SEX (computing)
49635
223840543
2008-07-06T02:30:38Z
J.delanoy
2372780
Reverted edits by [[Special:Contributions/122.53.115.188|122.53.115.188]] to last version by Livitup (using [[WP:HG|Huggle]])
: ''The acronym ''SEX'' (written in capital letters) redirects here. For other meanings, see [[Sex (disambiguation)]].''
In computing, the '''SEX''' [[assembly language]] [[mnemonic]] has often been used for the "<code>Sign EXtend</code>" machine [[instruction set|instruction]] found in the [[PDP-11]] and many other computer architectures.
==SEX as an assembly language mnemonic==
[[Digital Equipment Corporation|DEC]]'s engineers nearly got a [[PDP-11]] assembler (MACRO-11) that used the <code>SEX</code> mnemonic (for Sign EXtend) out the door at one time, however their marketing department forced them to change it to <code>SXT</code> before release.
The [[RCA 1802]] chip used in the early [[COSMAC ELF|ELF]] and [[ELF II]] microcomputers had a "<code>SEt X register</code>" instruction, but this seems to have had little [[folklore|folkloric]] impact, probably because of the 1802's very low market share in the general microcomputer field.
The [[Motorola 6809]], used in Radio Shack's [[TRS-80 Color Computer]] (in the US) and Dragon Data's [[Dragon 32/64]] home/personal computers (in the UK), actually had an official <code>SEX</code> instruction; the [[MOS Technology 6502|MOS 6502]] in the [[Apple II]] and the [[Commodore VIC-20]] with which it competed did not. This lead British [[Hacker (computing)|hackers]] to the observation that while you could have SEX with a [[western dragon|Dragon]], you could never have SEX with an Apple.{{Fact|date=March 2008}}
The author of ''The Intel 8086 Primer'', who was one of the original designers of the [[Intel 8086]], noted that there was originally a <code>SEX</code> instruction on that processor, too. He says that [[Intel]] management got cold feet and decreed that it be changed, and thus the instruction was renamed [[x86 instruction listings#x86 Integer Instructions|<code>CBW</code> and <code>CWD</code>]] (depending on what was being extended). The [[Intel 8048]] [[microcontroller]] (used e.g. in the original [[IBM PC keyboard]]) is also missing straight <code>SEX</code> but has [[logical disjunction|logical-or]] and [[logical conjunction|logical-and]] instructions <code>ORL</code> and <code>ANL</code>.
In NEC's [[SX architecture]], the <code>SEX</code> instruction stands for "Save EXecution counter". The Execution Counter increments once for every [[SX architecture|SX]] instruction executed.
==SEX in software: rarely used jargon==
The [[TLA]] '''SEX''' has humorously been said to stand for '''''S'''oftware '''EX'''change'', meaning copying of software. As [[file sharing]] has sometimes spread [[computer virus]]es, it has been stated that “illicit SEX can transmit viral diseases to your computer.”
==Other sightings==
The Commodore 64 Video Interface Chip (VIC) II contains registers to double the size of the hardware sprites in one or both directions. The register $d017 (Sprite EXpand Y) contains 1 bit per sprite to allow expansion in the Y direction, while $d01d (Sprite EXpand X) alters the X size in the same manner.
{{Jargon}}
[[Category:Machine code]]
[[Category:Computer jargon]]