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Why DDT?

Bill Costa
Just another Perl hacker.
・2 min read

For many years I've been in the habit of naming my debugging flag variable 'DDT'. It recently occurred to me that many programmers today, looking at my code, would not get the joke. So why DDT?

  1. Dichlorodiphenyltrichloroethane (DDT) was developed as the first of
    the modern synthetic insecticides in the 1940s. It was initially
    used with great effect to combat insect pests and became a well
    known, and later notorious, insecticide.

  2. From Wikipedia:

Dynamic Debugging Technique (DDT) is a series of debugger programs
originally developed for Digital Equipment Corporation (DEC)
hardware, initially known as DEC Debugging Tape because it was
distributed on paper tape. The name is a pun on the insecticide
DDT. The first version of DDT was developed at MIT for the PDP-1
computer in 1961, but newer versions on newer platforms continued
to use the same name. After being ported to other vendor's
platforms and changing media, the name was changed to the less
DEC-centric version. Early versions of Digital Research's CP/M and
CP/M-86 kept the DEC name DDT (and DDT-86 and DDT-68K) for their
debugger, however, now meaning "Dynamic Debugging Tool".

I used DEC's DDT program briefly in the early 80's on the university's DEC-10 mainframe to debug assembly language programs. So to this day I still like the pun.

PS: While I never got to use the original DDT from paper tape, I did use paper tape in college (mid-70's) for storing my BASIC language programs.

Yeah, I'm that old.

PPS: DDT is a very effective, if dangerous, insecticide, leading some to observe that the acronym should actually stand for Drop Dead Twice.

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