Method and apparatus for enabling address lines to access the high memory area
US6134577A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 1995 |
| Grant date | Oct 17, 2000 |
| Priority date | — |
| Expiry date | Jul 21, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0623
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for interfacing an application program with an operating system of a computer when the application program relies on a predetermined address line to be set in a low state during the initial stages of the application program's operation. The computer has a lower memory region, which is addressable when the predetermined address line is in a low state, and an upper memory region, which is addressable when the predetermined address line is in a high state. The method provides an operating system stub in the lower memory region of the computer and provides an operating system in the higher memory region of the computer. The stub receives each operating system call made by the application program. After receiving an operating system call, the operating system stub sets the predetermined address line to the high state if the predetermined address line is in the low state then invokes the operating system call. Upon return from the operating system call, the stub determines whether the application program has made more than a predetermined number of operating system calls. If the application program has not made more than a predetermined number of operating system calls, the stub…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.