Data General Corporation, 258
Data processing. See Programmed Data Processor
Data tabulation, for 1880 Census, 70–6
Decimal machine. See ENIAC; UNIVAC
Decimal point, invention of, 12
Decimal vs. binary systems, 34
Decoder, electronic, 146
Defense Calculator (IBM 701), 192–3
Defense network, computerized. See SAGE computer
De Forest, Lee, 225
Delamain, Richard, 11
Delay lines, 150–1
Deltamax, and computer memory, 201–2
Difference Engine, 36, 41–4, 58–9

construction of, 47–57
plans for, 43
size and description of, 54–55
sketch of, 48
uses of, 57

Differential analyzer, 87, 113, 122

building of, 87–88
initial idea for, 86
universities and, 107–8

Differential equations, 83
Digital electronic calculators

development of, 113–8
special purpose (see Atanasoff-Berry Computer)

Digital Equipment Corporation, 255, 257–59, 265, 266–68

development of personal computer and, 267–68
founder of, 202
PDP-1, 257
PDP-8, 257–58, 267
VAX- 11/780, 258

Digital vs. analog devices, 13, 15
Distributed processing, 258
Dodd, Stephen, 201
Dudley Observatory, 57
Dummer, G. W. A., 230–32
Durfee, Benjamin M., 104