Professor P.C. Laptop! is a tutorial system which provides hundreds of amazingly useful tips, tricks and reference articles about the wonderful world of laptop and notebook computers. In a way the Professor is simply a book on a computer disk. But Professor P.C. Laptop! offers more speed, flexibility and FUN than any printed book. A LARGE amount of practical reference material has been packed within this program. The best thing to do is take your time since you can always come back to the Professor for a paper printout or to search for that tip or idea using the powerful software utility tools built right into the program. If you are at the main menu, use the cursor direction keys (arrow up, down, right or left) to move to any menu item then press the return or enter key to open a tutorial section. Once you are reading a tutorial use the PAGE UP (Pg Up) and PAGE DOWN (Pg Dn) keys to move up and down through a tutorial - just like turning pages in a book. Within any tutorial, the F1 help key tells how you can control colors, turn sound on/off, search through the tutorial for a title or phrase, print entire sections on your printer and more. In fact, try pressing the F1 key right NOW and glance at the help screen for a preview of the special tools and functions you can activate from within any of the tutorials. While reading any tutorial, a reminder line appears at the BOTTOM of the screen to provide helpful hints. When you reach the END of a tutorial, press the escape key to return to the main menu. Press escape key NOW to return to the main menu and select a chapter or tutorial section of interest to you. Professor P.C. Laptop! Version 5.8 (c) 1992 A tutorial for laptop, notebook and portable computers A shareware package from Jim Hood & Seattle Scientific Photography POB 1506, Mercer Island, WA 98040 (206) 236-0470 CIS: 72020,2176 Suggested BBS name: LAPTUT58.ZIP ---------------------------------------------------------------- How to install: this software must first be installed prior to use. Type the command INSTALL . You may install to or from a hard drive or floppy drive. How to run: after installation, start the program with the command GO DESCRIPTION Professor P.C. Laptop is a comprehensive tutorial system which provides laptop, notebook and portable computer owners (or those interested in buying a laptop or notebook) hundreds of powerful tips, tricks and reference articles. Tutorials include: travelling with laptops and notebooks, clever equipment purchasing strategies, battery care and maintenance, telephone and manufacturer support numbers, software selection, DOS lessons, history of computers, hard drive secrets, laptop batch files, modem use, little-known CompuServe resources for laptop owners, custom reading list, computer virus protection methods and more. An amazing collection of laptop and notebook computer reference material! Contains high speed search system, capability to turn sound on/off, tutorial printing, help screens and color or monochrome light bar menus. Written by shareware author Jim Hood whose PC-Learn and $hareware Marketing $ystem software packages have become instant classics! Registration brings four special bonus disks for laptop and notebook users. This software has no special requirements: it will work on floppy or hard drive equipped computers. Color or monochrome and all screen resolutions (Herc, CGA, EGA, VGA.) Package registration ($20.00) brings four bonus disks. FILES ON DISK (Prior to installation) README General information, this file INSTALL COM Installation file REGISTER TXT Registration form PART1 EXE Tutorial files part one PART2 EXE Tutorial files part two PART3 EXE Menu system for tutorial PART4 EXE Configuration data for single drive installation PART5 EXE Configuration data for dual drive installation LHATXT EXE Documentation on LHA file archiving system (After installation) README General program information GO BAT batch file to run program BOOK CFG configuration for single drive systems BOOK1 CFG configuration for dual drive systems BOOK2 CFG configuration for dual drive systems LAPTOP EXE Menu system for tutorial ORDER EXE Automated order/registration program ORDER FRM Text file for order/registration AUTHOR TXT Author background BATCH TXT Batch file tutorial BATTERY TXT Nicad battery tutorial BIBLIOG TXT Bibliography, reading list BRIEF TXT Introductory program notes CIS TXT Special CompuServe laptop tips CLUB TXT Computer club info and mailing list DOS1 TXT Beginner DOS laptop tutorial DOS2 TXT Advanced DOS laptop tutorial EQUIP TXT Buying a computer or laptop notes HD TXT Hard drive tutorial HISTORY TXT History of computers INTRO TXT General introduction to computers MODEM TXT Using a modem REGISTER TXT Registration information SOFTWARE TXT Selecting software SUPPORT TXT Manufacturer telephone list TIPS TXT Tips for using computers TRAVEL TXT Travelling with a laptop VIRUS TXT Dealing with virus infections Installation of this shareware tutorial on laptop computers by computer stores and VAR's is encouraged. A single copy registration is required for this use although multiple copies can be installed on MANY machines at no additional cost by computer stores, retailers and VARS who FIRST pay a single copy registration fee. Registration ($20.00) brings the following FOUR bonus disks: ONE DISK containing additional powerful laptop and notebook utilities and custom programs to increase the usefulness of your computer. If you like the tips, ideas and training from this software package you NEED this disk collection of software to bring your laptop to its full potential! Plus you also receive... ONE DISK containing the latest version/update of the massive PC- Learn computer tutorial, a much larger computer tutorial system. Whether you are a beginner or more advanced user, PC-Learn contains MANY MORE detailed tips and training tutorials you can use with your laptop. Plus you also receive.... ONE DISK containing an unregistered version of ULTIMATE POWER TIPS, VOLUME ONE. Hundreds of power user secret tips for effective computer use: Windows, spreadsheet, batch files, equipment repair secrets, word processing shortcuts, macro ideas, modem and telecommunication tips and more! Plus you also receive.... ONE DISK containing the latest REGISTERED version of Professor P.C. Laptop! in case you have an old version of this package. And finally you receive.... A registration certificate and registration number to validate your legal right as a fully registered user of Professor P.C. Laptop. Site, LAN licenses and CUSTOM PROGRAMMING MODIFICATIONS of this tutorial for corporate or business training are available. Maybe you want to add something about your office LAN, use of laptops by sales personnel, the layout of your business spreadsheet templates, etc. Contact the author. Special arrangements are available for non-profit users such as job training centers and minority education programs. Purchase orders from corporations are accepted. The program can be CUSTOM adapted to revise, remove or add tutorials for your specific sales, training and equipment strategies. Contact the author. If you are new to computers you may not have heard the term SHAREWARE. Basically this means an author or group has prepared a software program which you are free to copy and share with others, but the author of this software requests a REGISTRATION FEE. The idea is that if the program is useful you evaluate it for a limited period (usually 30 days) and then become a legally registered user of the program by paying the registration fee. If you do not wish to register, you are expected to cease using the program. Shareware is an honor system. Are you registered if you "found" this tutorial already installed on your computer or purchased it from a computer club or shareware disk vendor or other retailer? Probably not. ONLY registered owners receive a printed registration with unique registration number and four special diskettes. You can ONLY become a registered user by mail through the program's author. This package is shareware which means try before you buy. It is acceptable to copy and share it with friends - but only registered PAYING users receive the bonus disks, registration certificate and latest update. The sole owner of this software package is Seattle Scientific Photography and Jim Hood who assume no liability, intended or otherwise, for the use or misuse of this package or the information or software code contained within. No warranties are offered, either expressed or implied. Your rights in this respect may vary from state to state. You are granted a limited license to copy and use this shareware software for a 30 day evaluation period pending your possible submission of a registration fee which brings additional benefits and a legal registration license as noted above. RECEIVE FOUR SOFTWARE DISKS AND LATEST UPDATE FOR ONLY $20.00 ---------------------------------------------------------------- What does your registration purchase, payable to the author of this program, bring to you? For $20.00 you receive FOUR exceptional software diskettes packed with VITAL laptop computer software! Note: four bonus disks provided if 360K format, 5.25 inch size disks ordered. Otherwise expect two bonus disks, 720K format, 3.5 inch size. The higher density 3.5 inch disks hold more programs so you will receive fewer disks but the same amount of software. Here's what you receive for $20.00: ONE DISK containing additional powerful laptop and notebook utilities and custom programs to increase the usefulness of your computer. If you like the tips, ideas and training from this software