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/-3-FS ■& 6 '^/ff 25$ Selecting a home

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 without knowing every- which you expect to use the computer. stored in the 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 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 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. 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- 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 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. 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 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 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. . 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. is a good choice. It uses a printing list on page 3). • Set aside some money for last- wheel similar to the typing elements on electric that can be changed minute surprises such as a printer cable or surge protector. for various type styles.most How much do I want THISThe dot-matrix printer is faster and to spend for a computer? And be sure to budget enough time less expensive than the letter-quality This is probably the second most to become familiar with your computer printer, but it produces a lower quality important question to ask yourself. and to learn to use it effectively. of print. ForNew models print in two or The price of home computer systems Besides the availability of particular three modes, such as a low quality varies from about $600 to over $7,000. software, other factors may determine draft mode and a high quality letter Obviously, comparing costs and - which computer is best for you. These mode. It does thishttp://extension.oregonstate.edu/catalog by printing over the tem capabilities becomes very impor- include estimated data storage require- same line two or three times, so the tant. Look for a hardware system ments, planned future enhancements higher quality mode will be slower. within your price range. Balance your (such as additional memory), suitabil- Most dot-matrix printers will also computer needs against your budget. ity of a particular computer dealer, and handle graphics. They provide a As you shop for a computer, keep in available financing. variety of print styles, and they will mind what you want the computer to Remember that the total cost of a meet most people's needs. do right now and what you want it to home computer system will include not only the initial hardware (CPU, CRT, • Will a technician make service calls Boot. The sequence of events that and tape or disk drive), but also at extra cost? enables a computer system to be software, and add-on hardware such as • How soon after purchase should you made operational—in effect, to reset a printer and modem. Computer expect delivery? or turn on the machine. • maintenance and repairs should be part • What are the payment terms? Byte. A group of 8 bits, usually treated of your considerations. • What kind of warranty does the as a unit. One byte can store one computer manufacturer provide? unit of information. Memory capac- Conclusions ity of a computer is measured in • Does the dealer offer any additional bytes. Plan to spend plenty of time with guarantees? your computer after you purchase it Cassette. A standard tape cassette, an • Will the dealer bench-test your new inexpensive way to store programs to learn new ways to use it. Remember: machine before you take possession? it promises to be an exciting new tool and data. • What kinds of problems can you for you. Before purchasing a home Character. Any information that can expect to have with your computer? computer, be sure you: be stored in one byte. Examples are • Does the store buy back equipment • have a good idea of what computer letters of the alphabet. applications you want and need; or make trades? Under what . Programs that circumstances? • check for information with friends allow the user to create geometric • Will the dealer accept telephone or colleagues who already own a shapes, intricateDATE. designs, and pic- computer; inquiries from new users who are tures, often in color. curious or confused about some Computer literacy. Understanding the • shop in different stores to compare aspect of their system? brands and models; and OFlanguage and functions of computers. • test the demonstration model for CP/M. A disk ease of use and understandable Some computer periodicals developed by , Inc., instructions. Byte that has become popular among McGraw-Hill Inc. microcomputer users. Here are some suggested questions P.O. Box 590 CPU. Central processing unit. The to ask your salesperson: Martinsville, NJ 08836 OUT heart of the computer, the CPU • How long has your store been in InfoWorld performs the basic arithmetic and business? CW CommunicationsIS Inc. logic functions and supervises the • What services does it offer (both 375 Cochituate Road, Box 837 operation of the entire system. In a before and after purchase)? Framingham, MA 01701-9987 , the CPU is a • Does your store carry software as Personal single integrated chip. well as hardware? Hayden Publishing Co. CRT/monitor/video screen. Cathode • How extensive is the product line? P.O. Box 2941 ray tube, the TV-like device that Boulder, CO 80321 • Does your staff have special exper- displays the computer commands, tise in a particular area (home use, Personal Softwareinformation: programs, games, etc. With less small business, games, etc.)? Hayden Publishing Co. expensive computers, a traditional 4 Disk Drive, P.O. Box 1473 TV is often hooked to the computer; • Are training sessions available? How Riverton, NJ 08077-7073 others use monitors designed just expensive, how extensive, and how for them. frequent are they? Computer terms Dedicated. Assigned to a single device The more you know about the These are some of the terms or purpose. dealer's policies, the easier it will be to commonly used by computer owners Disk or "floppy" disk. A flexible, make your buying decisions. Before currentand computer salespeople. These terms circular piece of plastic, coated with you buy, obtain answersPUBLICATION to the are intended to help you speak magnetic material, used to store and following questions: "computerese." retrieve programs and data. • Does the store have a repair facility? Access. The ability to communicate Disk drive. An electromechanical If not, who can service your with a computer or computer- device that stores information on, or computer? most connected equipment. recalls information from, a disk. • What is the policy on