Quoting Rod Smallwood <rodsmallwood at btconnect.com>:
3. RSX as Our sex
Heheh the 6809 actually had a SEX mnemonic SignEXtend :)
As every UK hacker knew in the 1980s, 'you can have SEX with a Dragon,
but not with an Apple' (the Dragon has a 6809 CPU, the Apple ][ hjas
a 6502, of course).
I assume everyone here knows the story that the PDP11 sign extended
instruction was called SXT becuase the suits objected to it being called
SEX. And the possibly aporcryphal extension that the hackers got their
own back in the naming of the Failed UniBus Address Register in the
VAX11/780 -- only after manuals had been printed and shipped did the
suits realise what FUBAR stood for :-)
-tony