/-3-FS ■& 6 '^/ff 25$ Selecting a home computer Computers are becoming a part of What do I want the computer delete a character, etc. Most keyboards our daily lives. Using a computer is to do for me? produce upper- and lowercase letters, somewhat like driving a car. We don't This should be the first question you but some may not. Some software need to know how a car's engine works ask as you consider purchasing a home requires lowercase letters. to be able to drive it. Similarly, we can computer. Make a list of things for Groups of instructions may be use computers without knowing every- which you expect to use the computer. stored in the microcomputer by using thing about the "inside workings." The list will be helpful when you its internal memory. There are two Shopping for a home computer can compare various computer systems. In types of internalDATE. memory. Read only seem like trying to understand a general, evaluate the capabilities of memory, ROM, consists of perma- foreign language. If you understand computers, rather than specific brands. nently installed instructions to the the basics of home computers and A computer can be a multipurpose computer. ROM may contain a know what questions to ask, you will tool. It can perform bookkeeping programmingOF language such as BASIC, have more confidence in shopping for functions, keep inventories, write as well as the procedures to be followed and purchasing a home computer. letters, play games, and teach—as well when the computer is turned on. The More information can lead to better as turn lights and appliances on and information in ROM is not lost when decisionmaking and, thus, to satisfac- off. Each function will require differ- the computer is turned off. tion. What you purchase will depend ent operating capabilities (hardware Random access memory, RAM, is a on what you expect a computer to do and software). OUT temporary storage area for your use. and how much you can spend. To answer the question of what to Any information contained in RAM is Consider your own requirements use a computer for, a basic knowledge lost when the computer is turned off. carefully. A computer's features may of hardware and softwareIS is necessary. RAM is measured in kilobytes (K); one appear neither obvious nor important Hardware refers to the physical compo- K is made up of 1,024 bytes. to you as a prospective buyer, yet an nents of a computer system, such as the One byte represents one character. inappropriate machine could present keyboard, CPU, or monitor. Thus, a computer with 64 K of RAM unexpected limitations after the sale. Software is a set of instructions can store internally more than 64,000 The memory space might not be (usually on a disk or tape) that characters. The amount of RAM you sufficiently expandable; the keyboard performs functions as specified by the will need in your home computer or the display might be inadequate; the user. We will examineinformation: each of these in system depends on the operating software you want might not be more detail. system and software you will use. available for that computer. Some programs require 32 K of RAM; A wealth of information about others, as much as 256 K RAM. microcomputers is now readily avail- What is hardware? Since information in RAM is lost able. Trade magazines and books The basic unit of a home computer is every time the computer is turned off, feature descriptions of typical home a CPU—central processing unit. CPU's mass storage devices are necessary to computers and tips on how to buy and vary according to the amount of data store this information and load it back use them effectively. Computer user currentthey can process at one time. A 16-bit into RAM when necessary. groups, adult education and commu- CPU can process information inter- Storage devices use a magnetic nity college courses, andPUBLICATION acquaintances nally faster than an 8-bit CPU can, medium to record information, and who own computers are excellent although speed is not a very important several types are available. A hard disk resources. consideration for most home uses. drive accesses data the fastest, has the This publication will help you The CPU carries out commands largest amount of storage, and is the choose a home computermost by presenting received from the user through the most expensive. information about computer hardware keyboard. Some keyboards have sev- Floppy disk drives can store from and software,THIS and suggesting questions eral additional special function keys to 200 K to 400 K of information on each to ask yourself and your vendor before perform specific tasks. These function diskette. They're slower than hard disk you buy. For keys may erase the computer's display, drives but faster than cassettes. A http://extension.oregonstate.edu/catalog Extension Circular 1217 / January 1985 OREGON STATG UNIVeRSITY GXTGNSION S€RVIC6 system with two floppy disk drives is A modem is a device that allows Table 1.—Home computer software types preferred to a single drive system your computer to communicate with and uses because it can hold a program in one other computers by transforming your drive and data in the other. This computer's electrical pulses into audi- Software type Example uses reduces the number of times you'll ble tones for transmission over phone Business uses Accounting, payroll, rec- have to switch disks in and out of the lines. Modems vary according to the cord keeping, inventory drives. speed which they transfer data, meas- control, word processing A third method of storing data is ured as a baud rate. A 300-baud Education Tutorials, drills, exercises, with a cassette tape. Cassette tapes are modem transmits about 30 characters logic slower and hold fewer data than floppy per second; a 1,200-baud modem, Games Entertainment, education disks. They are the least expensive about 120. If you plan to do much Utility Operating systems, com- means of storing small programs and communicating with your computer, a munications, file handling data. Many home computer users start 1,200-baud modem will reduce your with a cassette system and then change long-distance phone charges. to a floppy disk drive as they use the computer more. What is software? do in the future. Some systems allow Characters generated by the CPU or Software provides instructions to a you to start with the basics and provide input through the keyboard are dis- computer and is the link between you "add on"DATE. or expansion capabilities to played on monitors or television sets. and your computer. The hardware we meet future needs. Less expensive Monitors are similar to television sets, just described is useless without good machines are suitable as starter but without tuners and with higher software. In the long run, your computers. There is no "best system" resolution to enable them to form software investment may exceed your for everyone. characters and graphic displays more OF hardware investment. You will need to budget for software precisely. You should shop for software before in addition to the cost of the basic Monitors may display more charac- you decide on hardware. This will give ters across the screen than a TV, hardware. It can be expensive. Word you some guidelines on what hardware processor programs can cost as much showing you more information. TV's you'll need and also on the brands of as $500—data base management pro- are often in color, which improves the hardware with which theOUT software is grams up to $700. Bargains are display of graphic images. compatible. Software is designed for available to the careful shopper. If you decide to use your TV as a specific brands of hardware. Be sure Some computers come equipped computer display, remember that that the hardwareIS and software you computer use and television viewing with "bundled" software when you purchase are compatible. buy a computer system. User groups will compete with each other. A special There are many types of software on adapter may be required to use your and magazines can be a source of the market, depending on your needs. inexpensive programs that perform TV with your computer. Table 1 lists some of the general types The information shown on a moni- many common functions. Investigate (there are many other types and uses of all available resources before you buy. tor can be printed out on a printer, software). Prices and capabilities vary Anticipate additional expenses that providing you with a permanent copy widely. information: accompany a home computer purchase: (or hard copy) of the output. There are Evaluate the software you are several types of printers available, but interested in as thoroughly as possible. • You'll need blank storage disks or the two most popular are letter-quality Examine the documentation that cassette tapes and a small TV set or and dot-matrix. accompanies the program, to see if it is video monitor. The letter-quality printer usually easy to understand. Try running the • A desk, chair, and lamp are also part costs more and is slower, but it program if possible (it is usually of the typical home computer produces printing almost identical to a possible and should be highly recom- workspace. typewriter. If you plan to do a lot ofcurrent mended). A number of computer • Budget for a magazine subscription, word processing thatPUBLICATION requires high periodicals are available that provide a few books, and a class or two to quality output, the letter-quality printer excellent reviews of software (see the help you get started.