OFF ON Gone Computing Cycle 8 Step 3: Output Information comes out as a result of processing. *Computer -an electronic device used for input, processing, storage and output. Hardware - physical parts of the computer. Software-programs or instructions that tell the computer what to do. Step 2: Processing Computer acts on the data inputs. 3+5= CPU -central processing unit sits on a ... Microprocessor-a single silicon chip made up of the 2 parts listed below: 5 3 Printer-provides hard copy output (permanent output) Monitor- soft copy output (temporary output) ALU-Does the math(“A” = arithmetic) Control Unit = Works with input & output devices. Step 1: Input - Ways data enters the computer for processing. 3.1 million instructions Memory Computer Understands: ROM or RAM? Memory is like a chalkboard... Types of Input Devices: Keyboard Mouse Joystick Modem (Phone lines) Digital Camera Microphone Scanner Disk CD Touch Screen ROM=Read Only Memory - permanent instructions in computer. Byte= 8 bits - or 1 character A=0 1 0 0 0 0 0 1 RAM -Random Access Memory- temporarily stores data inside a computer. Kilobyte (K)= 1000 bytes = 1 page of double spaced text How much memory you have determines how many __PROGRAMS__ you can run at once and how fast they will run. Data stored in memory __DISAPPEARS__when you turn off the computer. Megabyte (MB)= 1,000,000 = 1 million bytes or one novel Gigabyte (GB)= 1,000,000,000 = 1 billion bytes or 1,000 novels
Magnetic Disk- storage for files-can be hard disk or floppy disk. Allows RANDOM access to data. Disk drive - A computer unit that “writes” & “reads” data on a magnetic disk. Has “heads” to read data. Usually, A & B drives read diskettes, and the C drive is the hard disk. Hard Disk - Storage INSIDE the computer. Usually called the C: drive. Holds more than floppy disk. Floppy Disks- flat circular objects on which computer data is stored. You can carry them with you. Magnetic Tape- Another way to store data outside the computer. Usually slower than disk because tape is SEQUENTIAL. Tape Drive - used to read & write (store) data on magnetic tapes. Random Access -Can select the information, without following any specific order. Easy to find. (Example: using a CD ROM - can find any song you want instantly; Computer example: diskette or hard drive with tracks or CD ROM) Sequential access- means “one after the other”. You must go through all of the information, in order, until you get to what you need. (Example: listening to a cassette tape. To find the song, you must go through the other songs first - Computer example: computer tape drive, slower) Storage (permanent) Computers store information in _FILES____. Information stored on disk is _STILL THERE________ when the power is turned off. Backup Copy- A copy of a computer information on tape or disk to be used if the original fails or is damaged. Examples of things you might want to back up: Backup important files Backup your hard drive Make a backup copy of a floppy disk Don’t Forget to Back Up!