RISC OS filetype
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| − | '''RISC OS filetype''', or '''Acorn filetype''', is a system of 12-bit file type identifiers used on RISC OS. It is essentially the RISC OS equivalent of a [[ | + | '''RISC OS filetype''', or '''Acorn filetype''', is a system of 12-bit file type identifiers used on RISC OS. It is essentially the RISC OS equivalent of a [[filename extension]]. A filetype is usually written as three hexadecimal characters, like "FF9". |
== Format details == | == Format details == | ||
| − | A number of RISC OS archive formats have a 32-bit "load address" | + | A number of RISC OS archive formats have a 32-bit "load address" field. If the three high nibbles of this field are all 0xf, then the next three nibbles contain the filetype.[https://www.riscosopen.org/wiki/documentation/show/FileSwitch%20Key%20Features#load_execution] Formats that have such a field include [[ArcFS]], [[Spark]], [[Squash (RISC OS)|Squash]], and [[ZIP]] (in extra field #0x4341). |
Sometimes, when a RISC OS file is transferred to a foreign system, its filetype is appended to the filename, separated with a comma. | Sometimes, when a RISC OS file is transferred to a foreign system, its filetype is appended to the filename, separated with a comma. | ||
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[[Category:Naming and numbering systems]] | [[Category:Naming and numbering systems]] | ||
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[[Category:RISC OS]] | [[Category:RISC OS]] | ||
Latest revision as of 20:50, 10 January 2020
RISC OS filetype, or Acorn filetype, is a system of 12-bit file type identifiers used on RISC OS. It is essentially the RISC OS equivalent of a filename extension. A filetype is usually written as three hexadecimal characters, like "FF9".
[edit] Format details
A number of RISC OS archive formats have a 32-bit "load address" field. If the three high nibbles of this field are all 0xf, then the next three nibbles contain the filetype.[1] Formats that have such a field include ArcFS, Spark, Squash, and ZIP (in extra field #0x4341).
Sometimes, when a RISC OS file is transferred to a foreign system, its filetype is appended to the filename, separated with a comma.
