DEFINITION What is a Computer? com·put·er Pronunciation key (km-pytr) n. A device that computes, especially a programmable electronic machine that performs high-speed mathematical or logical operations or that assembles, stores, correlates, or otherwise processes information. One who computes. (American Heritage Dictionary, 4 th ed. Pub. 2000)
Binary Numbers 1 of 3 Computers speak binary. Binary language consists of combinations of 1's and 0's that represent characters of other languages (in our case the English language). Dont make the mistake of thinking that little 1's and 0's are running around inside of the computer. We humans prefer to think of 1's and 0's because its easier than visualizing positive and negative current flows or open and closed circuits which is what actually happens inside computers. A combination of eight bits represents one character in our language. One character in our language (eight bits) is referred to as a byte. (For example: 01000001 is a byte that represents an uppercase A; each 1 or 0 is a bit.)
Binary Numbers 2 of 3 Kilobytes, Megabytes, and Gigabytes If you understand that a byte is one character in our language, youve got it made because: 1000 bytes = 1 kilobyte (1,000 characters = 1 kilobyte) 1,000,000 bytes = 1 megabyte (1,000,000 characters = 1 megabyte) 1,000,000,000 bytes = 1 gigabyte (1,000,000,000 characters = 1 gigabyte)
Binary Numbers 3 of 3 Disk Capacity Its important to know how large your files are because eventually you wont have enough space on your disk to hold more files. Knowing the total capacity of your disk, how much space is left on your disk, and how large the file is, you can make accurate decisions as to whether to save the file to the current disk, or save the file to a different diskette with more disk capacity. Keep in mind that a low density floppy diskette holds 720 kilobytes of data, and a high density floppy diskette holds 1.44 megabytes of data. Put in easier to understand terms, a low density disk can hold approximately 300 typed pages and a high density can hold approximately 600 typed pages. Zip disks have 100 megabytes of disk capacity (about $10.00 each) or 250 megabytes of disk capacity (about $15.00 each). CD-ROMS have 650 megabytes of capacity (about $1.00 each) or 700 megabytes of capacity (about $1.50 each). Super Disks have 120 megabytes of disk capacity (about $12.00 each). Hard drives (disk drives inside of the computer) might hold anywhere from 30 megabytes (old computers) to 80 gigabytes (new computers) of data. Most computers today are sold with anywhere from a 5 gigabyte (portable/laptop computers) to a 120 gigabyte (desktop computers) disk capacity.
THIS IS A FEW OF THE DIFFERENT TYPES of COMPUTERS Desk top Lap Top Hand Held computer Computer computer
DEFINITION Hardware Vs. Software If you can touch it, its hardware
SYSTEM COMPONENTS CPU/PROCESSOR The CPU refers to the microprocessor chip. Sometimes the Tower is called the CPU. Its speed is measured in Megahertz (MHZ) (Millions of cycles per second) or Gigahertz (GHZ) Billions of cycles per second. (A cycle is the time required for the CPU to execute an instruction step).
SYSTEM COMPONENTS Ram – Random Access Memory Ram is the memory used by the computer to run programs. The amount of Ram available will determine how fast a program will run and how many windows can be open at one time. Ram memory is considered Volatile because it disappears when the power is turned off.
SYSTEM COMPONENTS Hard Drive The Hard Drive is the computers main, long term storage. It is referred to as non-volatile storage, because it does not disappear when the power is turned off. The size of the Hard Drive is measured in Gigabytes. (Billions of Bytes).
RAM VERSUS HARD DRIVE If we use the analogy of a desk: Then the work we are doing on the desk top would be using the RAM and the work we store in the file drawers would be on the HARD DRIVE.
SYSTEM COMPONENTS Mother Board (This is where most of the electronics is located).
POINTERS (CURSORS) I-beam cursor (which follows the roll of the mouse) Insertion point cursor F letcher (Which flashes on and off, and is positioned using the I-beam cursor and a click of the mouse button)
BREAK POINT Lets get some hands on experience Find the Windows key. –B–Bottom row second key from the left side. –P–Press once, (this is the same as left clicking on the start button). –B–Bring the cursor arrow over the All Programs Arrow head. –N–Notice how the program files are displayed.