3 Types of Computers: Main Frame Microcomputerb) Largest b) Smallestc) Most Expensive c) Least Expensived) Stores the Most d) Stores Least Data Amount of Data Minicomputer 2nd Largest 2nd Most Expensive 2nd in Storing Data
Electrical Signals: Digital– Uses On or Off electrical signals. Analog – Uses a smooth continuous change in the electrical signal.
4 Parts of the Computer: Input – Enters data into the computer Output – Returns processed data Memory – Stores data Central Processing Unit (CPU) – The brain or the heart of the computer
Memory: Random Access Memory (RAM)2) Memory that we use when we are using the computer3) Can be changed4) Temporary Read Only Memory (ROM)6) Memory that the computer uses7) Can Not be changed8) Permanent
Central Processing Unit: Made up of the following two units: Control Unit – directs the flow of the program or data. Arithmetic Logic Unit (ALU) – all math and comparing is done here.
4 Parts of the Computer: MEMORY CPU INPUT CONTROL OUTPUT ALU
Inside the Computer: Computer Chip – thin wafer of silicon that is an 1/8th of an inch square. Integrated Circuit Chips (ICC) – integrated electrical circuits on the tiny computer chips.
Large Scale Integration (LSI) Process of making a computer chip: A design is made. The design is photographed and reduced to chip size. Photograph is “baked” on the silicon. The chip is magnetized. The chip is tested and placed in protective casing.
Computer Definitions: Bit (binary digit) – tiny electrical signal. If the signal is On = 1 and if the signal is Off = 0. Byte – Pattern of 8 electrical signals or 8 bits. Everything on the keyboard has its own pattern. Nybble – ½ a byte. Memory Size:e) 1 Kilobyte (K) – 1024 bytesf) 1 Megabyte (meg) – 1024 Kilobytesg) 1 Gigabyte (gig)–1024 megabytesh) 1 Terabyte (TB)–1024 gigabytes1 Gigabyte = approx 500,000 letter-size pages of text information
More Definitions: Computer Hardware – Any part of the computer (monitor, disk drive, speakers, printer…). Computer Software – Programs used on the computer (Microsoft Word, Power Point, Sim City, LOGO…..). Binary Code – Base 2 number system made up of 1’s and 0’s. ASCII Code – Each character on the computer has it’s own code number. (See the chart on the next slide). Don’t write this in your notes!