what is a computer
Computer: A computer is a box of electronics, but it’s more than that. Inside the computer is theCentral Processing Unit (CPU), which is a big, square chip. It uses commands to manipulate the information. That information is stored temporarily (thus called volatile media ) in Random Access Memory chips (RAM chips), which nowadays are called SIMMs. The CPU also draws information from the Read Only Memory (ROM) chips. It can draw further information from the nonvolatile media, such as disks, hard disks, PC Cards, or CD-ROM disks. The input device can be anything that converts motion or energy into a digital signal and sends it to the CPU. This can be a keyboard, a mouse, or a joystick. It can also be a button, motion sensors, a burglar alarm, or a radar dish. After the signal has been processed, it’s sent out. It can go to a non-volatile media, namely a disk, hard disk, or tape, where it’s stored. It can also go to your screen as pictures or text. It can be sent to the printer or through a cutter with a diamond-tipped drill to carve headstones. It can be sent through your speakers as sound. It can be sent through a modem to another computer. The computer can also move a robot arm, switch a railway track, lower the landing gear, or guide a surgical laser. A $4 pocket calculator has all of the main parts of a computer: a keypad (input device), a bit of ROM memory which holds the mathematical rules and a bit of RAM memory to hold the numbers, and a tiny CPU that performs the operations. The result is output to the digital screen as numbers. Even your electronic coffee maker or microwave has these parts: input, processing, output. When you prick your finger, the nerve cells covert the force into electrical impulses (input) and send them to the brain. The brain (or the CPU) figures out that this is probably due to the cactus in your hands. The brain then tells your hand muscle to back off (output). Another signal goes to your mouth (audio output) and you say mercy!The dinosaurs were so long that a nerve signal could take five seconds to reach from their tail to their head. Before computer games were invented, caveboys would sneak up on a dinosaur, kick their tails, and then run back into the caves. The dinosaur would say mercy! and then look around puzzled. So what’s a computer? It’s the mechanical processing of information in order to do something. Tiny electronic gates open and shut to move electrons around. This is why computer people call them machines.