Contents page

Index (83KB)

BLT

BLT: /B-L-T/, /bl*t/ or (rarely) /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'.