package you NEED this disk to bring your laptop to its full potential! Plus you also receive... ONE DISK containing the latest version/update of the massive PC- Learn computer tutorial, a much larger computer tutorial system. Whether you are a beginner or more advanced user, PC-Learn contains MANY MORE detailed tips and training tutorials you can use with your laptop. Plus you also receive.... ONE DISK containing an unregistered version of ULTIMATE POWER TIPS, VOLUME ONE. Hundreds of power user secret tips for effective computer use: Windows, spreadsheet, batch files, equipment repair secrets, word processing shortcuts, macro ideas, modem and telecommunication tips and more! Plus you also receive.... ONE DISK containing the latest REGISTERED version of Professor P.C. Laptop! in case you have an old version of this package. And finally you receive.... A registration certificate and registration number to validate your legal right as a fully registered user of Professor P.C. Laptop! Installation of this shareware tutorial on laptop computers for resale by computer stores and VAR's is encouraged. A single copy payment ($20.00) is required for this use although multiple copies can be installed on MANY machines at no additional cost by computer stores, retailers and VARS who FIRST pay the registration fee. Site, LAN licenses and custom programming or adaptations of this tutorial for corporate or business training are available. Maybe you want to add something about your LAN, use of laptops by sales personnel, the layout of your spreadsheet templates, etc. Contact the author. Special arrangements are available for non- profit users such as job training centers and minority education programs. Purchase orders from corporations are accepted. The program can be CUSTOM adapted to revise, remove or add tutorials for your specific sales, training and equipment strategies. TO REGISTER, a $20.00 fee is requested and appreciated! See the registration option elsewhere from the main menu, or execute the command ORDER which automatically processes the order form which is a file named ORDER.FRM. You can also activate the automated order program from the main menu which allows you to print the registration form. If you are new to computers you may not have heard the term SHAREWARE. Basically this means an author or group has prepared a software program which you are free to copy and share with others, but the author of this software requests a REGISTRATION FEE. The idea is that if the program is useful you evaluate it for a limited period (usually 30 days) and then become a legally registered user of the program by paying the registration fee. If you do not wish to register, you are expected to cease using the program. Shareware is an honor system. Are you registered if you "found" this tutorial already installed on your computer or purchased it from a computer club or shareware disk vendor or other retailer? Probably not. ONLY registered owners receive a printed registration with unique registration number and four special diskettes. You can ONLY become a registered user by mail through the program's author. This package is shareware which means try before you buy. It is acceptable to copy and share it with friends - but only registered PAYING users receive the bonus disks, registration certificate and latest update. ---------- TRAVELLING WITH A LAPTOP COMPUTER ---------------------------------------------------------------- Laptops are made to travel. Their small size and potent features make computing on the road a snap. Consider using this assortment of tips which seasoned laptop owners have come to rely on.... Airports are a frequent transit point for laptop owners. Be sure to be prepared for a SPEEDY passage through airport security by being aware that in most cases you MUST boot up the laptop so that a DOS prompt, menu or other sign of visible activity is displayed on the screen. Security officials do this for a reason: if a laptop computer has been tampered with or hollowed out to serve as an empty shell for explosives or weapons, the machine will not boot up or operate. By forcing the laptop owner to activate the machine, airport security is effectively screening for tampered machines. Once you know this, several important tips are quite useful. Always carry a BOTH a fully charged battery and AC adapter with the laptop. No power means no possibility of booting the machine and your laptop might be forced to remain behind! To speed the process on laptops equipped with hard drives try an experiment. Prepare a bootable floppy disk with DOS system files and a short AUTOEXEC.BAT program which boots the machine rapidly since DOS usually tries to boot from a floppy first and then the hard drive second. Now time how long it takes to boot from the floppy as well as the hard drive. Whichever is faster is the one you want to use to speed your trip through airport security. But ALWAYS take the bootable floppy as well. Why? If your laptop hard drive becomes damaged in transit - a possibility in today's airport environments - then you have a floppy backup which will also get you through airport security. Cursor size and blink rate on many laptops are atrocious. Third party software utilities are available which can alter both size and shape of the cursor - we will discuss these in more detail in the software section of the Laptop tutorial. However the point to be made is that you might find one ideal cursor size and blink rate for airplane use and a DIFFERENT cursor size and blink rate better at the office or in the airport. Try various combinations in various lighting. Several different cursor configurations are quite handy when travelling under varying lighting conditions. By the way in a pinch, The WordPerfect word processing package has just such a utility you might want to dig out if you own WordPerfect but have never used software cursor control utility! Did your portable printer malfunction and crash while you are on the road? Or maybe you just don't want to carry your printer at all. Here's an obvious idea: use your laptop and modem/faxboard to fax your file to the hotel front desk fax machine and pick it up there! If your modem lacks fax transmit capability, send the file via modem to CompuServe and let them re-send it to your hotel fax machine using their fax transmission capability. Worried that the fax image might fade or curl with heat or handling? Then xerox copy it onto standard paper which is a more permanent material than fax paper. Speaking of modems, the smallest and most "laptop useful" modems are available from U.S. Robotics (call 708/982-5010.) Their World Port modem is truly tiny, fully-featured and ruggedly designed for travellers. Hayes has also produced the Pocket Modem (call 404/449-8791.) Some of the most clever portable modems do not even need battery power - they draw current from the computer or telephone line. Hotels and airlines always have carpeting. And carpeting is productive of electrical static. Shuffle across the floor in most travel facilities on a dry or cool day and you get a spark when you touch the doorknob. This same static electricity buildup can ruin the EPROM chip in your laptop keyboard when you sit down to use the laptop. Be sure to first touch a bathroom faucet with a coin. To eliminate static in your hotel room, just take off your shoes and socks! Carry extra charged batteries on long flights or international flights. Seems like a simple tip, but that battery pack you bought two years ago may finally decide it has a one hour life somewhere over the Atlantic Ocean. Rechargeable batteries cannot be recharged forever - after two to five years they begin to die. Be sure you know how to turn off the speaker beep facility in your laptop. Crowded airplanes indicate courtesy. Third party software utilities exist which will provide this capability if you own an older laptop without this software or hardware feature. More about this in our software tutorial. Conserve power on long flights. Turn down the screen brightness to save power. Use the auto-resume feature if your laptop contains the capability. Switch to slow mode or lower the processing speed of your CPU chip. Your instruction book may mention some or all of these features. Some laptops have a variation of the auto resume feature that even allows you to change batteries right in the middle of a program. Check your manual. Might be a lifesaver on a plane trip. Save still more power when travelling by investigating software ram disks or virtual disks which, unlike a spinning hard drive or floppy, use far less power on long airline flights. DOS itself comes with a reasonable although rudimentary ram drive called VDISK which all laptop owners should check out. You can also obtain third party shareware, commercial and public domain ram disk software. Of course be sure to save your work to a floppy or hard disk before you turn the machine off since a ram disk operates purely in memory and MUST have power to maintain your data. If you travel out of the country, be sure to register your foreign made laptop with U.S. Customs when you depart - so that upon return you are not forced to pay duty on a machine you bought in the U.S. but which customs officials will suspect was purchased overseas. This can be a sticky subject. Contact a local customs office for instructions on registering your machine prior to departure. Travellers should also consider etching your name, address, telephone and social security number onto the machine in several places. Although this may decrease the resale value of the laptop, it also increases chances of