Computer & Network Paramedics, Inc.

How a computer works

The brain of the computer is called the Central Processing Unit (CPU). It is located inside the main box on a printed electric circuit called a Motherboard; it is a 'micro-chip', a piece of ceramic-like material that has billions of microscopic electrical connections etched onto it. Any form of information (words, pictures, sounds, numbers) can be converted to electric signals that are 'input' to the chip. The electric connections on the chip allow these signals to be compared to one another and combined with one another according to a 'program' that 'processes' or manipulates the information into a new form, which becomes the 'output' electric signal from the chip. Everything else in a computer is designed to take human information and convert it to the input electric signals for the chip, or to take the chip's output signals and convert them back to a form that humans can recognize. These other components are called 'peripherals', or just input and output devices. 

 The parts of the computer

What you see when you look at a typical computer workstation is:

• a Monitor -- looks like and basically is a TV screen and controls
• a Keyboard -- like a typewriter but with many useful extra keys
• a Mouse -- a palm-size gadget that rolls on a ball and has buttons on it
• a Printer -- inkjet or laser-xerox miniature printing machine a microphone and speakers -- if you're lucky, not all machine have these
• a pair of stereo Speakers, for multimedia systems (also sometimes a Microphone to speak into)
• a miniature TV camera -- if you're very lucky; not yet common
• the BOX -- contains the CPU microchip and all the really important components

So then, what's in/on the BOX?

On the Front of the box:

• On/Off switch (sometimes on the side)
• Reset button -- only on some machines
• Floppy-disk Drive -- you put in a square disk that contains information
• CD-ROM drive -- you put in a digital CD platter that contains a lot of information
• Tape Drive -- optional, for storing information in case something goes wrong
• Other special drives -- old-fashioned big diskette drive, super-new storage drives
• On/off light, Hard Disk Operating light, miscellaneous lights and buttons

Inside the Box. What you see on the front is just the opening slot of the actual drives. A 'drive' is a storage device. In addition to the CPU chip and the input and output devices, computers need places to store information either temporarily or more permanently (for reuse later), the short-term storage is called RAM (random-access memory) and is expensive. For longterm storage various kinds of disks and platters and cassettes are used; these are basically like videotape, but much higher quality, or like CDs. The drives read the information off these storage media and pass it on to the CPU; some drives can also write new information onto the disk or platter/CD or cassette.

• The CPU and RAM memory chips on the 'motherboard'
• The HARD DRIVE -- the main longterm storage system for programs and info
• The Disk and CD-ROM drives -- the main part of them is inside the box
• The specialized 'Boards' -- these run the input and output devices
• The Modem -- one of the boards; connects to the telephone line
• Network Board -- another board, connects to the LAN (see below)
• Video Board -- connects to the monitor
• An electic power supply, battery, and a lot of connecting cables

Every input device and output device is connected first to a specialized Board that has its own microchip to convert signals and pass them on to the CPU (on the main or Mother Board).

On the back of the Box. This is where all the input/output peripherals are connected to the Box, and the Box is connected to the electric outlet, the telephone system (for a modem), and the local area computer network (LAN) cable system. There are a lot of confusing cables back here. Sometimes they come lose. The specialized Boards stick out the back slightly, just like the drives stick out the front slightly. The Boards have connector sockets called Ports where the keyboard, mouse, printer, monitor, etc. are supposed to be plugged in.

The Operating System

The operating system is the master program that runs the computer behind the scenes while you work. It translates your instructions into actions by the machine. It also heads off conflicts between one part of the machine and another, making them all take turns. The most common operating systems are Windows, MacOS, and Unix. DOS is an older system that is now a small part of Windows.

• Difficulty logging into secure websites like WebMail and WebCT
• Random advertisements that pop up on your computer
• Unusual slowness of your system
• Unusual instability in your system (computer crashes or locks-up more than usual)
• Odd behavior in Internet Explorer such as redirection to search sites that you've never seen, or your homepage has been switched to a weird page.
• Other web pages open without any action by  you.
• Pornographic or other images load randomly on your computer when running your browser