2014-04-26 10:52:28 -04:00
|
|
|
DDT
|
|
|
|
|
|
2014-04-26 11:54:15 -04:00
|
|
|
/DDT/ , 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 C 14 H 9 Cl 5 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
|
2014-07-26 03:53:53 -04:00
|
|
|
handbook after the suits took over and DEC became much more businesslike.
|
2014-04-26 11:54:15 -04:00
|
|
|
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). Flit was for many years the trade-name of
|
|
|
|
|
a popular insecticide.
|