recovery in case of theft. Don't make the mistake of etching ONLY your social security number onto your laptop. Federal privacy laws prevent release of your social security records even to some law enforcement agencies and in that respect having only your social security number on valuable items is probably next to worthless as a security item. Hotels are getting better about providing modular plug in telephone jacks for laptop users who need to hook up a modem. But it seems the telephone jack on the wall is always ten feet from the nearest table where you laptop sits. Solution? Always bring a modem extension cord with in-line connector. Makes laptop modem work a joy! Another tip: use the hotel's toll free 800 number to call ahead and doublecheck that your room is wired with modular plug-in telephone jacks. Takes a moment and costs you nothing! Speaking of plugs, investigate the new breed of miniature surge supressing AC adapters if you travel to foreign countries whose voltage can be less reliable than that in the U.S. You can obtain special anchor plates or straps which attach to the bottom or side of a laptop with permanent glue. A flexible steel cable and lock lets you secure your laptop to a hotel radiator or piece of furniture and defeats all but the most determined thief. For those who absolutely need telephone links when travelling, consider purchasing an acoustic modem coupler which works with all telephones when you cannot plug your modem into the wall. Acoustic couplers work by attaching directly to the mouthpiece and earpiece of any standard phone and transfer data directly by sound transmission. By the way, in overseas areas you will soon find that you need a maddening array of special adapters to hook your modem to the telephone line directly. An acoustic modem coupler is the only truly "universal" adapter which will connect to all telephones throughout the world. Another modem tip when using hotel telephone lines: arrange with the front desk or operator to ALWAYS put your call DIRECTLY through without intervention. Many hotel system route your call through a switchboard which prevents your modem from getting a dial tone! Diehard laptop users who communicate with the head office via modem should also investigate remote computing software which we will discuss later. Remote computing software allows you in your hotel in New York to call San Francisco by modem and then connect directly with your desktop computer or office LAN network. Once connected, you can run your word processor, obtain files, check figures on the office spreadsheet and more. In essence your laptop functions as a remote keyboard for a computer which is thousands of miles away. Shareware, public domain and commercial software packages of this type are available. But if you do this, here is one important tip many travellers learn the hard way: ALWAYS leave a note for the maintenance person or janitor which tells them not to turn off what appears to be your idle office desktop computer. Oh, and while you are gone, turn off the desktop monitor but leave on the pc if you plan to compute remotely. This saves power and prevents screen burnout! Need to test if two files are slightly different as you check newer document files against older ones? Or maybe just backup all NEWER revisions of your files to a floppy or transmit them by modem to the head office? Use the DOS XCOPY command to track down differences between two files such as word processing documents. DOS also previously had an older File Compare command called FC which accomplishes the same thing. Sidekick version 2 has a reconcile feature and Lap-Link can transfer files between to computers and check dates and times to make sure you are obtaining the newest version of a file or to ensure that both computers indeed have the latest file. By the way, here is an example of how to use the DOS XCOPY command to copy all files from ALL subdirectories on a laptop hard drive named C: onto a backup floppy in the A: drive which have been updated on or later than March 15, 1992. Very handy when you are on the road and want to copy or prepare for modem transmission all of your updated files for the head office. At the DOS prompt type: XCOPY C:\*.* A:/S/D:03/15/92 Consider travel insurance for replacement of your laptop in case of theft. Contact Safeware at 800/848-3469. Business travellers often have to present VERY important presentations with their laptops. Essential job proposals, contracts, crucial price schedules. If it is important to your business, always make a backup copy on floppy disk. Seems simple, but many business users discover that their hard drive equipped laptop has crashed due to airport handling in transit. A floppy can save the day and in a pinch you can rent a computer or borrow one from your client. If data matters, put it on a floppy. Make sure you ALWAYS carry a null modem cable and file transfer software with your laptop when travelling. You can probably patch into another desktop computer to transfer files in emergency, but without the null modem cable and software you are stuck. Practice transferring files between several computers before you travel so you have the process comfortably memorized. For the truly worried traveller, also carry a pair of gender changer plugs which allow hookup of male to male and female to female cable connections. Also a 25 to 9 pin plug adapter. Laptop computer die in transit? Carry a set of jewelers screwdrivers and floppy disk cleaning kit. If a few simple things such as this won't fix it, then grab the yellow pages and look under computer rentals. By the way, many hotels maintain rental laptops for business travellers. But the secret is that the rate is far cheaper by renting from a local vendor than the hotel. Make a few phone calls and get a laptop delivered to your hotel suite in case of emergency. The smartest travellers call ahead to their destination and reserve a backup laptop in case of problems at a local vendor. If the laptop is not checked out a small retainer fee is kept by the vendor. This can be done by a charge card and a long distance phone call. Same goes for renting LCD projection panels for business meetings. Consider obtaining a CompuServe account for modem use if you travel frequently. You can obtain online support for laptop computer problems directly from the manufacturer, download special software utility files, transmit important files to the home office, send faxes when all you have is a modem which lacks fax transmit capabilities (CompuServe converts your modem transmission and sends it on via their fax equipment.) Lots of good ideas and special laptop discussion forums for business travelers. You can even book hotel and airline reservations directly by modem using CompuServe, too. Laptops, travel and CompuServe go together handsomely. Did your ribbon die in your portable printer? Just not black enough? Stick some fax paper in the printer. It is heat sensitive and will frequently pick up an image without a printer ribbon. Amazing but true. This works with dot matrix printers. Do not try it with laser printers. Check ahead for special regulations. Example: in Germany modems are regulated under certain security laws - presumably spies could use them to transmit data. You must have a "modem permit" in that country or your equipment can be confiscated. In other countries and some developing nations such as Africa and India confiscation of computer equipment is common - even if all of your registration and travel documents are in order! In those cases you might be better off leaving your computer at home and bringing a tape recorder or notepad. Just because you own a computer does not mean you can use it in an unrestricted fashion while you travel! Tempted to use one of those inexpensive overseas power convertors to adapt your AC plug in convertor to European current? DON'T DO IT without first checking with the manufacturer. Those inexpensive current convertors work fine when changing high voltage overseas current to lower voltage US current for things like shavers because they reduce the voltage. The problem is that most of the world uses 50 cycle AC current versus the normal 60 cycle AC current in the U.S. Computers CANNOT run from these inexpensive convertors and damage may occur. Find out what device the manufacturer supplies or recommends for travel outside of your country of residence. Tutorial finished. Be sure to order your FOUR BONUS DISKS which expand this software package with vital tools, updates and additional tutorial material for laptop users! Send $20.00 to Seattle Scientific Photography, Department LAP, PO Box 1506, Mercer Island, WA 98040. Bonus disks shipped promptly! Some portions of this software package use sections from the larger PC-Learn tutorial system which you will also receive with your order. Modifications, custom program versions, site and LAN licenses of this package for business or corporate use are possible, contact the author. This software is shareware - an honor system which means TRY BEFORE YOU BUY. Press escape key to return to menu. RECHARGEABLE BATTERIES AND LAPTOP COMPUTERS ---------------------------------------------------------------- No other topic seems to inspire more opinion and comment than the proper care and handling of rechargeable laptop and notebook computer batteries. Should you slow or fast charge them? What is the true life of a rechargeable battery after which it must be disposed? Do rechargeable batteries have a "memory" effect? Can nickel-cadmium batteries explode when charging or discharging? Although this tutorial may seem technical