[CrashCourse CS] #2 Early Computing

Start of 20th century(1900s).

• Special purpose computing machines like tabulating machines were a huge boon(요긴한 것) to government and businesses, aiding and replacing rote(암기) manual tasks.
• Increase in population, global trade, transit(수송), sophistication of engineering and science
• Explosion of complexity, bureaucracy(관료체제), and use of data drove a need for automation and computation.
• Cabinet sized computers grew into a room-sized behemoth(거대한 것) that were expensive and prone to errors.

Harvard Mark I

• Largest computer, completed in 1944 by IBM for the Allies during WW2
• Earliest use for this machine was running simulations for Manhattan Project.
• It was ran by machanical relays - electrically-controlled mechanical swithes.
• It uses control wire to open or close the metal arm, which connects or disconnects the circuit.

Relays(계전기)

• A relay has mess, and therefore can't move instantly between opened and closed states - not fast enough for complex calculations. Also wear and tear overtime.
• The huge, warm machine attracted bugs - bug inside a malfunctioning relay. The term computer bug was created.
• Good relay could flick back and forth 50 times/sec.

Vacuum tubes invented

• had no moving parts, replaced machanical relays.
• But fragile and could burn.
• A shift to electro-machanical to electronic computing.
• Switch 1000 times/sec.

Colossus Mk 1

• First large-scale use of vacuum tubes for computing, 1943, decrypted Nazi communications.
• First programmable computer, by plugging hundreds of wires into plugboards.

ENIAC - Electronic Numerical Integrator And Calculator, 1946, UPenn.

• General purpose, programmable, electronic computer.
• But many vacuum tubes caused common failure, and operational only for half a day at a time befroe breaking down.

Invention of transistor, 1947.

• Just like a relay and vacuum tube, it is a switch that can be opened or closed by applying electrical power via a control wire.
• Uses semiconductor.
• Switch 10,000 times/sec.
• Small, solid.
• IBM 608, 1957 - fully transistor powered computer.
• Computers were trasitioned to transistors.

Today's transistors are very small, fast, and run for long.
A lot of transistor and semiconductor development happened in the Santa Clara Valley (San Fr ~ San Hose).
Most common material used to create semiconductors is silicon - "Silicon Valley".

Thoughts

• Mechanical Calculator -> Relays -> Vacuum Tubes -> Transistor 의 발전 과정이 흥미로웠다. 어쨌든 근본은 스위치 여러개가 조합되어 컴퓨터가 만들어진다는 것이다.
• 컴퓨터의 역사는 100 년이 조금 넘었지만 발전은 매우 빠른 것 같다.
• 컴퓨터 버그라는 단어의 기원이 Relay 안에 들어간 벌레 때문이었다는게 정말 흥미로웠다!