Browse Prior Art Database

Fast Page-Mapping System for Personal Computer-Type Small Systems

IP.com Disclosure Number: IPCOM000061847D
Original Publication Date: 1986-Sep-01
Included in the Prior Art Database: 2005-Mar-09

Publishing Venue

IBM

Related People

Authors:
Casey, DP Levy, LI [+details]

Abstract

Page operations on small systems require a large amount of processor and I/O overhead to maintain maps of pages in relation to the file system, such as PC DOS. In addition to tables relating virtual addresses to file record pointers, the file system overhead of mapping these records to an allocation table/directory requires additional seeks which are very costly. Other limitations, such as the present DOS being single-threaded, prevent other operations from taking place during paging operations. It is possible to directly map the disk allocations by using the virtual address as an index to the physical disk sectors so as to eliminate the need to use any file or disk operating system to maintain and calculate these allocations. Thus, conventional allocation tables, as well as the seeks to service these tables, are eliminated.