(Old-style (mostly) MS-DOS x86 programming:)
To bang out data to a device using the OUTSB (no, there really is such a code, today's date notwithstanding) opcode. This is much faster than a loop on OUTB. Many devices had additional "control" (as opposed to data) ports; by writing appropriate values there you could get BLITs of your data – hence the name.

For instance, in the late 80s I programmed a Vista frame buffer (essentially a souped-up version of the more popular Targa board). Displaying an image requires a huge amount of OUTBs – 512x512 is a quarter of a megabyte, no mean feat on a 80286. Replacing a loop on OUTBs (for each pixel) with a loop on OUTBSs (for each scan line) resulted in a huge speedup. Think of it as the ultimate in loop unrolling, and you begin to get the picture.

More modern techniques based on the intercalation design pattern will, of course, frown upon such low-level hackery. It does, however, retain its rightful place in the low levels of appropriate systems.

Out*bleat" (?), v. t.

To surpass in bleating.


© Webster 1913.

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