COMPUTING DEVICE I (PRE COMPUTER AGE TO 19TH CENTURY) WEEK THREE COMPUTING DEVICE I (PRE COMPUTER AGE TO 19TH CENTURY)

CONTRIBUTION TO PRESENT DAY COMPUTER NAME OF DEVICE ITS FEATURES BASIC COMPONENT TYPE CONTRIBUTION TO PRESENT DAY COMPUTER MAIN USES Abacus Beads, strings, could add and subtract on a small scale Mechanical Digital counting For small scale counting and addition Napier’s bones Iron rod sliding against each other in a box could multiply and divide on small scale. Mechanical uses the principle of logarithm Analog As calculating machine in small scale businesses and in pre-nursery schools. Slide rule Sliding rulers against one another could multiply and divide on small scale. Used as calculating machine now obsolete Pascal machine ‘Ratchet carry’ mechanism could add large numbers Automation Used as business adding machine now obsolete Leibnitz machine Rotating gear system, could multiply and divide large numbers Used as multiplier to improve on Pascal’s adding machine Jacquard Loom weaving It tugged multicoloured threads into patterns by means of array of rods, had holes punched in card warps. Programmed for different patterns using punched cards. A mechanical textile weaving loom Binary representation by hole recognition, card-reading technology programming instruction. Local weaving devices

Babbage’s analytical engine Has the mill, the store, the reader and printer which are prototype of the present processor, memory, input and output devices respectively in present day computer Electro-mechanical I/O devices, punched card, memory, processor. Regarded as the first fully programmable computer. Hollerith census machine Could compute large numbers, tabulate and record result Punched card automation Used for computing census data and tabulating the result used as one of the early business machine as commercial calculator. Burroughs machine Similar to Hollerith’s but could add numbers, record and list result Listing/sorting concept automation Used in business as commercial calculator and listing machine

ASSIGNMENT List four(4) 19th century computing devices State two (2) features of Babbage’s and Hollerith machines State two (2) common features of slide rule and Napier’s bones