Object code

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Object code, or executable binary (sometimes shortened to plain 'binary') is a program in the low-level form which a computer's CPU hardware can execute directly; i.e. instructions for the CPU to execute. (The specification shared by the members of a CPU family for their object code is now called its instruction set architecture; CPUs which can execute the same object code are said to be program compatible.)

To run it, all that need be done is read the program's instructions into main memory from wherever it is stored, and tell the CPU to start executing it.

A given program's object code is usually set up to be loaded in main memory at a given location; if it is loaded elsewhere, it usually cannot function - although this depends on the details of a particular CPU, as some supported location-independent code, which could be loaded and run at any address.

It is now usually stored on disk, although historically it was stored on a long list of types of media, including paper tape, punched cards, and magnetic tape.

On older computers with front panels, it was possible to 'toggle in' progams (i.e. deposit the words of the program directly into main memory, using the switches on the front console).

See also