CAS CS 101 Lecture 10: cs 101 midterm notes (lecture 1-10)

• School: Boston University
• Department: Computer Science
• Course: CAS CS 101
• Professor: donham

Document Summary

1st computers: math with hands, calculus latin for pebbles stonehenge- solstices, floods, seasons. passage of time is what its used for. 2,500 bce abacus 3,000bce mechanical devices to modern computers: Change metal punch cards to weave tapestries/patterns with elaborate, programmable patterns. Programmed by punch cards showed general layout of modern computers. Babbage never completed a functional machine b/ the design beyond tech of his day. Physical switch, which can be opened/closed via electrical current/voltage to a magnet. could store only 72 numbers, required 1/10 sec to add, 6 sec to multiply. Colossus+eniac: input using dials & knobs, paper tape. British govt built it based on alan turing"s designs. Nazi decoding used so top secret. didn"t influence others. Weighed 30 tons, consumed 140 kwatts von neumann stored program computer idea: memory, cpu, i/o. 0"s & 1"s corresponding to the settings of physical components. In 1950"s, assembly languages replaced 0"s & 1"s with mnemonic names e. g. , add instead of.