1. Generic term for a program t
hat assists in debugging ot
her programs by s
howing individual mac
hine instructions in a readable symbolic form and letting t
he user c
hange t
hem. In t
his sense t
he term DDT is now arc
haic,
having been widely displaced by "debugger" or names of individual programs like "
href="module.php?name=Lexikon&file=search&eid=1&query=adb">adb", "
href="module.php?name=Lexikon&file=search&eid=1&query=sdb">sdb", "
href="module.php?name=Lexikon&file=search&eid=1&query=dbx">dbx", or "
href="module.php?name=Lexikon&file=search&eid=1&query=gdb">gdb". 2. Under
href="module.php?name=Lexikon&file=search&eid=1&query=MIT">MIT' s fabled
href="module.php?name=Lexikon&file=search&eid=1&query=ITS">ITS href="module.php?name=Lexikon&file=search&eid=1&query=operating system">operating system, DDT (running under t
he alias
hACTRN) was also used as t
he
href="module.php?name=Lexikon&file=search&eid=1&query=shell">shell or top level command language used to execute ot
her programs. 3. Any one of several specific debuggers supported on early
href="module.php?name=Lexikon&file=search&eid=1&query=DEC">DEC hardware. T
he
href="module.php?name=Lexikon&file=search&eid=1&query=DEC">DEC href="module.php?name=Lexikon&file=search&eid=1&query=PDP-10">PDP-10 Reference
handbook (1969) contained a footnote on t
he first page of t
he documentation for DDT t
hat illuminates t
he origin of t
he term:
historical footnote: DDT was developed at
href="module.php?name=Lexikon&file=search&eid=1&query=MIT">MIT for t
he
href="module.php?name=Lexikon&file=search&eid=1&query=PDP-1">PDP-1 computer in 1961. At t
hat time DDT stood for "DEC Debugging Tape". Since t
hen, t
he idea of an on-line debugging program
has propagated t
hroug
hout t
he computer industry. DDT programs are now available for all DEC computers. Since media ot
her t
han tape are now frequently used, t
he more descriptive name "Dynamic Debugging Tec
hnique"
has been adopted, retaining t
he DDT abbreviation. Confusion between DDT-10 and anot
her well known pesticide, dic
hloro-dip
henyl-tric
hloroet
hane (C14-
h9-Cl5) s
hould be minimal since eac
h attacks a different, and apparently mutually exclusive, class of bugs. (T
he "tape" referred to was, incidentally, not magnetic but paper.) Sadly, t
his quotation was removed from later editions of t
he
handbook after t
he
href="module.php?name=Lexikon&file=search&eid=1&query=suit">suits took over and DEC became muc
h more "businesslike". T
he
history above is known to many old-time
hackers. But t
here' s more: Peter Samson, compiler of t
he original
href="module.php?name=Lexikon&file=search&eid=1&query=TMRC">TMRC lexicon, reports t
hat
he named "DDT" after a similar tool on t
he
href="module.php?name=Lexikon&file=search&eid=1&query=TX-0">TX-0 computer, t
he direct ancestor of t
he PDP-1 built at
href="module.php?name=Lexikon&file=search&eid=1&query=MIT">MIT' s Lincoln Lab in 1957. T
he debugger on t
hat ground-breaking mac
hine (t
he first transistorised computer) rejoiced in t
he name FLIT (FLexowriter Interrogation Tape). [
href="module.php?name=Lexikon&file=search&eid=1&query=Jargon File">Jargon File]
In addition suitable contents:
