ill-behaved
1. [numerical analysis] Said of an algorithm or computational method that tends
to blow up because of accumulated roundoff error or poor convergence properties.
2. Software that bypasses the defined operating system interfaces to do things
(like screen, keyboard, and disk I/O) itself, often in a way that depends on the
hardware of the machine it is running on or which is nonportable or incompatible
with other pieces of software.
In the IBM PC/mess-dos world, there is a folk theorem (nearly true) to the
effect that (owing to gross inadequacies and performance penalties in the OS
interface) all interesting applications are ill-behaved.
See also bare metal. Opposite: well-behaved, compare PC-ism.
[Jargon File]
Nearby terms:
ILIAD « I-Link « ILISP « ill-behaved » ILLIAC
» Illiac IV » ILOC
ILLIAC
Assembly language for the ILLIAC computer. Listed in CACM 2(5):16, (May 1959)
p.16.
Nearby terms:
I-Link « ILISP « ill-behaved « ILLIAC »
Illiac IV » ILOC » Ilog Solver
Illiac IV
<computer> One of the most infamous supercomputers ever. It used early
ideas on SIMD (single instruction stream, multiple data streams). The project
started in 1965, it used 64 processors and a 13MHz clock. In 1976 it ran its
first sucessfull application. It had 1MB memory (64x16KB).
Its actual performance was 15 MFLOPS, it was estimated in initial predictions to
be 1000 MFLOPS. It totally failed as a computer, only a quarter of the fully
planned machine was ever built, costs escalated from the $8 million estimated in
1966 to $31 million by 1972, and the computer took three more years of
enginering before it was operational.
The only good it did was to push research forward a bit, leading way for
machines such as the Thinking Machines CM-1 and CM-2.
(1995-04-28)
Nearby terms:
ILISP « ill-behaved « ILLIAC « Illiac IV »
ILOC » Ilog Solver » image
|