bit bang n.
Transmission of data on a serial line, when
accomplished by rapidly tweaking a single output bit, in software,
at the appropriate times. The technique is a simple loop with
eight OUT and SHIFT instruction pairs for each byte. Input is more
interesting. And full duplex (doing input and output at the same
time) is one way to separate the real hackers from the
wannabees.
Bit bang was used on certain early models of Prime computers,
presumably when UARTs were too expensive, and on archaic Z80 micros
with a Zilog PIO but no SIO. In an interesting instance of the
cycle of reincarnation, this technique returned to use in the
early 1990s on some RISC architectures because it consumes such
an infinitesimal part of the processor that it actually makes sense
not to have a UART. Compare cycle of reincarnation.
Transmission of data on a serial line, when
accomplished by rapidly tweaking a single output bit, in software,
at the appropriate times. The technique is a simple loop with
eight OUT and SHIFT instruction pairs for each byte. Input is more
interesting. And full duplex (doing input and output at the same
time) is one way to separate the real hackers from the
wannabees.
Bit bang was used on certain early models of Prime computers,
presumably when UARTs were too expensive, and on archaic Z80 micros
with a Zilog PIO but no SIO. In an interesting instance of the
cycle of reincarnation, this technique returned to use in the
early 1990s on some RISC architectures because it consumes such
an infinitesimal part of the processor that it actually makes sense
not to have a UART. Compare cycle of reincarnation.
Related:
- bit bang: n. Transmission of data on a serial line,
when accomplished by rapidly tweaking a single output... - software rot n.
Term used to describe the tendency of
software that has not been used in a while to lose;
such failure may be semi-humorously ascribed to... - cycle of reincarnation: [coined by Ivan Sutherland ca.
1970] n. Term used to refer to a well-known effect... - bit bucket n.
[very common] 1. The universal data sink
(originally,
the mythical receptacle used to catch bits when they... - blitter: /blit'r/ n. A special-purpose chip or hardware system
built to perform {blit} operations,
esp. used for fast implementation of bit-mapped... - bit-paired keyboard n.,obs.
(alt. `bit-shift
keyboard') A non-standard keyboard layout that seems to have
originated with the Teletype ASR-33 and remained common for several
years on early computer equipment.
The ASR-33 was a mechanical device (see EOU), so... - wheel of reincarnation
[coined in a paper by T.
H. Myer and I.E. Sutherland "On the Design of Display... - clocks: n. Processor logic cycles, so called because each
generally corresponds to one clock pulse in the processor's timing.
The relative execution times of instructions on a machine... - PDP-10: [Programmed Data Processor model 10] n. The machine that
made timesharing real.
It looms large in hacker folklore because of its...
