Emulation of a data processing system
US4727480A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 1984 |
| Grant date | Feb 23, 1988 |
| Priority date | — |
| Expiry date | Jul 9, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/105
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Emulation method and apparatus allowing a first system, which is not designed as a functional duplicate of a second system, to emulate the second system. The input/output structure of the second system is emulated in the first system by means of routines stored therein and which direct the already existing input/output structure to operate in the same manner as the input/output structure of the second system. The emulation routines are in turn invoked through the non-maskable interrupt mechanism of the first system by a modification thereto which detects the occurrence of "foreign" input/output requests; that is, input/output requests occuring in programs originally written for the second system and which are not normally recognized by the first system. The means for detecting foreign input/output requests includes means for comparing input/output request port addresses to the range of port addresses occupied by the system input/output devices and indicating when a port address is within the range of address space occupied by the system input/output devices. The foreign request detection means generates a non-maskable interrupt to invoke an input/output emulation routine upon the o…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.