in places, try to read ALL of it since battery power may be your only source of laptop power on many occasions. For many portable computers a variety of rechargeable battery options exist today. But frequently it comes down to the old standby: nickel-cadmium batteries. Ubiquitous in consumer electronic items such as shavers, flashlights, toothbrushes and radios, nickel-cadmiums or "nicads" are a reasonable balance of power, cost and weight and are used by many computer manufacturers as the portable power source of choice. Let's scratch the surface on the topic since there is QUITE A BIT the manufacturer doesn't tell you about nicads.... Glance at the following chemical equation which is at the heart of the nickel-cadmium cell reaction. Don't get overly anxious because high school chemistry was not your favorite subject. We'll take things slowly.... <----- Cd + 2 NiOOH + 2 KOH -----> Cd(OH) + 2NiO + 2 KOH 2 In this highly simplified reaction sequence, electricity is generated when the reaction proceeds in the direction of the right pointing arrow, the discharge cycle. If the reaction proceeds in the left direction the cell is charging. In simplest terms, a nicad cell (a battery is constructed of several cells hooked together) has a positively charged plate of nickelic hydroxide and a negative plate of metallic cadmium. The liquid between the positive and negatives plates which facilitates this chemical reaction is usually a dilute solution of potassium hydroxide - similar to lye or the Draino (tm) solution your pour down the sink to clean your plumbing. When discharging and thus producing electricity, the nickelic hydroxide is reduced to nickelous hydroxide as hydroxyl ions from the potassium hydroxide electrolyte combine with the cadmium metal of the negative plate of the cell to form cadmium hydroxide. Cadmium is oxidized when this happens and electrons are provided into the external circuit, such as your laptop computer. When charging, the process reverses and hydroxyl ions combine with the nickel which accepts electrons from the external charging circuit. Notice that the electrolyte, potassium hydroxide is unchanged with two atoms or units produced on both sides of the chemical equation whether charging or discharging. This is why you do not need to add more water to a nicad battery which operates as a sealed reaction container. It regenerates its electrolyte in both the charge and discharge cycles. All of this is an ideal nicad cell. The real world of computers and rechargeable batteries is not quite that simple. The first SERIOUS item to consider is that all nicad cells and batteries generate gas during both the charging, and to a lesser extent, discharging cycle. During recharging, oxygen gas is generated at the positive electrode while hydrogen gas is produced at the negative electrode. In other types of rechargeable cells, a standard lead acid car battery for example, these gasses are usually released into the atmosphere. The nicad cell does not have this luxury since it must operate cleanly and with minimum release of gasses or liquids. To minimize hydrogen gas release, nicad cells usually have an oversized negative electrode which tends to reabsorb hydrogen gas. In addition oxygen is recycled by combining with metallic cadmium to produce cadmium oxide. So called "fast-charging" nicad cells prevent gas buildup and dissipate some of the heat generated during the quick charge cycle by further enlarging the electrodes. Heat and gas buildup is thus controlled and kept to tolerable limits in quick charge nicads. The first of several lessons which can be derived from this technical discussion is that the buildup of hydrogen and oxygen gas during the charging cycle is normally dissipated unless HIGH recharging rates are attempted or unusually high temperatures are produced. If the nicad cell is charged at abnormally high rates the oxygen gas cannot dissipate and will EXPLOSIVELY rupture the cell. A safety system of sorts exists within the design structure of most nicad cells via a pressure venting system - a plastic diaphragm membrane at the top of the cell and small external hole or "exhaust vent." In theory the system safely vents excess pressure and then reseals. In practice the resealing is never complete and the cell may continue to ooze caustic electrolyte or worse the vent may not open soon enough and the cell may simply explode. The vent is really designed for SEVERE charging or discharging rates. In normal use it should NEVER activate; if it does, the battery should be discarded. In cases of massive overcharge or discharge the safety vent is usually too little too late and a dangerous battery explosion takes place anyway. During rapid discharge - short circuiting the nicad cell or battery with a piece of wire, for example - gas buildup and heat can be generated and a violent explosion can occur. Another reason why nicads can explosively burst when short circuited and forced to discharge quickly is that they have relatively low "internal resistance" which allows them to dump their electrical capacity quickly and with explosive force. Common zinc carbon batteries have a much higher internal resistance and when shorted may produce serious burns to your fingers from melting wire but usually will not explode due to sudden gas buildup. On the point of sudden nicad discharge by short circuit you might be tempted to say that it would be highly unlikely with a portable computer battery. Not so. Tales are told of laptop computer batteries which have exploded when a careless owner shoved several fully charged nicad batteries in a travel case with a set of spare keys. If the keys accidentally contact both the positive and negative poles of the nicad simultaneously, a violent explosion reaction can occur! Clearly nicads have some unusual features to be respected and understood. Be careful with charged nicads and treat them as the small "hand grenades" which they can become. Heat, sudden short circuits and high rates of charging are the problem in this area. The correct operating temperature for discharging and recharging nicads is from 65F to 85F, according to most manufacturers. High and low ranges of from +32F to 115F are possible as upper and lower limits if nicads MUST be used in extreme environments although discharge and recharge efficiency may be adversely affected - it may require more power to fully charge the battery, charge may not be held for as long on the shelf after charging and finally discharge may not produce a full three or four hour computing session at these severe temperature ranges. Electrically, individual nicad cells - the units which are hooked together to produce the final battery - have a charged voltage of 1.25 volts. Nominally this drops to 1.2 volts under actual discharge use or "load" in the electrical device. Individual cells are strung together in "series" with the positive terminal of one cell touching the negative terminal of the next cell in sequence to raise the voltage to that suitable for the electrical device. Thus two cells hooked in "series" as a battery produce 2 X 1.2 volts = 2.4 volts. Likewise, three cells connected as a battery produce 3.6 volts. By the way, ordinary flashlight batteries of the carbon zinc type have a nominal voltage of 1.5 volts compared to the 1.2 volts of the nicad cell. Nicad batteries have an unusual and highly characteristic discharge behavior which is best described as "a stable discharge plateau then sudden voltage drop." Essentially a fully charged nicad battery provides constant voltage and current until near its exhaustion at which point the voltage SUDDENLY DROPS and the cell is, for practical purposes, completely discharged. Compare this to standard carbon zinc and alkaline batteries which gradually drop in voltage and amperage through the discharge cycle of the battery. In use nicads tend to be stable, then die suddenly at the end while conventional non-rechargeable batteries slowly decay in voltage as their power is consumed. One conclusion you might draw from this is that when your portable computer beeps that the nicad battery voltage is nearing exhaustion you literally have only moments of use left! The good news is that nicads produce dependable power through their discharge cycle which is highly desirable with digital data and computer memory devices. The "memory effect" of nicads is perhaps the most discussed and misunderstood phenomenon associated with nicad cells and batteries. An undesirable and somewhat unique characteristic of nicad batteries that they can develop a "memory" which can decrease either the capacity or voltage of the battery. The first type of memory problem in nicads - voltage memory - is caused by sustained charging over many days or months. This memory effect can be accelerated by high ambient temperature extreme duration of charge and high rate of charge. In effect the battery is charged for such a long period of time or at such a high rate or high temperature that the efficiency of the chemical reaction is impaired and proper terminal voltage readings are not achieved. In the second, more common "memory capacity" problem, the nicad loses the capability to deliver its full power capacity. One cause of this peculiar memory problem is the FREQUENT PARTIAL DISCHARGE of the battery - use for perhaps 30 minutes - and then full recharge again. In effect the nicad battery "learns" that only part of its capacity is used and over several cycles of "partial depletion and then full recharge" that less then full capacity is needed. It will then be unable to deliver a full two or three hour standard