[ href="module.php?name=Lexikon&op=content&tid=31">2 ] [ href="module.php?name=Lexikon&op=content&tid=134">= ] [ href="module.php?name=Lexikon&op=content&tid=154">abbrev ] [ href="module.php?name=Lexikon&op=content&tid=234">ACT ] [ href="module.php?name=Lexikon&op=content&tid=262">ad ] [ href="module.php?name=Lexikon&op=content&tid=383">af ] [ href="module.php?name=Lexikon&op=content&tid=396">ag ] [ href="module.php?name=Lexikon&op=content&tid=411">ai ] [ href="module.php?name=Lexikon&op=content&tid=433">al ] [ href="module.php?name=Lexikon&op=content&tid=544">am ] [ href="module.php?name=Lexikon&op=content&tid=592">an ] [ href="module.php?name=Lexikon&op=content&tid=683">app ] [ href="module.php?name=Lexikon&op=content&tid=740">ar ] [ href="module.php?name=Lexikon&op=content&tid=743">arc ] [ href="module.php?name=Lexikon&op=content&tid=759">arg ] [ href="module.php?name=Lexikon&op=content&tid=800">as ] [ href="module.php?name=Lexikon&op=content&tid=894">at ] [ href="module.php?name=Lexikon&op=content&tid=996">av ] [ href="module.php?name=Lexikon&op=content&tid=1025">B ] [ href="module.php?name=Lexikon&op=content&tid=1026">b ] [ href="module.php?name=Lexikon&op=content&tid=1159">bb ] [ href="module.php?name=Lexikon&op=content&tid=1181">be ] [ href="module.php?name=Lexikon&op=content&tid=1444">bo ] [ href="module.php?name=Lexikon&op=content&tid=1535">br ] [ href="module.php?name=Lexikon&op=content&tid=1562">break ] [ href="module.php?name=Lexikon&op=content&tid=1672">bus ] [ href="module.php?name=Lexikon&op=content&tid=1695">by ] [ href="module.php?name=Lexikon&op=content&tid=1708">C ] [ href="module.php?name=Lexikon&op=content&tid=1724">ca ] [ href="module.php?name=Lexikon&op=content&tid=2001">ch ] [ href="module.php?name=Lexikon&op=content&tid=2099">ci ] [ href="module.php?name=Lexikon&op=content&tid=2136">ck ] [ href="module.php?name=Lexikon&op=content&tid=2138">cl ] [ href="module.php?name=Lexikon&op=content&tid=2145">class ] [ href="module.php?name=Lexikon&op=content&tid=2247">co ] [ href="module.php?name=Lexikon&op=content&tid=2330">com ] [ href="module.php?name=Lexikon&op=content&tid=2342">comma ] [ href="module.php?name=Lexikon&op=content&tid=2343">command ] [ href="module.php?name=Lexikon&op=content&tid=2429">compiler ] [ href="module.php?name=Lexikon&op=content&tid=2491">computer ] [ href="module.php?name=Lexikon&op=content&tid=2545">con ] [ href="module.php?name=Lexikon&op=content&tid=2791">cr ] [ href="module.php?name=Lexikon&op=content&tid=2888">CT ] [ href="module.php?name=Lexikon&op=content&tid=2900">cu ] [ href="module.php?name=Lexikon&op=content&tid=2976">D ] [ href="module.php?name=Lexikon&op=content&tid=3135">DD ] [ href="module.php?name=Lexikon&op=content&tid=3151">de ] [ href="module.php?name=Lexikon&op=content&tid=3165">deb ] [ href="module.php?name=Lexikon&op=content&tid=3175">debugging ] [ href="module.php?name=Lexikon&op=content&tid=3176">DEC ] [ href="module.php?name=Lexikon&op=content&tid=3371">diff ] [ href="module.php?name=Lexikon&op=content&tid=3565">do ] [ href="module.php?name=Lexikon&op=content&tid=3568">doc ] [ href="module.php?name=Lexikon&op=content&tid=3573">document ] [ href="module.php?name=Lexikon&op=content&tid=3574">documentation ] [ href="module.php?name=Lexikon&op=content&tid=3657">DP ] [ href="module.php?name=Lexikon&op=content&tid=3752">du ] [ href="module.php?name=Lexikon&op=content&tid=3754">dual ] [ href="module.php?name=Lexikon&op=content&tid=3834">E ] [ href="module.php?name=Lexikon&op=content&tid=3865">ec ] [ href="module.php?name=Lexikon&op=content&tid=3896">ed ] [ href="module.php?name=Lexikon&op=content&tid=3929">ee ] [ href="module.php?name=Lexikon&op=content&tid=4148">er ] [ href="module.php?name=Lexikon&op=content&tid=4150">era ] [ href="module.php?name=Lexikon&op=content&tid=4171">es ] [ href="module.php?name=Lexikon&op=content&tid=4199">et ] [ href="module.php?name=Lexikon&op=content&tid=4273">excl ] [ href="module.php?name=Lexikon&op=content&tid=4279">exec ] [ href="module.php?name=Lexikon&op=content&tid=4284">execute ] [ href="module.php?name=Lexikon&op=content&tid=4497">fi ] [ href="module.php?name=Lexikon&op=content&tid=4520">file ] [ href="module.php?name=Lexikon&op=content&tid=4606">FL ] [ href="module.php?name=Lexikon&op=content&tid=4646">FLI ] [ href="module.php?name=Lexikon&op=content&tid=4700">fo ] [ href="module.php?name=Lexikon&op=content&tid=4727">for ] [ href="module.php?name=Lexikon&op=content&tid=4828">fr ] [ href="module.php?name=Lexikon&op=content&tid=4967">fusion ] [ href="module.php?name=Lexikon&op=content&tid=4983">G ] [ href="module.php?name=Lexikon&op=content&tid=4989">ga ] [ href="module.php?name=Lexikon&op=content&tid=5026">gate ] [ href="module.php?name=Lexikon&op=content&tid=5027">gated ] [ href="module.php?name=Lexikon&op=content&tid=5049">gd ] [ href="module.php?name=Lexikon&op=content&tid=5057">ge ] [ href="module.php?name=Lexikon&op=content&tid=5134">gh ] [ href="module.php?name=Lexikon&op=content&tid=5141">gi ] [ href="module.php?name=Lexikon&op=content&tid=5205">gn ] [ href="module.php?name=Lexikon&op=content&tid=5291">gr ] [ href="module.php?name=Lexikon&op=content&tid=5390">gs ] [ href="module.php?name=Lexikon&op=content&tid=5403">gu ] [ href="module.php?name=Lexikon&op=content&tid=5434">h ] [ href="module.php?name=Lexikon&op=content&tid=5438">hack ] [ href="module.php?name=Lexikon&op=content&tid=5443">hacker ] [ href="module.php?name=Lexikon&op=content&tid=5493">hang ] [ href="module.php?name=Lexikon&op=content&tid=5512">hardware ] [ href="module.php?name=Lexikon&op=content&tid=5540">hat ] [ href="module.php?name=Lexikon&op=content&tid=5663">history ] [ href="module.php?name=Lexikon&op=content&tid=5681">hn ] [ href="module.php?name=Lexikon&op=content&tid=5768">hr ] [ href="module.php?name=Lexikon&op=content&tid=5919">icon ] [ href="module.php?name=Lexikon&op=content&tid=5931">id ] [ href="module.php?name=Lexikon&op=content&tid=5986">iff ] [ href="module.php?name=Lexikon&op=content&tid=6013">il ] [ href="module.php?name=Lexikon&op=content&tid=6064">in ] [ href="module.php?name=Lexikon&op=content&tid=6068">inc ] [ href="module.php?name=Lexikon&op=content&tid=6413">io ] [ href="module.php?name=Lexikon&op=content&tid=6446">iq ] [ href="module.php?name=Lexikon&op=content&tid=6449">ir ] [ href="module.php?name=Lexikon&op=content&tid=6482">is ] [ href="module.php?name=Lexikon&op=content&tid=6557">IT ] [ href="module.php?name=Lexikon&op=content&tid=6558">it ] [ href="module.php?name=Lexikon&op=content&tid=6568">ITS ] [ href="module.php?name=Lexikon&op=content&tid=6589">J ] [ href="module.php?name=Lexikon&op=content&tid=6620">Jargon File ] [ href="module.php?name=Lexikon&op=content&tid=6681">jo ] [ href="module.php?name=Lexikon&op=content&tid=6789">ke ] [ href="module.php?name=Lexikon&op=content&tid=6822">ki ] [ href="module.php?name=Lexikon&op=content&tid=6861">kn ] [ href="module.php?name=Lexikon&op=content&tid=6918">la ] [ href="module.php?name=Lexikon&op=content&tid=6950">language ] [ href="module.php?name=Lexikon&op=content&tid=7023">ld ] [ href="module.php?name=Lexikon&op=content&tid=7091">Lex ] [ href="module.php?name=Lexikon&op=content&tid=7107">li ] [ href="module.php?name=Lexikon&op=content&tid=7146">Linc ] [ href="module.php?name=Lexikon&op=content&tid=7151">line ] [ href="module.php?name=Lexikon&op=content&tid=7399">ls ] [ href="module.php?name=Lexikon&op=content&tid=7410">lt ] [ href="module.php?name=Lexikon&op=content&tid=7415">lu ] [ href="module.php?name=Lexikon&op=content&tid=7441">ly ] [ href="module.php?name=Lexikon&op=content&tid=7457">M ] [ href="module.php?name=Lexikon&op=content&tid=7463">ma ] [ href="module.php?name=Lexikon&op=content&tid=7479">machine ] [ href="module.php?name=Lexikon&op=content&tid=7582">man ] [ href="module.php?name=Lexikon&op=content&tid=7932">mil ] [ href="module.php?name=Lexikon&op=content&tid=7992">MIT ] [ href="module.php?name=Lexikon&op=content&tid=8019">mm ] [ href="module.php?name=Lexikon&op=content&tid=8032">mo ] [ href="module.php?name=Lexikon&op=content&tid=8040">mod ] [ href="module.php?name=Lexikon&op=content&tid=8079">module ] [ href="module.php?name=Lexikon&op=content&tid=8167">mp ] [ href="module.php?name=Lexikon&op=content&tid=8228">ms ] [ href="module.php?name=Lexikon&op=content&tid=8258">mu ] [ href="module.php?name=Lexikon&op=content&tid=8384">N ] [ href="module.php?name=Lexikon&op=content&tid=8386">na ] [ href="module.php?name=Lexikon&op=content&tid=8397">named ] [ href="module.php?name=Lexikon&op=content&tid=8460">nc ] [ href="module.php?name=Lexikon&op=content&tid=8472">ne ] [ href="module.php?name=Lexikon&op=content&tid=8488">net ] [ href="module.php?name=Lexikon&op=content&tid=8622">nf ] [ href="module.php?name=Lexikon&op=content&tid=8627">ng ] [ href="module.php?name=Lexikon&op=content&tid=8630">ni ] [ href="module.php?name=Lexikon&op=content&tid=8672">nn ] [ href="module.php?name=Lexikon&op=content&tid=8675">no ] [ href="module.php?name=Lexikon&op=content&tid=8760">ns ] [ href="module.php?name=Lexikon&op=content&tid=8964">om ] [ href="module.php?name=Lexikon&op=content&tid=8988">on-line ] [ href="module.php?name=Lexikon&op=content&tid=9014">op ] [ href="module.php?name=Lexikon&op=content&tid=9061">operating system ] [ href="module.php?name=Lexikon&op=content&tid=9204">pa ] [ href="module.php?name=Lexikon&op=content&tid=9228">page ] [ href="module.php?name=Lexikon&op=content&tid=9306">parent ] [ href="module.php?name=Lexikon&op=content&tid=9430">PD ] [ href="module.php?name=Lexikon&op=content&tid=9445">PDP ] [ href="module.php?name=Lexikon&op=content&tid=9446">PDP-10 ] [ href="module.php?name=Lexikon&op=content&tid=9457">pe ] [ href="module.php?name=Lexikon&op=content&tid=9550">ph ] [ href="module.php?name=Lexikon&op=content&tid=9651">pl ] [ href="module.php?name=Lexikon&op=content&tid=9821">port ] [ href="module.php?name=Lexikon&op=content&tid=9908">pr ] [ href="module.php?name=Lexikon&op=content&tid=10023">program ] [ href="module.php?name=Lexikon&op=content&tid=10144">pt ] [ href="module.php?name=Lexikon&op=content&tid=10253">query ] [ href="module.php?name=Lexikon&op=content&tid=10364">rc ] [ href="module.php?name=Lexikon&op=content&tid=10385">re ] [ href="module.php?name=Lexikon&op=content&tid=10754">rl ] [ href="module.php?name=Lexikon&op=content&tid=10767">ro ] [ href="module.php?name=Lexikon&op=content&tid=10887">ru ] [ href="module.php?name=Lexikon&op=content&tid=10892">run ] [ href="module.php?name=Lexikon&op=content&tid=10918">S ] [ href="module.php?name=Lexikon&op=content&tid=11010">sc ] [ href="module.php?name=Lexikon&op=content&tid=11102">script ] [ href="module.php?name=Lexikon&op=content&tid=11128">sd ] [ href="module.php?name=Lexikon&op=content&tid=11150">se ] [ href="module.php?name=Lexikon&op=content&tid=11314">sh ] [ href="module.php?name=Lexikon&op=content&tid=11339">shell ] [ href="module.php?name=Lexikon&op=content&tid=11376">si ] [ href="module.php?name=Lexikon&op=content&tid=11525">sl ] [ href="module.php?name=Lexikon&op=content&tid=11651">so ] [ href="module.php?name=Lexikon&op=content&tid=11790">spec ] [ href="module.php?name=Lexikon&op=content&tid=11934">st ] [ href="module.php?name=Lexikon&op=content&tid=12109">struct ] [ href="module.php?name=Lexikon&op=content&tid=12133">su ] [ href="module.php?name=Lexikon&op=content&tid=12162">suit ] [ href="module.php?name=Lexikon&op=content&tid=12206">support ] [ href="module.php?name=Lexikon&op=content&tid=12246">sy ] [ href="module.php?name=Lexikon&op=content&tid=12312">system ] [ href="module.php?name=Lexikon&op=content&tid=12359">T ] [ href="module.php?name=Lexikon&op=content&tid=12409">tap ] [ href="module.php?name=Lexikon&op=content&tid=12410">tape ] [ href="module.php?name=Lexikon&op=content&tid=12588">th ] [ href="module.php?name=Lexikon&op=content&tid=12707">TM ] [ href="module.php?name=Lexikon&op=content&tid=12712">TMRC ] [ href="module.php?name=Lexikon&op=content&tid=12715">tn ] [ href="module.php?name=Lexikon&op=content&tid=12721">to ] [ href="module.php?name=Lexikon&op=content&tid=12736">tool ] [ href="module.php?name=Lexikon&op=content&tid=12787">tr ] [ href="module.php?name=Lexikon&op=content&tid=12815">transistor ] [ href="module.php?name=Lexikon&op=content&tid=12886">TS ] [ href="module.php?name=Lexikon&op=content&tid=12896">tt ] [ href="module.php?name=Lexikon&op=content&tid=12939">tw ] [ href="module.php?name=Lexikon&op=content&tid=12965">TX-0 ] [ href="module.php?name=Lexikon&op=content&tid=12986">ua ] [ href="module.php?name=Lexikon&op=content&tid=13008">ug ] [ href="module.php?name=Lexikon&op=content&tid=13030">um ] [ href="module.php?name=Lexikon&op=content&tid=13146">up ] [ href="module.php?name=Lexikon&op=content&tid=13175">us ] [ href="module.php?name=Lexikon&op=content&tid=13188">user ] [ href="module.php?name=Lexikon&op=content&tid=13252">va ] [ href="module.php?name=Lexikon&op=content&tid=13310">ve ] [ href="module.php?name=Lexikon&op=content&tid=13366">vi ] [ href="module.php?name=Lexikon&op=content&tid=13725">win ] [ href="module.php?name=Lexikon&op=content&tid=13864">write ] [ href="module.php?name=Lexikon&op=content&tid=13891">X ]