(2) Had features of modern computer: punch card input, memory unit,
automatic printout, sequential program control, and 20-place accuracy.
(3) Wrote the Countess of Lovelace, "We may say most aptly that the
Analytical Engine weaves algebraic patterns just as the Jacquard loom weaves flowers
and leaves."
(4)
Designed, but never completed.
1-25. ELECTROMECHANICAL PHASE
a. It took 10 years to tabulate results of the 1880 census by hand. The
inadequacy of manual data collection and manipulation triggered the creation of
Hollerith's vertical sorter or census machine in 1890.
b. Hollerith's punch card-controlled machine automated the 1890 census.
(1) Hollerith used punch cards as a medium for data processing, whereas
Jacquard's loom had used punch cards to control a process (weaving).
(2) Automatic reading of information punched into card without human
intermediation; this reduced reading errors and increased workflow.
(3) Accessible memory store of almost unlimited capacity provided by
stacks of punch cards.
(4) The 1890 census was completed in only 3 years with the use of
Hollerith's vertical sorter or census machine.
c. Features of punch card equipment:
(1) Electromechanical machine: electric power provided mechanical motion,
that is, to turn the wheels of an adding machine.
(2)
Automatic reading: cards fed into a read-in station, results fed out on
punch cards.
(3)
Sorted, calculated, and summarized (individual steps of data
processing).
(4)
Drawbacks of punch card equipment:
(a) Manual intervention between processing stages, that is, people
handling trays of cards between each step. Separate machines to be fed, started, and
stopped.
MD0057
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