CRASH COURSE COMPUTER SCIENCE*

*I would name it CRASH COURSE COMPUTER ENGINEERING instead

Episode #2 – Electronic Computing

PART A – ELECTRO-MECHANICAL COMPUTING (0:00-3:35)

1. One of the largest electro-mechanical computers ever built was the ________________ completed in 1944 by IBM for the Allies in World War II. It contained _______________ components, _______________ connections and _________________ miles (which is about ________________ kilometers) of wire.

2. At the time, the brains for these large electro-mechanical machines were _____________ which are electrically-controlled mechanical switches. These devices consist of an electro-magnet that physically moves a metallic switch to close/open a circuit.

3. While relays at the time could switch up to 50 times in a minutes, this was not ______________ enough to be useful to solve large problems in an efficient amount of time.

4. With such relays, the Harvard Mark I could do ______ additions per second and ______ subtractions per second. It took ______ seconds for a multiplication and ______ seconds for division. More complex operations could take over a minute.

5. Another significant issue with the large electro-mechanical machines was _________________ that took place inside the relays. Relays would fail regularly and that is an issue when trying to run multi-day calculations.

6. In 1947, operators working on the Harvard Mark II removed a dead ___________ from a malfunctioning relay. From that point on, issues that occurred in a computer were known as _______________.

fast 765,000 6 15 bug

wear and tear 800 3,000,000 relays 3

moth 500 Harvard Mark I 3

PART B – VACUUM-TUBE-BASED ELECTRONIC COMPUTING (3:35-7:15)

1. In 1904, ___________________ invented a new electrical component called a thermionic valve, also known as a _______________. The initial version of this device only permitted the one-way flow of electrons and is known as a _____________.

2. In 1906, inventor ______________ created the _______________ which was a modification of the original vacuum tube to allow it to act like a switch. It would work like a relay but without moving parts. This allowed it to switch thousands of times per second. These devices would be the basis of radio, long distance telephone and many other electronic devices for nearly 50 years!

3. By the 1940s, the _____________ and _____________ of vacuum tubes improved to the point that they could be used in computers. This lead to the shift from electro-mechanical computers to electronic computers.

4. The first large-scale vacuum tubes computer was the _______________ and was built Bletchley Park (UK) by ______________ in 1943. It was used to decrypt enemy communications during World War 2.

5. The above description may sound familiar. Two years prior, also at Bletchley Park (UK), __________________, often called the father of computer science, created an electro-mechanical device called The Bombe to also aid in breaking enemy Enigma codes.

6. The first version of Colossus Mark I contained ___________ vacuum tubes. This device is regarded as the first ______________, ______________ computer. Programming was done by plugging hundreds of wires into plugboards. This computer required to be configured to complete a specific task.

7. In 1946, _________________ was built at the University of Pennsylvania. This was the first _____________ ______________ _______________ computer. It could perform ____________ ten-digit additions or subtractions per second – many many times faster than any other machine at the time.
   
   
8. Over ENIAC’s _____________ year life span, it is estimated to have done more arithmetic than the entire human race up to that point!

cost general purpose John Ambrose Fleming programmable vacuum tube diode

Lee de Forest 10 triode vacuum tube Tommy Flowers 1600 electronic

reliability Colossus Mark 1 Alan Turing programmable electronic 5000

PART C – TRANSISTOR-POWERED ELECTRONIC COMPUTING

1. By the 1950s, _____________ computing was reaching its limits due in part because of the vacuum tube’s tendency to fail and halt computer use.

2. In 1947, Bell Laboratory scientists _____________, ____________ and _______________ invented a new electronic device called the ______________. This device can act like a switch and even the very first ones could switch states ten thousand times per second. Unlike fragile vacuum tube, these devices are _____________.

3. The era of the transistor quickly led to dramatically _____________ and _____________ computers.

4. For example, the ___________ was released in 1957 and was the first fully transistor-powered commercially available computer. It contained ____________ transistors and could perform ______________ additions or roughly _____ multiplications or divisions every second.

Walter Brattain 4500 Transistor IBM 608

Smaller 3000 John Bardeen William Shockley

vacuum-tube-based solid state components cheaper 80

PART D – MODERN COMPUTING (9:11-End)

1. Today, modern computers use transistors that are _____________ nanometers is size. For comparison, a page is about 100 000 nanometers thick. So 2000 transistors side by side would be the same length as the thickness of a page! These transistors can also switch states millions of times per second and can be reliable for decades.

2. The Santa Clara Valley, the location between San Francisco and San Jose (California), is where much of this transistor and semiconductor development occurred. It is now known as ____________ named after the most used semiconductor.

3. __________, the largest chip maker in the world and many other companies were created in Silicon Valley.

Silicon Valley

50

Intel