Instruction set architecture
set of abstract symbols (called instructions) which identify and describe operations in a computer program to a computer processor
An instruction set architecture (ISA) is an abstract model that defines the programmable interface of the CPU of a computer, defining how software interacts with hardware. A device (i.e. CPU) that interprets instructions described by an ISA is an implementation of that ISA. Generally, the same ISA is used for a family of related CPU devices.
In general, an ISA defines the instructions, data types, registers, and the programming interface for managing main memory such as addressing modes, virtual memory, and memory consistency mechanisms. The ISA also includes the input/output model of the programmable interface.
An ISA specifies the behavior implied by machine code running on an implementation of that ISA in a fashion that does not depend on the characteristics of that implementation, providing binary compatibility between implementations. This enables multiple implementations of an ISA that differ in characteristics such as performance, physical size, and monetary cost (among other things), but that are capable of running the same machine code, so that a lower-performance, lower-cost machine can be replaced with a higher-cost, higher-performance machine without having to replace software. It also enables the evolution of the microarchitectures of the implementations of that ISA, so that a newer, higher-performance implementation of an ISA can run software that runs on previous generations of implementations.
If an operating system maintains a standard and compatible application binary interface (ABI) for a particular ISA, machine code will run on future implementations of that ISA and operating system. However, if an ISA supports running multiple operating systems, it does not guarantee that machine code for one operating system will run on another operating system, unless the first operating system supports running machine code built for the other operating system.
This brief starts where responsible research should: with the source description of “Instruction set architecture” as set of abstract symbols (called instructions) which identify and describe operations in a computer program to a computer processor. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the general reference register because the source frames it as set of abstract symbols (called instructions) which identify and describe operations in a computer program to a computer processor. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Aug 29, 2026. The linked authority identifier is Q272683. None of the 0 selected statements returned an explicit reference.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Instruction set architecture”, its source revision and the description used here.
- Expand the search: follow Instruction set architecture primary sources, Instruction set architecture archive and Instruction research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Instruction set architecture”?
- Which cited source is closest to the event, object or claim?
- What terminology or title could unlock a more precise catalogue search?
Search terms from this dossier
This entry incorporates text from “Instruction set architecture” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.