EECS 1520 Lecture Notes - Lecture 10: Parc (Company), Darpa, Wilhelm Schickard

• School: York University
• Department: Electrical Engineering and Computer Science
• Course: EECS 1520
• Professor: Avi Cohen

Document Summary

Numbers can be added or subtracted by moving beads/knots. Earliest known inventor of a mechanical calculating device. First to implement mechanical calculating device, designed independently of schickard. Able to add and subtract by turning dials to change values. Jacquard loom - punch cards, used to code computer programs later. Used vacuum tubes to control flow of electrical signals. Known for commercializing early computing machines, mainframe computers and modern servers. Also developed methods for process information to improve computing performance. Only operate on a fixed amount of data at a time. Amount and type of data must be known ahead of time. Computers cannot work well with analog information. Analog signals continually fluctuate in voltage up and down. Digital signals have only 1 high or 0 low. All electronic signals degrade as they move down a line, only digital; can regain original shape. Voltage of the signal fluctuates due to environmental effects. Sign x mantissa x 10 ^ exponent.