The Collaborative International Dictionary of English v.0.48:

Di- \Di-\ [Gr. di`s- twice; akin to ? two, L. bis twice. See
   Two, and cf. Bi-, Dia-. The L. pref. dis- sometimes
   assumes the form di-. See Dis-.]
   A prefix, signifying twofold, double, twice; (Chem.) denoting
   two atoms, radicals, groups, or equivalents, as the case may
   be. See Bi-, 2. Dia

The Collaborative International Dictionary of English v.0.48:

Dia- \Di"a-\, Di- \Di-\ . [Gr. dia` through; orig., dividing
   into two parts; akin to ? two. See Two, and cf. 1st Di-.]
   A prefix denoting through; also, between, apart, asunder,
   across. Before a vowel dia- becomes di-; as, diactinic;
   dielectric, etc.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Deuto- \Deu"to-\or Deut- \Deut-\ (d[=u]t-)[Contr. from Gr.
   dey`teros second.] (Chem.)
   A prefix which formerly properly indicated the second in a
   regular series of compound in the series, and not to its
   composition, but which is now generally employed in the same
   sense as bi- or di-, although little used.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

dis- \dis-\ (?; 258)
   1. A prefix from the Latin, whence F. d['e]s, or sometimes
      d['e]-, dis-. The Latin dis-appears as di-before b, d,
      g, l, m, n, r, v, becomes dif-before f, and either dis-or
      di- before j. It is from the same root as bis twice, and
      duo, E. two. See Two, and cf. Bi-, Di-, Dia-. Dis-
      denotes separation, a parting from, as in distribute,
      disconnect; hence it often has the force of a privative
      and negative, as in disarm, disoblige, disagree. Also
      intensive, as in dissever.
      [1913 Webster]

   Note: Walker's rule of pronouncing this prefix is, that the s
         ought always to be pronounced like z, when the next
         syllable is accented and begins with "a flat mute [b,
         d, v, g, z], a liquid [l, m, n, r], or a vowel; as,
         disable, disease, disorder, disuse, disband, disdain,
         disgrace, disvalue, disjoin, dislike, dislodge, dismay,
         dismember, dismiss, dismount, disnatured, disrank,
         disrelish, disrobe." Dr. Webster's example in
         disapproving of Walker's rule and pronouncing dis-as
         diz in only one (disease) of the above words, is
         followed by recent ortho["e]pists. See Disable,
         Disgrace, and the other words, beginning with dis-,
         in this Dictionary.
         [1913 Webster]

   2. A prefix from Gr. di`s- twice. See Di-.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Disserve \Dis*serve"\, v. t. [imp. & p. p. Di?????; p. pr. &
   vb. n. Disserving.] [Pref. dis- + serve: cf. F. desservir.]
   To fail to serve; to do injury or mischief to; to damage; to
   hurt; to harm.
   [1913 Webster]

         Have neither served nor disserved the interests of any
         party.                                   --Jer. Taylor.
   [1913 Webster]

V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

DI
       Destination Index [register] (CPU, Intel, assembler)