discharge in normal use. Fortunately memory effects are usually temporary and can be reversed. The chemical basis for these two memory effects is not fully understood, but may have to do with obscure oxidation reactions which temporarily coat the internal electrodes of the battery with thin layers of complex non-reactive chemical compounds which can be removed by more fully "exercising" a nicad through a complete charge/discharge cycle. It is claimed by many manufacturers that this odd memory effect of nicads has been largely eliminated due to modern manufacturing methods. However to some degree this may in fact be a result of newer charging systems and the relatively complete discharge of nicad power by modern laptops. In effect the batteries are charged and discharged in a more appropriate manner by most laptop users so memory effects "appear" to be no longer a problem. Both memory problems - voltage memory and capacity memory - are usually temporary and can be corrected by discharging the battery to or very near its exhaustion point (optimum drawdown voltage is about 1.0 to .9 volts for a standard 1.2 volt nicad) and then recharging it to full capacity. Repeat this discharge- recharge cycle from 2 to five times and frequently the nicad will lose its memory for the "partial capacity" and again provide a full 3 or 4 hours of use in most laptops. Actually, frequent FULL discharge and recharge prolongs the life of a nicad. The more you use them the longer they last! Most folks who want to completely discharge laptop nicads simply leave the computer on until it runs down. A much faster method is to use the following batch file which continuously reads the directory of a disk and writes the contents to a disk file. The continuous disk access drains nicad power much faster. If you are not familiar with batch files, read the batch file tutorial elsewhere in this program. Here's the three line batch file. To stop the batch file at any time press the control and break keys simultaneously. When finished you may wish to erase both the batch file and the small file named "test" which it creates. :start dir>test goto start As an aside, the newer nickel-hydride batteries used in some laptop and notebook computers do not seem to suffer from memory effects. But these batteries are more expensive and not in common use by most laptop manufacturers. Nicads do eventually fail. And for various reasons. Temporary or partial failure due to memory effects was discussed in the previous paragraphs. Permanent failure - usually between 3 to 5 years into the life of a typical nicad can happen due to the growth of characteristic "whiskers" of conducting chemical compounds which effectively bridge the internal gap between the positive and negative electrodes inside the battery. Effectively these small contamination deposits gradually short circuit the battery internally which leads to inability to charge or discharge. Some clever electronic hobbyists build high current "surge" power supplies which can burn open these internal deposits and reopen the gap between positive and negative electrodes. A risky practice at best - given the explosive reputation of nicads - but "zapping" nicads in this manner has been documented as one way to add life to an otherwise dying battery. A risky an usually ill-advised attempt to salvage an otherwise dying battery. A different permanent failure can result from premature loss of the liquid electrolyte from the battery. High temperature and/or high charging rates are usually the cause here. Quick-charge batteries frequently fail due to this problem if their charging circuits are not properly designed. If the top edge of the cell which contains the fail safe pressure release valve has a buildup of white corrosion powder this is probably the residue ot the expelled electrolyte and the cell may be on its way to failure and should be replaced. Note that you can only see this corrosion buildup on the top of the SINGLE nicad cells which are usually encased within a surrounding plastic battery housing. The plastic housing may show little problem externally. Generally, however, the average computer user should not attempt to open the protective plastic case of the battery to examine each cell. If the manufacturer seals several individual nicad cells in a plastic battery container it is for GOOD reason and your own personal safety. As a rule quick charge nicads do not last as long a regular nicads due to heat build up during the charging cycle. So how long will a nicad battery last before complete failure occurs? Manufacturers estimate LOW figures between 500 and 1,000 full charge and discharge cycles or about 3 to 5 five years, as noted above. Some nicads have been known to approach 5,000 to 10,000 charge and discharge cycles before permanent failure. Excessive quick charging, heat buildup, infrequent use and lack of full charge all contribute to shortened nicad lifespan. Charging and discharging mathematics... Charging nicads is generally done automatically by a charging circuit. Two practical pieces of advice: 1) if the battery becomes VERY hot something could be wrong 2) if the manufacturer tells you that the battery will be fully charged after a certain length of time although it can be left charging longer you will probably do the nicad a favor by removing it after full charge is reached. Some clever nicad users simply attach an inexpensive electrical timer - similar to those used to turn lights on and off in the evening - directly to the nicad charger to prevent overcharging. Generally nicads have a proper charging rate which depends on each manufacturers recommendation. For standard nicads which are NOT quick charge types the proper slow or "trickle" charge rate is determined by dividing the ampere hour capacity of the battery by 10. For example if a nicad has a total capacity of 1 ampere hour, dividing this by ten (1/10) produces a correct trickle charging rate of .1 amps or 100 milliamps. Quick-charge nicads can accept a charge rapidly and the suggested charging rate is determined by dividing the ampere hour capacity of the battery by 3 rather than by 10. These figures represent the trickle charge rate which theoretically means the nicad "could" be safely left charging indefinitely without harm. Higher efficiency chargers are designed not to simply trickle charge nicads but start a discharged battery at a HIGH rate of charge and then taper the charging current back quickly to the safer "trickle" charge rate once full charge is reached. Usually for regular nicads this "initial surge charge" can be as high as the ampere hour capacity divided by 3. For quick charge nicads this "initial surge charge" can be as high as the ampere hour capacity divided by 1. Obviously these are very high charge rates and are provided to discharged batteries and then quickly discontinued once full charge is approached. Clearly a charging circuit of this sophistication is expensive and may even contain its own microprocessor to sense the discharge level of the nicad and calculate the optimum charge rate, time and trickle charge transition. Since we have previously discussed the adverse affect of heat on nicads it is essential to note that NICADS SHOULD BE CHARGED IN A COOL OR ROOM TEMPERATURE location since they normally generate heat when charged. If you minimize heat buildup - especially during the charging cycle - you will prolong the useful life of your nicad battery. Discharging a nicad - especially if you are trying to remove a "memory" problem such as that discussed earlier does NOT mean discharging a cell to zero volts. Usually the correct discharge voltage is about 1.0 volts. This may seem odd when you consider that the fully charged cell has a 1.2 volt reading, but in fact at 1.0 volts a typical nicad cell has released about 90% to 95% of its energy - another eccentric, but predictable behavior of nicads given the rapid "voltage drop off" as they near the end of their three or four hour life in a laptop computer. Shelf life. While carbon zinc and alkaline batteries can hold their charge for years, nicads lose their charge relatively quickly. Although it varies, one quick rule of thumb is that a typical fully charged nicad will lose roughly 25% to 35% of full charge in one month. Then another 25% to 35% of THE CHARGE REMAINING in the next month. And so on and so on. Thus if you have several nicad batteries you want to charge for a trip you will be taking in a month, it is probably better to charge ALL OF THEM the final week just before the trip rather than the month before. For want of a better phrase, this might be called "shelf discharge" and is normal with all nicads and has to do with slight electrical leakage and chemical compound decay internally within a charged nicad which sits on a shelf. Cooling or refrigerating the nicad (but NOT freezing) will slow this "shelf discharge" since you are cooling and slowing the breakdown reaction. In fact ALL batteries will last longer when refrigerated until they are used. Simply store them in individual sealed plastic bags (to minimize moisture condensation) and place them in the refrigerator. And so we conclude with a little summary.... 1) Do exactly what the manufacturer suggests for both discharging and recharging a nicad. 2) Keep temperatures - especially during charging - cool or at normal room temperature. 3) Never short circuit a nicad intentionally or accidentally. 4) Try cycling a nicad through several COMPLETE discharge and recharge cycles if it "appears" to be faulty an incapable of operating your equipment for a normal three or four hour operating period. 