sector) address in a first frame of reference which meets the restraints of Interrupt 13 design in the ISA BIOS is translated to a CHS address in a second frame of reference which meets the physical characteristics of a DASD which is otherwise outside the restraints of Interrupt 13 design in the ISA BIOS. Determination of a conversion factor for translation of CHS addresses between the first and second frames of reference for cylinder and head numbers, conversion, and translation can occur as a function of the system BIOS in cooperation with the system CPU; as a fucntion of a controller card BIOS in cooperation with a controller microprocessor; or as a function of an IDE BIOS in cooperation with an IDE microprocessor.