Inventors: | Howard Aiken, C. D. Lake, F. E. Hamilton, B. M. Durfee.
|
Place: | Endicott, New York; moved to Cruft Laboratory, Harvard University;
then to the Harvard Computation Laboratory.
|
Dates: | Proposed 1937; construction begun 1939; completed January, 1943;
placed in operation spring, 1944; dedicated August 7, 1944. In use until 1959.
|
Cost: | $300,000-$500,000, exclusive of R & D.
|
Technology: | Electromechanical, 3,000 decimal storage wheels. 1,400 rotary
dial switches, 500 miles of wire.
|
Size: | 51' x 8' x 2'; 19 panels; weight 5 tons.
|
Number
Registers: Decimal system, 23 digits plus sign (0 = + , 9 = - );
provision for half- or double-precision arithmetic; subtraction by 9's
complements; parallel transfer of all numbers.
| Memory: | 72 accumulators; 60 constant registers (set by 10-position
switches); 3 value-tape readers.
| Processor: | Multiplier and divider, multiplication by table look-up; all
addition and subtraction done in accumulators; special circuits for log and
antilog (to base 10), sine, and interpolation of functions.
| Programming: | 1 sequence tape reader, using two-address code: out-field,
in-field, miscellaneous, other sequencing by plugboard; 1 "choice register"
and 1 "check register," allowing internal logical control.
| Speed: | Cycle time: 300msec. (one rotation of shaft); multiplication time
approx. 6
sec.
| Input: | 3 value-tape feeds, 2 card feeds, plugboard, switches.
| Output: | 1 card punch, 1 tape punch, 2 automatic typewriters.
| |
How the Mark I actually solved problems may be considered separately from
what it was physically made of; the latter is the machine's "anatomy,"
while the former is its "physiology." Although the Mark I's components were similar to
those of commercial business equipment, it obviously worked in a different
way. In fact, its physiology was remarkably similar to other contemporary
computers, even if they had completely different physical anatomies.