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 "ref="module.php?name=Lexikon&file=search&eid=1&query=adb">adb", "ref="module.php?name=Lexikon&file=search&eid=1&query=sdb">sdb", "ref="module.php?name=Lexikon&file=search&eid=1&query=dbx">dbx", or "ref="module.php?name=Lexikon&file=search&eid=1&query=gdb">gdb". 2. Under ref="module.php?name=Lexikon&file=search&eid=1&query=MIT">MIT' s fabled ref="module.php?name=Lexikon&file=search&eid=1&query=ITS">ITS ref="module.php?name=Lexikon&file=search&eid=1&query=operating system">operating system, DDT (running under the alias HACTRN) was also used as the ref="module.php?name=Lexikon&file=search&eid=1&query=shell">shell or top level command language used to execute other programs. 3. Any one of several specific debuggers supported on early ref="module.php?name=Lexikon&file=search&eid=1&query=DEC">DEC hardware. The ref="module.php?name=Lexikon&file=search&eid=1&query=DEC">DEC ref="module.php?name=Lexikon&file=search&eid=1&query=PDP-10">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 ref="module.php?name=Lexikon&file=search&eid=1&query=MIT">MIT for the ref="module.php?name=Lexikon&file=search&eid=1&query=PDP-1">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 ref="module.php?name=Lexikon&file=search&eid=1&query=suit">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 ref="module.php?name=Lexikon&file=search&eid=1&query=TMRC">TMRC lexicon, reports that he named "DDT" after a similar tool on the ref="module.php?name=Lexikon&file=search&eid=1&query=TX-0">TX-0 computer, the direct ancestor of the PDP-1 built at ref="module.php?name=Lexikon&file=search&eid=1&query=MIT">MIT' s Lincoln Lab in 1957. The debugger on that ground-breaking machine (the first transistorised computer) rejoiced in the name FLIT (FLexowriter Interrogation Tape). [ref="module.php?name=Lexikon&file=search&eid=1&query=Jargon File">Jargon File]

In addition suitable contents:
[ ref="module.php?name=Lexikon&op=content&tid=31">2 ] [ ref="module.php?name=Lexikon&op=content&tid=134">= ] [ ref="module.php?name=Lexikon&op=content&tid=154">abbrev ] [ ref="module.php?name=Lexikon&op=content&tid=234">ACT ] [ ref="module.php?name=Lexikon&op=content&tid=262">ad ] [ ref="module.php?name=Lexikon&op=content&tid=383">af ] [ ref="module.php?name=Lexikon&op=content&tid=396">ag ] [ ref="module.php?name=Lexikon&op=content&tid=411">ai ] [ ref="module.php?name=Lexikon&op=content&tid=433">al ] [ ref="module.php?name=Lexikon&op=content&tid=544">am ] [ ref="module.php?name=Lexikon&op=content&tid=592">an ] [ ref="module.php?name=Lexikon&op=content&tid=683">app ] [ ref="module.php?name=Lexikon&op=content&tid=740">ar ] [ ref="module.php?name=Lexikon&op=content&tid=743">arc ] [ ref="module.php?name=Lexikon&op=content&tid=759">arg ] [ ref="module.php?name=Lexikon&op=content&tid=800">as ] [ ref="module.php?name=Lexikon&op=content&tid=894">at ] [ ref="module.php?name=Lexikon&op=content&tid=996">av ] [ ref="module.php?name=Lexikon&op=content&tid=1025">B ] [ ref="module.php?name=Lexikon&op=content&tid=1026">b ] [ ref="module.php?name=Lexikon&op=content&tid=1159">bb ] [ ref="module.php?name=Lexikon&op=content&tid=1181">be ] [ ref="module.php?name=Lexikon&op=content&tid=1444">bo ] [ ref="module.php?name=Lexikon&op=content&tid=1535">br ] [ ref="module.php?name=Lexikon&op=content&tid=1562">break ] [ ref="module.php?name=Lexikon&op=content&tid=1672">bus ] [ ref="module.php?name=Lexikon&op=content&tid=1695">by ] [ ref="module.php?name=Lexikon&op=content&tid=1708">C ] [ ref="module.php?name=Lexikon&op=content&tid=1724">ca ] [ ref="module.php?name=Lexikon&op=content&tid=2001">ch ] [ ref="module.php?name=Lexikon&op=content&tid=2099">ci ] [ ref="module.php?name=Lexikon&op=content&tid=2136">ck ] [ ref="module.php?name=Lexikon&op=content&tid=2138">cl ] [ ref="module.php?name=Lexikon&op=content&tid=2145">class ] [ 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ref="module.php?name=Lexikon&op=content&tid=5205">gn ] [ ref="module.php?name=Lexikon&op=content&tid=5291">gr ] [ ref="module.php?name=Lexikon&op=content&tid=5390">gs ] [ ref="module.php?name=Lexikon&op=content&tid=5403">gu ] [ ref="module.php?name=Lexikon&op=content&tid=5434">h ] [ ref="module.php?name=Lexikon&op=content&tid=5438">hack ] [ ref="module.php?name=Lexikon&op=content&tid=5443">hacker ] [ ref="module.php?name=Lexikon&op=content&tid=5493">hang ] [ ref="module.php?name=Lexikon&op=content&tid=5512">hardware ] [ ref="module.php?name=Lexikon&op=content&tid=5540">hat ] [ ref="module.php?name=Lexikon&op=content&tid=5663">history ] [ ref="module.php?name=Lexikon&op=content&tid=5681">hn ] [ ref="module.php?name=Lexikon&op=content&tid=5768">hr ] [ ref="module.php?name=Lexikon&op=content&tid=5919">icon ] [ ref="module.php?name=Lexikon&op=content&tid=5931">id ] [ ref="module.php?name=Lexikon&op=content&tid=5986">iff ] [ ref="module.php?name=Lexikon&op=content&tid=6013">il ] [ ref="module.php?name=Lexikon&op=content&tid=6064">in ] [ ref="module.php?name=Lexikon&op=content&tid=6068">inc ] [ ref="module.php?name=Lexikon&op=content&tid=6413">io ] [ ref="module.php?name=Lexikon&op=content&tid=6446">iq ] [ ref="module.php?name=Lexikon&op=content&tid=6449">ir ] [ ref="module.php?name=Lexikon&op=content&tid=6482">is ] [ ref="module.php?name=Lexikon&op=content&tid=6557">IT ] [ ref="module.php?name=Lexikon&op=content&tid=6558">it ] [ ref="module.php?name=Lexikon&op=content&tid=6568">ITS ] [ ref="module.php?name=Lexikon&op=content&tid=6589">J ] [ ref="module.php?name=Lexikon&op=content&tid=6620">Jargon File ] [ ref="module.php?name=Lexikon&op=content&tid=6681">jo ] [ ref="module.php?name=Lexikon&op=content&tid=6789">ke ] [ ref="module.php?name=Lexikon&op=content&tid=6822">ki ] [ ref="module.php?name=Lexikon&op=content&tid=6861">kn ] [ ref="module.php?name=Lexikon&op=content&tid=6918">la ] [ ref="module.php?name=Lexikon&op=content&tid=6950">language ] [ ref="module.php?name=Lexikon&op=content&tid=7023">ld ] [ ref="module.php?name=Lexikon&op=content&tid=7091">Lex ] [ ref="module.php?name=Lexikon&op=content&tid=7107">li ] [ ref="module.php?name=Lexikon&op=content&tid=7146">Linc ] [ ref="module.php?name=Lexikon&op=content&tid=7151">line ] [ ref="module.php?name=Lexikon&op=content&tid=7399">ls ] [ ref="module.php?name=Lexikon&op=content&tid=7410">lt ] [ ref="module.php?name=Lexikon&op=content&tid=7415">lu ] [ ref="module.php?name=Lexikon&op=content&tid=7441">ly ] [ ref="module.php?name=Lexikon&op=content&tid=7457">M ] [ ref="module.php?name=Lexikon&op=content&tid=7463">ma ] [ ref="module.php?name=Lexikon&op=content&tid=7479">machine ] [ ref="module.php?name=Lexikon&op=content&tid=7582">man ] [ ref="module.php?name=Lexikon&op=content&tid=7932">mil ] [ ref="module.php?name=Lexikon&op=content&tid=7992">MIT ] [ ref="module.php?name=Lexikon&op=content&tid=8019">mm ] [ ref="module.php?name=Lexikon&op=content&tid=8032">mo ] [ ref="module.php?name=Lexikon&op=content&tid=8040">mod ] [ ref="module.php?name=Lexikon&op=content&tid=8079">module ] [ ref="module.php?name=Lexikon&op=content&tid=8167">mp ] [ ref="module.php?name=Lexikon&op=content&tid=8228">ms ] [ ref="module.php?name=Lexikon&op=content&tid=8258">mu ] [ ref="module.php?name=Lexikon&op=content&tid=8384">N ] [ ref="module.php?name=Lexikon&op=content&tid=8386">na ] [ ref="module.php?name=Lexikon&op=content&tid=8397">named ] [ ref="module.php?name=Lexikon&op=content&tid=8460">nc ] [ ref="module.php?name=Lexikon&op=content&tid=8472">ne ] [ ref="module.php?name=Lexikon&op=content&tid=8488">net ] [ ref="module.php?name=Lexikon&op=content&tid=8622">nf ] [ ref="module.php?name=Lexikon&op=content&tid=8627">ng ] [ ref="module.php?name=Lexikon&op=content&tid=8630">ni ] [ ref="module.php?name=Lexikon&op=content&tid=8672">nn ] [ ref="module.php?name=Lexikon&op=content&tid=8675">no ] [ ref="module.php?name=Lexikon&op=content&tid=8760">ns ] [ ref="module.php?name=Lexikon&op=content&tid=8964">om ] [ ref="module.php?name=Lexikon&op=content&tid=8988">on-line ] [ ref="module.php?name=Lexikon&op=content&tid=9014">op ] [ ref="module.php?name=Lexikon&op=content&tid=9061">operating system ] [ ref="module.php?name=Lexikon&op=content&tid=9204">pa ] [ ref="module.php?name=Lexikon&op=content&tid=9228">page ] [ ref="module.php?name=Lexikon&op=content&tid=9306">parent ] [ ref="module.php?name=Lexikon&op=content&tid=9430">PD ] [ ref="module.php?name=Lexikon&op=content&tid=9445">PDP ] [ ref="module.php?name=Lexikon&op=content&tid=9446">PDP-10 ] [ ref="module.php?name=Lexikon&op=content&tid=9457">pe ] [ ref="module.php?name=Lexikon&op=content&tid=9550">ph ] [ ref="module.php?name=Lexikon&op=content&tid=9651">pl ] [ ref="module.php?name=Lexikon&op=content&tid=9821">port ] [ ref="module.php?name=Lexikon&op=content&tid=9908">pr ] [ ref="module.php?name=Lexikon&op=content&tid=10023">program ] [ 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