High Quality Content by WIKIPEDIA articles! 32-bit Disk Access refers to a special disk access and caching mode available in older, MS-DOS-based Microsoft Windows operating systems. It was a set of protected mode device drivers that worked together to enhance the system's BIOS. It filtered interrupt 13h BIOS calls to the disk controller and directed them in the most efficient way for the system either through the 32-bit interface with the hard disk controller or through the system BIOS. Using 32-bit Disk Access allowed for more pageable memory in Windows to page MS-DOS based applications to disk to free enough RAM for applications when they needed to use it. Sometimes enabling this mode would break older applications of the day.