BLT
BLT: /B·L·T/, /bl@t/, /belt/, n.,vt. Synonym for blit. This is the original form
of blit and the ancestor of
bitblt. It referred to any large bit-field copy or
move operation (one resource-intensive memory-shuffling operation done on
pre-paged versions of ITS, WAITS, and TOPS-10 was sardonically referred to
as “The Big BLT”). The jargon usage has outlasted the
PDP-10 BLock Transfer instruction from which
BLT derives; nowadays, the assembler mnemonic
BLT almost always means “Branch if Less Than
zero”.
Courtesy of 'The Jargon File 4.4.7'