repairs? THIS Bit. The basic unit of computer . A set of • How long do repairs generally take? memory. An abbreviation for Wnary programs that perform the house- • Does the shop usually repair circuit digit, the term refers to a single digit keeping functions of a computer. boards or swapFor them for new ones? of a binary number—a 0 or a They control data transfer, file • Is a variety of replacement compo- 1—that is, the smallest unit of management, and data display nents available fromhttp://extension.oregonstate.edu/catalog stock? information recognized by a com- functions, among other things. • If not, where is the nearest supplier puter. For example, the binary Files. Organized collections of related and how quickly will the parts number 101 is composed of 3 bits. data stored on magnetic tapes or arrive? Baud. A measurement of communica- disks. Files can either be recorded • Is a computer like yours available tion speed between computers. For from the computer's memory or for loan while your system is in the example, 300 baud is about 30 retrieved by the computer from a shop? characters per second. disk and placed in its memory. Hard disk. A rigid disk made of hard, Personal computer. A small computer ROM. Read only memory. This part of plasticlike material, used to store based on a . Not all the contains the and retrieve programs and data. , however, are per- basic language instruc- Though more expensive than a sonal computers. A microprocessor tions. ROM is locked into the floppy disk, a hard disk is far more can be dedicated to single tasks as computer. It can't be erased, permanent and has much greater diverse as controlling a machine tool changed, or used by the programmer. storage capacity. or a . Run. When a computer is given a Hardware. All of the mechanical and Ports. The connections on a computer program to execute, the program is electronic components of a com- that allow it to interact with other said to be running. puter system—for example, elec- equipment such as printers or Semiconductor. An element, usually tronic chip, printer, monitor, etc. modems. silicon, that carries a positive or . A device or lever connected Printer. A device for producing paper negative charge. Semiconductor to the computer that moves objects (hard) copies of data output by a technology has made possible the around on a screen. Used with video computer. manufacture of extremely small games. Also referred to as & paddle. electrical circuits. Printer cable. A cable that transmits K. Kilo, a prefix meaning a thousand. Software. The programs and instruc- data from a computer to a printer. Used before the word byte to denote tions governing the operating of the memory capacity. Each kilobyte Program. A series of instructions computerDATE. that direct it to perform equals 1,024 bytes, but K generally is carried out by the computer in specific functions—in contrast to used to mean about 1,000. A typical sequence. The program must be hardware. personal computer has a memory written in a language the computer Store. To enter data into a memory ranging between 5 K and 256 K. understands. OFdevice. Keyboard. The typewriterlike mecha- RAM. Random access memory. The Surge protector. An electrical device nism on which computer commands part of the computer memory that is that protects computers from power are entered. Some computers come used to write programs and to store disturbances. with keyboards; with others, key- data in the form of variables. RAM User friendly. What all computer boards must be purchased separately. is gone when the machineOUT is turned "illiterates" hope for: a computer Keys can be raised, like those on a off. RAM is necessary to operate a system that is easy and nonthreaten- typewriter, or flat (printed on a CP/M program. ing to use and understand. plastic membrane). IS Variable. A quantity that may assume Language. Commands and statements one or many values. that, when put together, allow communication with computers. Examples are BASIC, FORTRAN, COBOL, and PASCAL. Logo. A programming language devel- oped to introduce children to using information: computers as problem-solving tools. Memory. A device or series of devices capable of storing information in the computer temporarily or per- The Oregon State University Extension Service provides education and information based manently, in the form of patterns of on timely research to help Oregonians solve problems and develop skills related to youth, binary 0's and I's. In many personal family, community, farm, forest, energy, and marine resources. computers, memory can be ex- Extension's home economics program offers educational opportunities to help individuals panded by adding hardware. currentand families manage their resources to meet needs for food, clothing, finance, shelter, Menu. A list of choicesPUBLICATION in a computer parenting, and human relationships. program displayed on the screen, to guide the user or.to indicate the This publication was prepared by Tim Cross, Extension computer applications contents of a disk. coordinator, and Suzanne Badenhop, former Extension family housing and energy management , Oregon State University. Trade name products and services are Microcomputer. A mostself-contained, mentioned as illustrations only. This mention does not mean that the OSU Extension THISdesktop computer whose central Service endorses these products and services or intends any discrimination against others processing unit consists of one or a not mentioned. few large-scale integrated units. Microprocessor.For A central processing Extension Service, Oregon State University, Corvallis, O. E. Smith, director. This publication was produced and distributed in furtherance of the Acts of Congress of May 8 unit that is composed of one or more and June 30,1914. Extension work is a cooperative program of Oregon State University, semiconductorhttp://extension.oregonstate.edu/catalog chips. the U.S. Department of Agriculture, and Oregon counties. Modem. Derived from the words Oregon State University Extension Service offers educational programs, activities, and modulate and cfemodulate. A device materials without regard to race, color, national origin, sex, or disability as required by attached to the computer to convert Title VI of the Civil Rights Act of 1964, Title IX of the Education Amendments of 1972, the computer's digital signals for and Section 504 of the Rehabilitation Act of 1973. Oregon State University Extension transmission to other computers Service is an Equal Opportunity Employer. over telephone lines.