BLT

1. /B-L-T/, /bl*t/ or (rarely) /belt/ Synonym for blit.

This is the original form of blit and the ancestor of

bitblt. It refers 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 assembly language

mnemonic BLT almost always means "Branch if Less Than

zero".

2. bacon, lettuce and tomato (sandwich).

[Jargon File]