DDT /D-D-T/ n.
[from the insecticide para-dichloro-diphenyl-trichloroethene]
1. Generic term for a program that assists in debugging other
programs by showing individual machine instructions in a readable
symbolic form and letting the user change them. In this sense the
term DDT is now archaic, having been widely displaced by
`debugger' or names of individual programs like adb,
sdb, dbx, or gdb. 2. [ITS]
Under MIT's fabled ITS operating
system, DDT (running under the alias HACTRN, a six-letterism for
`Hack Translator') was also used as the shell or top level command language used to
execute other programs. 3. Any one of several specific DDTs
(sense 1) supported on early DEC
hardware and CP/M. The PDP-10 Reference Handbook (1969) contained
a footnote on the first page of the documentation for DDT that
illuminates the origin of the term:
Historical footnote: DDT was developed at MIT for the
PDP-1 computer in 1961. At that time DDT stood for "DEC Debugging
Tape". Since then, the idea of an on-line debugging program has
propagated throughout the computer industry. DDT programs are now
available for all DEC computers. Since media other than tape are
now frequently used, the more descriptive name "Dynamic Debugging
Technique" has been adopted, retaining the DDT abbreviation.
Confusion between DDT-10 and another well known pesticide,
dichloro-diphenyl-trichloroethane (C14-H9-Cl5) should be minimal
since each attacks a different, and apparently mutually
exclusive, class of bugs.
(The `tape' referred to was, incidentally, not magnetic but
paper.) Sadly, this quotation was removed from later editions of
the handbook after the suits took over
and DEC became much more
`businesslike'.
The history above is known to many old-time hackers. But
there's more: Peter Samson, compiler of the original TMRC lexicon, reports that he named `DDT' after a
similar tool on the TX-0 computer, the direct ancestor of the
PDP-1 built at MIT's Lincoln Lab in 1957. The debugger on that
ground-breaking machine (the first transistorized computer)
rejoiced in the name FLIT (FLexowriter Interrogation Tape).
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de-rezz /dee-rez'/
[from `de-resolve' via the movie "Tron"] (also `derez') 1. vi.
To disappear or dissolve; the image that goes with it is of an
object breaking up into raster lines and static and then
dissolving. Occasionally used of a person who seems to have
suddenly `fuzzed out' mentally rather than physically. Usage:
extremely silly, also rare. This verb was actually invented as
fictional hacker jargon, and adopted in a spirit of
irony by real hackers years after the fact. 2. vt. The Macintosh
resource decompiler. On a Macintosh, many program structures
(including the code itself) are managed in small segments of the
program file known as `resources'; `Rez' and `DeRez' are a pair
of utilities for compiling and decompiling resource files. Thus,
decompiling a resource is `derezzing'. Usage: very common.