Study Notes

The first computer was designed by the English mathematician Charles Babbage. Charles Babbage wanted to build a machine called “analytical engine” .He asked Ada who was the daughter of the famed English poet Load Byron to write software for his machine. Ada was the world’s first programmer. During the World War II, the computer industry grew very fast. Both American/British and Germany tried to make powerful computer that was used to decoded. They used Vacuum tubes or electromechanical relays. There were only machine language and even a plugboard which was wired with many electrical circuits. The operator put the plugboard in the computer and waiting for output. Later, plugboard was replaced by punched cards. The programmer wrote the code and then punch the card, go to the computer room and gave the cards to operator. The operator put the punched cards to computer, and choose the related compiled board, run the program, print the result to the programmer who was always waiting for a moment. In 1950s, with the introduction of transistors, computer became more reliable. These machines, now were called mainframes. The program had to wait for its former program was finished, while it caused a large of wasted time. In order to increase rate, the resolution was batch system. There were three computers, one IBM 9402 and two IBM 7401. IBM 7401 was character-oriented. It reads the punched cards provided by programmer, and write to a Tape. Then when written-in jobs were full, unload the tape and mount it at IBM 9402 which was word-oriented for scientific calculating, 9402 would execute the code and write the output to a new tape. Unload the new tape and mount it at another 7401, printed the result. Later, people wanted to take the advantage of both 7401 and 9402. IBM made the System/360 series computer that were very successful.The IBM 360 was the first major computer line to use ICs（Integrated Circuites).