Understanding the Different Types of Computers
When we look at Computer Type, the fun (or confusion) begins. Computers are classified according to their storage and computing capacity, the number of users that can be supported, the variety of input and output options, and their physical size. There are three main types of computers:

Mainframes are used by many school districts, state education agencies, and universities because they support so many users and have the storage and computing capacity needed for large data sets.

Minicomputers, such as the Digital Equipment Corporation VAX and the IBM AS/400, are between mainframes and microcomputers in both size and capacity.

Microcomputers, a.k.a. Personal Computers or PCs, are today's computers of choice because their speed, power, and capacity have increased, yet the cost of processing power is much lower than for mainframes. They are small (desktop size) and use a microprocessor chip (the brains of the unit) to run the computer. PCs are generally used by only one person at a time, but can be networked to provide communication with other PCs, mainframes and minicomputers. PCs may also be described by physical size, such as desktop, laptop, and notebook. Both Macintosh and IBM-compatible (e.g., Windows™, Linux operating systems, etc.) computers fit into this category. Making things more complicated, however, is the server, which oftentimes is little more than a PC equipped with large amounts of storage for "serving" software on demand to other networked computers.

While the process of putting together a technology system is basically the same no matter what type of computer is desired, our focus will be on microcomputer (PC) systems.

Becoming Familiar With Microcomputer (PC) Manufacturers and Models

Understanding Computer Characteristics

Another key parameter affecting performance is the amount of Random Access Memory or RAM (space in the computer on which information is temporarily stored while the computer is on). RAM is measured in bytes, where a byte is one number, letter or symbol. One megabyte (MB) of memory is equal to 1,048,576 characters, which is approximately equal in size to a novel of average length. Software applications often drive the need for RAM; for example, a graphical arts package might not even work on a machine with less than 128 MB of RAM. Thus, when purchasing a computer it is important to anticipate the growing RAM needs of the software you expect to use.

Inside the microcomputer is a hard drive (a.k.a., hard disk drive), which is a device used to more permanently store information, such as programs and data. Storage on the hard drive is also measured in bytes. Today's newer personal computers usually have more than 4 gigabytes (i.e., 4,000 megabytes).

The next significant attribute of the hardware is determining which Operating System (OS) it runs on. Operating system software contains the electronic instructions that control the computer and run the programs. Most are specific to a type of computer.

Some commonly used operating systems include:

Windows (95, 98, 2000 or NT)
Macintosh OS
UNIX (of many kinds)
OS/2
Linux
MVS
VMS

The platform that a computer runs on is the hardware and operating system software together. Software applications will not run if the operating system they require is not installed on the computer. Fortunately, some software will run on multi-platforms, which means that it can run, for example, on computers using either Windows or a Macintosh operating system.

Identifying Peripherals
A peripheral is any component that attaches to your system unit such as a monitor, keyboard, mouse, modem, CD-ROM, DVD, printer, scanner, microphone, and speakers. Below is a list of definitions that you may need to refer back to from time to time.

Monitor. A monitor is the computer display screen. Monitors, like televisions, contain Cathode Ray Tubes (CRTs). Monitors may display in black and white (old ones) or color (newer models). The clarity of the images on-screen is referred to as their resolution. When purchasing a monitor, a key consideration should be the number of colors it is capable of displaying; the more colors displayed, the more realistic is the image on the screen. A Video Graphics Array (VGA) monitor displays 16 colors, which is the minimum standard. Super Video Graphics (SVGA) monitors display many more colors.

Keyboard. On a computer, the keyboard is used to type information and instructions into the computer. Most have number pads and function keys that make the computer software easier to use.

Mouse. The mouse is a hand-held pointing device (used on top of a desk) that gives directions to the computer and moves information around on a monitor screen.

Printer. A printer translates signals from the computer into words and images on paper in black and white or color. Printer types include dot matrix, ink jet, laser, impact, fax, and pen and ink devices.

Cables. Cables used to be collections of wires twined together to connect peripherals to the system unit. Other cables now being used include "fiber-optic" cables, which move larger amounts of information over the network at a faster speed.

Modem (a short form of "modulator / demodulator"). The modem connects a computer to a telephone line for communication with another remote computer or information network. Modems may be internal or external to the computer case. Modems send and receive information at different speeds. Faster modems accomplish more work per unit time (e.g., per second or minute). Before purchasing a high speed modem, however, be sure to verify that the phone lines can handle the speed advertised on the modem box! There are also cable television modems and DSL modems available in some areas that allow even greater transfer speeds. But, when examining the needs assessment or technology plan, it will probably become clear that for a school, it is more efficient to set up a network rather than rely solely upon modems.

Scanner. This is an input device that takes in an optical image and digitises it into an electronic image represented as binary data. Scanners are used to create computerised versions of a photo or illustration.

Switch. In the olden days (i.e., two years ago) a little box called a "hub" was the point at which computers were connected to the local area network. Today, we use smart hubs, called "switches."

Router. As the name implies, this small computer sits between the outside world and the computers in a local area network and distributes ("routes") information coming in and going out. For example, when a message comes from the Internet into a school, the router sends the information to the computer that is supposed to receive it. The router is like the police officer giving directions at an intersection, sending data to the computer that requests the information.

Considering Furniture
Often when an equipment budget is being established for a new technology system, the element that may be forgotten is the need for appropriate furniture to accommodate it. This is important for a variety of reasons, the most important being security, safety, and comfort. Furniture should be ergonomic (i.e., designed for utility and comfort) and receptive to security (e.g., wires, bolts, etc.).

Developing an Inventory

In order to make the best possible use of existing hardware, your technology inventory should contain the following information for each computer system:

• Computer type (e.g., desktop, laptop, mainframe).
• Computer manufacturer, model, and characteristics (e.g., type of CPU, amount of RAM, and size of hard disk).
• Peripherals and capabilities they support.
• Intended uses (e.g., classroom instruction, correspondence, record keeping, accounting, graphics).
• Networking capability.
• Location - building/room.

You should also document information about furniture allocated specifically for computer systems.