5) Remove nicads from charging circuits or discontinue charging when full charge has been reached. 6) Watch for white flaky corrosion deposits on the upper edge of the cell near the pressure vent this can mean impending cell failure and electrolyte loss. 7) Dispose of permanently defective nicads properly - contact the manufacturer for instructions since cadmium is a dangerous toxic metal and has been banned from many dump sites. Try calling your local city hall and ask who can answer a question about cadmium metal waste disposal. 8) When the nicad battery power begins to drop near the end of a discharge cycle it will drop VERY QUICKLY due to the rapid characteristic dropoff of nicads. Prepare for laptop shutdown quickly. 9) Cycle your nicads through a FULL DEEP discharge and FULL COMPLETE recharge frequently - they will last LONGER before you must dispose of them and deliver MORE power when used. 10) Infrequently used nicads should be charged and discharged at least once or twice every two or three months to prolong their usable lifetime before permanent failure. 11) If your nicads are stated by the manufacturer to be quick charge type, you can probably prolong their life by slow or trickle charging them (if your charger provides that option) since you will minimize heat and gas buildup within the cell. Just because they can be quick charged does not mean they MUST be quick charged. Nicads last longer and deliver more power when not driven to extremes of temperature or overcharging. Tutorial finished. Be sure to order your FOUR BONUS DISKS which expand this software package with vital tools, updates and additional tutorial material for laptop users! Send $20.00 to Seattle Scientific Photography, Department LAP, PO Box 1506, Mercer Island, WA 98040. Bonus disks shipped promptly! Some portions of this software package use sections from the larger PC-Learn tutorial system which you will also receive with your order. Modifications, custom program versions, site and LAN licenses of this package for business or corporate use are possible, contact the author. This software is shareware - an honor system which means TRY BEFORE YOU BUY. Press escape key to return to menu. PURCHASING A LAPTOP COMPUTER ---------------------------------------------------------------- There is an allure to purchasing a laptop computer. They are small, sleek and highly productive. What features should you consider when purchasing a laptop? For those who need quick highlights first we'll present a brief overview for the cautious laptop buyer. Later in this tutorial we'll shift gears for a broader "beginners" overview. Before jumping into our tutorial, a reading recommendation. Visit your local library and locate a back issue of the August 1992 edition of PC Magazine. That issue covered a variety of reviews concerning specific laptop machines and also contained some surprising suggestions for productive laptop use. While on the topic of pertinent reading, check for other useful titles in the reading list section elsewhere within this tutorial. Next, general suggestions for laptop buyers... 1) The keyboard is the most important interactive part of any laptop. Is it awkward? Could you use it for longer than 15 minutes? An hour? A complete morning at work? Note the location of frequently used keys like the backslash \, the F1 function help key, the cursor control keys. Some oddball laptops require you to use a shift-funtion key combination for cursor keys. Not terribly comfortable. Othertimes the cursor position keys are oddly laid out in a non standard pattern which is difficult to use and memorize. One of the classic keyboard layouts is the Toshiba 286 T1200XE. Glance at the layout on this machine and compare it to your target laptop. 2) The screen. Next to the keyboard this is the greatest delight - or pain - when it comes to using a laptop computer. Can you use it for longer than an hour? Screens can be either backlit or edgelit. Each has advantages. Try both and see which you like. A few clever laptops have screen reversing software built in which can change the screen from black lettering on a light field to light lettering on a dark field. Helpful for some folks. Ask if your target machine has it. Find out if you like it. Is the output VGA (display and run most software) or lowly CGA (run and display fewer packages?) Is there a port on the back so you can plug in your big monitor to the back of the laptop when you are home or at the office? Do you need to buy an adapter for this? On an airplane tray can the screen be tilted so that the seat in front does not bump into the screen edge? 3) Weight. Fully outfitted with adapters, disks and batteries, what is the real "workday" weight of the laptop? Load the machine and accessories into a carrying case and heft it for a while. Brochures proclaim extremely light weight figures - in real life you will carry the computer and accessories. 4) Price. Determine the REAL price. You will need an AC adapater, carrying case and probably spare battery as a minimum. You will need DOS and some software. Beyond that, most people need a few manufacturer specific cables and sometimes a modem. Add it ALL up. 5) Battery life is a touchy subject - ultimately the attraction of laptops is the opportunity to get work done on the road. Battery life of an hour or so isn't much real work, when you think about it. Two to four hours on a fully charged battery is a working range today. Ask if the laptop has special battery saving features such as sleep mode, pause and resume, user selectable delays for drive and screen refresh use, powerdown mode, capability to change batteries without shutting down the machine and loosing data. Nice features. Is it easy and FAST to change batteries or a real chore? Look at the clasps and snaps as you open and close the battery compartment. 6) Modems. Someday you will need one. Does the laptop have a standard serial modem slot to which any low priced modem can be attached or a proprietary manufacturer specific slot to which ONLY that manufacturer's (expensive) modem will attach? For a few extra dollars consider a modem with combined internal fax send and receive capability which is a godsend for travellers. Much cheaper in the long run than paying your hotel $6 per page to transmit and receive faxes. 7) How much memory can you add to the laptop? For light word processing and spreadsheet work 640K may be all you need. But serious software use, Windows use or high end graphics may require 2 or more Megabytes of memory. How much can you install into the machine? How much will it cost? Can you install the additional memory or must the factory? 8) Drives. A standard 3.5 inch floppy drive is almost essential today. A hard drive, too, if you can afford it. If the laptop has no floppy, you might need to purchase special software and cables to transfer files between your laptop and desktop computer. One more expense. Back to the hard drive for a moment: if you work with large mailing lists, huge databases of clients or unusually large spreadsheets you MUST have a hard drive with larger than average capacity. Between 40MB to 100MB would be a wise investment for hard drive intensive storage applications. 9) Details. Beyond a serial port (for the modem or mouse) does it have a parallel port for a printer? How about capability for an external keyboard? Slot for math coprocessor? Null modem cable for transferring data between other computers. 10) Form follows function. If you plan to use the laptop mostly as your PRIMARY machine at home and work, focus on maximum power and expandable features. If you are a power user of Windows and graphics software you will need VGA display, at least 2MD of ram and at least a 386SX processor. However, if your primary work is spent on the road in planes and trains, pay attention to long battery life and quickly interchangeable battery packs. 11) Consider the new breed of tiny portable printers which work well with laptops. Included are the Diconix 150 Plus which weighs in at 3 pounds, Canon BJ-10 Bubblejet, Citizen PN48 and Star Micronics StarJet SJ-48. All printers will need spare ink cartridges, printer cable, paper, AC power supply and spare batteries. A brief glance at portable computer configurations.... Laptops are for the most part single-piece computer systems weighing in at between 7 to 15 pounds. In most cases the viewing screen opens in a characteristic "clamshell" manner. All are IBM compatible and most will functions from AC or battery power. Most offer some expanability in memory and some, but not all will even accept an expansion board. The latest designs can mater to a "docking module" which adds powerful desktop features when the units are used in a stationary office setting. Prices range from about $700 to well over $5,000 for advanced models. Examples: the Toshiba T4400SX, Librex M386SL, Bondwell B-310SX, Dell 320LT. Notebooks weigh in at 4 to 7 pounds and usually feature both AC and battery power. Both hard drive and floppy drive models are available. Prices range from $700 to about $2,000. By far notebooks are the most popular category in the consumer marketplace and for most users have the best balance of weight, cost and features. Examples: Epson NB3, Dell NX-20, Tandy 1800 HD, Sharp 6220, Tandy 110 HD, NEC 286F UltraLite, Compaq LTE286, Toshiba T1200XE. Palmtops. The smallest of the small. Weighing in at a pound or less these machines features minaturized keyboards, vestpocket size, lack of hard or floppy drives and varying amounts of true IBM compatability. Features are sacrificed in the quest for miniaturization. Some, such as the