3. 1800s Industrial revolution Boolean logic Punch cards – these are mechanical devices https://www.yo utube.com/watc h?v=7E9G9QATI Gg https://www.yo utube.com/watc h?v=7E9G9QATI Gg

4. Babbage’s Analytic Engine “First Computer” Ada Lovelace – first programmer 1837 Transition from arithmetic to general computation Expandable memory Programming language Arithmetic unit 1K of memory Speed: 10Hz (mega is million)

5. The theory of computation continues to develop Church-Turing thesis. The thesis states that a mathematical method is effective if it could be set out as a list of instructions able to be followed by a human clerk with paper and pencil, for as long as necessary, and without ingenuity or insight. A Turing machine (1936) is a hypothetical device that manipulates symbols on a strip of tape according to a table of rules.

6. Hardware: Claude Shannon Shannon showed that electronic relays and switches can realize the expressions of Boolean logic Part of why computers do 01 Digital circuit design (1930s)

7. Alan Turing “Father of CS” WWII: Code breaking – Colossus, the first programmable digital computer – The Imitation Game Prosecuted for homosexuality under British law – Committed suicide in 1954 at 41

8. ENIAC Built at University of Pennsylvania, Mauchly and Eckert, between 1943-45 First electronic general-purpose computer. Combined high speed of electronics with the ability to be programmed for many complex problems. It could add or subtract 5000 times a second, a thousand times faster than any other machine. High speed memory was limited to 20 words (about 80 bytes). Weight was 30 tons, used 200 kilowatts of electric power and contained over 18,000 vacuum tubes, 1,500 relays, and hundreds of thousands of resistors, capacitors

9. The first actual computer bug was a moth. It was stuck in between the relays on the Harvard Mark II, and documented by Grace Hopper. 1947

10. Grace Hopper Was one of the first programmers of the Harvard Mark I computer (1944) Developed the first compiler (1952) for a computer programming language. She conceptualized the idea of machine-independent programming languages, which led to the development of COBOL, one of the first modern programming languages.

11. Transistors! Invented 1947, de rigeur in computers starting in ‘55 More reliable and miniaturizable, less power (thus less heat) than vacuum tubes Your computer has billions of transistors – Modern silicon commercial transistors may be smaller than 45 nanometers in size. Shockley invented transistor at Bell, but moved to Mountain View, developed the silicon transistor

13. Silicon Valley Stanford University Navy – Moffett Field 1940s and 1950s, Stanford, encouraged faculty and graduates to start their own companies. – Hewlett-Packard (1953) – SRI silicon-based integrated circuit, the microprocessor, the microcomputer SV employs about a quarter of a million information technology workers.