64 bit: what changed
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| 1 | + | A **64-bit** processor is one that generally supports a word size of 264, where the constant "[[maxint]]" has the value 264-1, or 18,446,744,073,709,551,615. The signed version of this number can express a range of -18,446,744,073,709,551,615..0 and 0..18,446,744,073,709,551,615. The unsigned version of this number can express a range of 0..18,446,744,073,709,551,616. It also means that programs and data spaces can be much larger than on the older 32-bit and 16-bit machines. | |
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| 3 | + | Examples of 32-bit processors include | |
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| 5 | + | * Newer versions of the X86 microcomputer, Itanium and newer, AMD64 (WINTEL architecture) | |
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| 7 | + | Currently, 64-bit processors (X86) are enhancements of 32-bit processors, and generally can run 32-bit and 16-bit applications. The reverse, however, is not true; 64-bit code cannot run on a machine smaller than 64 bits. | |
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| 9 | 9 | ## See Also | |
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| 11 | + | * [[Writing portable code regarding the processor architecture]] | |
| 12 | + | * [[Integer]] | |
| 13 | + | * [[32 bit]] | |
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| 15 | 15 | --- | |
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| 16 | + | *From the Free Pascal wiki, page "64 bit", as the Internet Archive kept it on 2023-01-30. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).* |