Hewlett-Packard 95LX contain built in software such as the standard Lotus 1-2-3 spreadsheet. At this writing, only the diminuitive Poqet palmtop is equipped to run most IBM compatable software. Tiny credit card sized memory modules are available for some models. Prices range from aobut $400 to over $2,000. Next, a broader tutorial about buying a computer for the first time. A refresher course for the advanced. An eye opener for the beginner. Some topic areas also address concerns about larger desktop computers as well as smaller laptops - a broad base of information is usually useful so references to desktop computers has been included. Buying a new or used computer is always THE traumatic event. It seems to be easier if you merely NEED one for a definite office or productivity goal such as financial analysis or compiling a mailing list of customers. In that case, you can be logical and evaluate among several machines and take your time. If, however you WANT one because it sounds interesting and you feel a little lost when everyone in the neighborhood is discussing CPU WAIT STATES, you have some serious research ahead! From a use standpoint, start at the beginning: What do you want to do with the computer? What software applications will perform these tasks? After determining answers to those two questions, purchase as much computing power as you can afford which allows you to use all current software of interest as well as retaining the possibility of upgrading the machine later - more memory or a better video display, for example. Simple applications like word processing, accounting and telecommunications may run equally fast on both budget and high end computers while sophisticated software such as drafting, large databases and desktop publishing may run so slowly on a low end computer that your wasted time far offsets the original savings on the budget computer. When in doubt run several software packages which provide features you want on the computer in question. Three technical factors are of interest when purchasing a computer: the type of CPU (central processing unit) which is the brains of a personal computer, the speed of the CPU and finally the choice between 8 bit and 16 bit CPU types. A brief refresher course: A bit is a binary digit used by computers to store and process data. Typically 8 bits are needed to construct a byte or computer character such as a number or letter. Eight bit processors can process one byte or character at a time. Sixteen bit processors can processor two bytes at a time. Faster is better for most folks - although speed has its price... In the IBM world of clone PC's there are four camps of CPU desire and capability. On the low end of price and performance are personal computers of the so-called XT class using the oldest processors such as the Intel 8088 (8 bit data bus outside the CPU and 16 bit data bus inside the CPU) which was used on the original IBM PC. The Intel 8086 CPU, alternatively, provides both 16 bit internal and external construction. A similar CPU is the NEC V-20 chip. Advantages, disadvantages and uses for these XT class machines? XT's are affordable. A basic machine with a couple of floppy drives, monitor and keyboard can be obtained for $300 to $400. XT class machines are useful for small and home office work or light hobbyist use such as word processing and accounting where speed is not of great concern. Generally XT class machines, as with all IBM clones, can be upgraded by the gradual (or immediate) addition of hard drives, color monitors and even faster processors. As a curious aside, this software package was programmed and edited entirely on an XT class machine. In a sense computing power does not derive from the machine, but HOW you use it! When is an XT not a good buy? If you intend to do CAD drafting, work with large database mailing list, or high resolution graphics, an XT is not a wise choice. If you ever to run the OS/2 operating system or Microsoft Windows which are advanced operating and display standards, XT machines are not a good idea. Finally, if you intend to expand the machine to color graphics such as an EGA or VGA standard or install large amounts of memory an XT is probably not an ideal choice. One step up the ladder in performance and price is the AT class machine which runs an Intel (or alternate manufacturer) 80286 CPU chip. The machine is usually 2 to 4 times faster than an XT class machine at perhaps $200 more in price. For most people an AT class machine is a comfortable choice since it can not only run OS/2 and Windows (albeit sluggishly) but also run earlier software programs at greater speeds. AT class machines are considered a "plain vanilla" standard in most office environments and are usually sold with hard drives and additional memory as standard equipment. The 80286 processor also operates in two modes which the 8088 and 8086 cannot: REAL MODE which allows the 80286 CPU to work like an 8088 CPU and PROTECTED MODE which allows access to more RAM memory. In theory, the older 8088 CPU chip can address up to 1 Megabyte of memory. An 8088 CPU always operates in real mode. In protected mode, however, the 80286 CPU can use up to 16 Megabytes of memory which can be an advantage in running both larger, more sophisticated programs as well as earlier programs. In addition, the 80286 CPU can, with the proper software, run several programs simultaneously which is know as MULTITASKING. The benefits of both protected mode and multitasking are somewhat unrealized at present although certain of these benefits can be obtained when running Windows software rather than DOS. Because of this, most users who continue to run DOS use an 80286 computer as a FAST device rather than seeking the advantages of multitasking or protected mode operation. And the 80286 is VERY fast indeed with some manufacturers pushing the CPU to speeds of 25 Mhz. Generally, adding additional upgrade equipment such as EGA monitors and laser printers is a good investment with an AT machine but a poor idea with an XT machine. The AT machine uses a 16 bit bus structure for rapid data flow while the older XT class machine uses a more primitive 8 bit bus. AT class machines run graphics and CAD programs relatively quickly. Hard drives operate quickly on an AT class machine with its larger 16 bit bus. It is a good choice for the small home office doing word processing, accounting, light desktop publishing, medium sized database mailing lists and so forth. Still higher up the food chain are 80386 and 80386SX CPU equipped machines which are still faster and provide a few more whistles and bells. They can run software which XT and AT class machines run, only FASTER. They are the machines of choice for office LAN networks, intensive graphics, CAD programming, Windows, OS/2, compilers and other number intensive programs. Curiously, though, the 80386 data bus remains 16 bits wide in most of these machines and there is no "OS/3" operating system, so the performance you derive is speed without additional whistles and bells. For most users, a "386" machine is mostly an office computer which a home or hobby user might admire but rarely need. Intel corrected the problem of switching from real mode to protected mode - a design flaw of the 80286 - and added a third mode called virtual mode which allows the CPU to act as if several "separate" 8088 computers are all running within one machine. In addition the 80386 chip is a true 32 bit CPU which processes four bytes or characters at a time. This 32 bit structure effectively makes the 80386 CPU twice as fast as the 80286 CPU. Finally, the 80386 can directly address a whopping four gigabytes of memory if available which is 256 times larger than the amount of memory the 80286 can address! The downside is that many of these advantages cannot be realized when running DOS. Windows or OS/2 operating systems provide access to these advanced features. Speed and additional memory capability is the primary byproduct of operating an 80386 within a DOS environment. The 80386SX is an affordable variant of the 80386 CPU. The key difference is that it uses an EXTERNAL 16 bit data bus outside the CPU which is similar to that used on conventional 80286 or AT class computers. Internally it is quite similar to its big brother, the 80386, and offers similar multitasking modes and memory addressing. It can run all of the software the 80386 machine can, albeit slightly more slowly. These design compromises allow manufacturers to produce an affordable computer with a good balance of speed and cost. For many users needing a powerful computer which can run all current and most future software, the 80386SX is an enviable balance of performance versus price and offers superior memory management, optimum speed and ability to run current and future software. The primary reason to select a 80386 over the 80386SX involves the need for higher speed processing, ability to run 32-bit software and advanced multitasking. Before introducing the fourth Intel CPU, the 80486, two new concepts must be mentioned: memory caching and mathcoprocessing. As the speed of the CPU becomes faster, the RAM memory chips where data is stored have difficulty moving data into and out of the CPU. Memory caching involves special high speed RAM memory chips - typically an amount from 64K to 128K - in addition to the normal memory chips within the computer. These high speed chips are expensive but keep data poised to quickly move in and out of the CPU. Memory caching should not be confused with disk caching which is another concept used when discussing hard drives. A second way to increase performance is to install a math coprocessor chip into the empty socket which is available on most computers. This device shares the processing of specific numeric operations which can slow the CPU. Only certain types of software support math coprocessors such as some CAD, spreadsheet and graphics software. Not all software benefits from the use of a math coprocessor. The 80486 CPU combines the features of the 80386 chip plus the addition of a self-contained on-chip coprocessor and memory cache. Although the memory cache is small, a mere 8K, it is extremely effective since it is onboard with the CPU itself. The 80486 is useful for advanced scientific applications, CAD drafting, graphics and high speed LAN (local area network) shared computers in an office environment. An 80486SX CPU is also available which is essentially a "poor man's" 80486 with a smaller external data bus. Back to CPU clock speed. Older XT (8088 CPU) machines operate at a relatively slow speed of 4.7 to 10.0 Mhz or Megahertz. One Megahertz equals one million cycles of electricity per second. AT class machines (80286 CPU) operate in regions of 10 to 25 Mhz while 80386 and 80486 machines operate at speeds in the 20 to 40Mhz region. Obviously faster is better especially when it comes to colorful graphics displays, CAD drafting, large spreadsheets and massive programming tasks. However simple word processing, small business accounting and routine mailing list management is more than adequate at 4.7 Mhz. The need for speed is relative to the computing task at hand! Let's backtrack for a moment and discuss RAM memory. Most computers are sold with a specific amount of memory installed on the main "motherboard". Increments of 640K to 1Meg of memory are common. It is commonly advertised that additional memory may be added as "expandable on the motherboard" to some upper limit such as 4Meg or 8Meg. Thus the user can easily install plug in chips of SIMM's (single inline memory modules) to sockets on the motherboard. If possible, insist on SIMM memory modules which are simpler for the average user to install rather than earlier DRAM chips. Additional plug in memory boards can also be installed into computers having an 80286 or higher CPU. Up to 16 Meg of RAM memory is possible on 80286 CPU equipped computers. Why install more memory beyond the 640K which DOS can address? For fast memory caching, RAM disks, TSR installations, access to programs which can use either or both expanded or extended memory, to run the Windows operating system or OS/2. These software requirements are not terribly exotic - but are simply ways to improve performance and speed for more experienced computer users. The hard disk is also a consideration in any computer purchase. CPU speed is determined by the clock speed of the computer while hard drive speed is determined by two factors: access speed and drive type. Extremely fast hard drives operate at 18 milliseconds access time or faster. Bargain computer hard drives operates in the range of 28 to 40 milliseconds. Hard drives must also be mated to a controller circuit which offers its own blend of performance and economy. MFM and RLL drive/controller combinations are earlier and less expensive hard drives while ESDI, IDE and SCSI drives are faster and more expensive high performance options. Floppy drives come is various configurations. Budget computers may contain only a 1.2MB floppy drive and hard drive. This configuration can read two floppy densities: 1.2MB and 360K floppies. A more flexible computer contains a hard drive, 1.2MB floppy and 1.44MB floppy. This computer can read four floppy formats: 1.2MM, 1.44MB, 720K and 360K. Ask if a budget computer can later be upgraded to include other drive configurations. The new smaller drives housing the rigid "mini floppies" such as the 1.44MB and 720K formats hold 20% to 50% more data in a sturdy plastic case with spring loaded dust door. Monochrome displays are suitable for low end word processing but today's software usually requires VGA color resolution as a minimum. An affordable option is a VGA video card and a MONOCHROME (black and white) VGA monitor which provides an acceptable 64 shades of gray with most modern software applications. Several sources of computer equipment are available - each with a different flavor. 1) Manufacturer direct or direct sales, such as Dell, Northgate and Zeos. This method usually assures relatively high quality at fairly attractive price savings since you are dealing directly with those who design and manufacture the computer. Service is usually good, via telephone, FAX and BBS. The downside is that you must deal through the mail and await delivery. Price is very attractive, but not necessarily the lowest available. 2) Retail vendors such as Computerland or Tandy. Convenience is the factor here since service, returns and delivery is handled locally. You pay slightly higher for this additional convenience. Generally this is the most expensive computer purchase option. 3) Mail Order Houses. Almost 15 percent of PC sales are conducted by mail. Mail order houses do not completely design and build their own systems like direct sellers but rely on imported and pre-manufactured assemblies. Technical phone support can be variable, but if you shop carefully, you can save even more over local retail or manufacturer direct channels. Mail order sources are available in newsstand magazines such as Computer Shopper and PC Sources. 4) VAR's or Resellers. These specialized vendors usually provide systems in volume frequently with "value added" features such as special software setup, training or unique customization of computer systems. 5) Home brewers. The ready availability of computer components has spawned a cottage industry of small shops, some in home or low rent office spaces which can custom design a system or allow you to build your own computer using parts and facilities which they provide. These small, minimum overhead operations can provide extremely low prices but guarantees and service contracts should be provided in writing and background of the vendor should be investigated carefully. What are some questions and requirements in purchasing a system? What speeds are available on the CPU? 10 Mhz is standard on XT's with 12 to 20 Mhz on AT's and 33 mhz on 80386 machines. How many free slots are available on the internal motherboard for expansion with future upgrade circuits? Five to eight expansion slots is desirable except on small laptop computers. Is there both a serial and parallel port? How many of each? Mouse port? Is a clock chip included? How big is the hard drive? 40 to 80 Meg is considered somewhat standard in size today for most hard drives although smaller 20 meg hard drives are useful for light office use computers. How many bays are available for extra drives? Two is minimum. How many floppies? What size of floppies? Most computers today minimally have either two floppies OR one floppy and one hard drive. Who makes the hard drive? Seagate, Connor and Miniscribe are considered reasonable, although not exclusive choices. Who makes the floppy drive? Teac, Panasonic, Sony and Toshiba are considered reputable in floppy manufacture. Whose BIOS chip powers the machine? Phoenix, Award and AMI Bios chips are all fine. How much memory is installed on the motherboard. 640K is a bare minimum for all machines with 80286 and 80386 machines usually offered with at least two to four Megs of RAM memory. Any memory cache chips? Any coprocessor installed? Coprocessor socket available? What warranty covers the product and for how long? Does the warranty cover both parts and labor? Does the vendor have sufficient inventory to replace the entire computer if problems arise? Is there a different warranty for the printer? Who provides the service? What is the vendor's return policy AND refund policy. Is there a restocking charge? Is there a discount or change in price when dealing by check or charge card? How long has the vendor been in business? Is the warranty 90 days, one year or two years as some manufacturers are now offering? Money back guarantee? How long? 30, 60, 90 days? What type of refund on this guarantee: store credit, cash, exchange? Will you put it in writing? Shipping and handling fee? Visa card surcharge? How good is technical support? Is there a toll-free support line? 24 hours or limited hours? Is there a BBS (modem) telephone line for support? Is maintenance performed on site (the customer's location) or only at the vendor's location? Response time? Special conditions? Is the on-site service essentially the same in terms, such as parts and labor, as off-site? Has the vendor sold computers to buyers in your business specialty (medical, for example). References? How long has the vendor been in business? What is the estimated life of the PC? Of the hard drive? How far can it be upgraded? In RAM memory? How many expansion slots? Can the CPU be upgraded? The display and graphics card? What is the MTBF or mean time between failure of the components such as the hard drive and printer according to printed manufacturer's literature? Does the computer come with ALL the parts you will need such as monitor and graphics card? On many bare bones systems this is extra. Are the accessories from the same manufacturer? Is the item available for immediate shipment or is a backorder the option of the moment? When will it be shipped? Has there been a recent price increase? Any financing options available from the vendor which offer advantage over bank or credit card purchase? Leasing options? Bank financing carried by the vendor? What bank? