EP0217068A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of emulating the instructions of a target computer
Assignee: International Business Machines Corp
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Filing: 1986-08-05
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Granted: —
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Expires: 2006-08-05
Abstract
Abstract A method of emulating the instructions of a target computer in the instructions of a host computer to operate the host computer in accordance with the target computer instructions, the target computer having the capability of modifying its own instructions and data during operation comprising the steps of constructing a template of the host instructions for each of the target instructions, storing each of the templates for reuse each time the corresponding target instruction is to be executed, limiting access to the stored templates to permit only read operations to be performed thereon, and detecting a target instruction which attempts a write operation on one of the stored templates.
Inventors
- 👤 Richard O. Simpson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 06:02
CPC Classifications
G; G06; G06F; G06F9/00; G06F9/06; G06F9/44; G06F9/455; G06F9/45504
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
99 words
A method of emulating the instructions of a target computer in the instructions of a host computer to operate said host computer in accordance with said target computer instructions, said target computer having the capability of modifying its own instructions and data during operation, said method comprising the steps of: constructing a template of said host instructions performing the function of each of said target instructions; storing each of said templates for reuse each time the corresponding target instruction is to be executed; and limiting access to said stored templates to permit only read operations to be performed thereon.
Claim 2
Independent Claim
99 words
A method of emulating the instructions of a target computer in the instructions of a host computer to operate said host computer in accordance with said target computer instructions, said target computer having the capability of modifying its own instructions and data during operation, said method comprising the steps of: constructing a template of said host instructions performing the function of each of said target instructions; storing each of said templates for reuse each time the corresponding target instruction is to be executed; and limiting access to said stored templates to permit only read operations to be performed thereon.
Claim 3
Dependent Claim
26 words
A method in accordance with Claim 1 including the step of detecting a target instruction which attempts a write operation on one of said stored templates.
Claim 4
Dependent Claim
40 words
A method in accordance with Claim 1 or 2 including the step of generating a program interrupt of said host computer in response to detection of a target instruction which attempts a write operation on one of said stored templates.
Claim 5
Dependent Claim
27 words
A method in accordance with Claim 3 including the step of examining said target instruction which generated said interrupt to determine its effect on said stored template.
Claim 6
Dependent Claim
31 words
A method in accordance with Claim 4 including the step of erasing said stored template after examining said target instruction and determining that said target instruction would modify said stored template.
Claim 7
Dependent Claim
27 words
A method in accordance with Claim 5 including the step of executing said target instruction which generated said program interrupt to create a new template for storage.
Claim 8
Dependent Claim
39 words
A method in accordance with Claim 4 including the step of executing said target instruction which generated said program interrupt if it is determined that execution of said target instruction will not affect the contents of said stored template.
Claim 9
Independent Claim
35 words
A method in accordance with any one of the preceding claims further including the step of initially storing said target instructions in a target memory which permits both reading and writing of said target instructions.
Claim 10
Independent Claim
34 words
A method in accordance with any one of the preceding claims including the step of inserting at least one lock bit in each of said stored templates to permit only reading of said templates.
Claim 11
Dependent Claim
24 words
A method in accordance with Claim 9 including the step of inserting one of said lock bits in each line of said stored templates.
References Cited (Backward Citations)
No citation records indexed.
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