1-22. MACHINE-ASSISTED MANUAL PHASE
a. By the 17th century, overworked clerks could not keep up with the need for
fast, accurate record-keeping and computing in such areas as: astronomy, engineering,
census-taking, and tax collection.
b. Various machines to assist in manual computation were designed and/or
developed in this period.
(1) Digital calculating clock--Shickard, 1623. (His adding machine preceded
Pascal's, but his work was lost until 1957.)
(2) Adding machine--Pascal, 1642. Commonly credited as the first,
because Schickard's work was lost. Could add and subtract by carrying over. Other
operations performed through a cumbersome process of repetitive additions. System of
interlocking wheels central to most adding machines for the next 300 years.
(3) Von Leibniz's calculating machine, 1673. A multiplication and division
device was attached to Pascal's basic machine so that these operations were
accomplished through a process of successive adding.
Colmar's calculator, 1820. The first commercially successful mechanical
Bollee's calculator. 1887. Eliminated the need for repeated additions.
1-23. PUNCH CARD DEVELOPMENT
a. Jacquard's punch card-controlled loom, 1801.
B. First application of punch cards to control a process: weaving patterns for
1-24. AUTOMATIC MECHANICAL COMPUTERS, 19TH CENTURY
Charles Babbage--100 Years Ahead of His Time. Conceived of modern
programmable computer with printout and memory before the necessary technology
a. Difference engine, 1823. Automatic mechanical calculating machine,
designed to prepare astronomer's math tables; never completed.
b. Analytical engine, 1833.
General-purpose, programmable, automatic mechanical digital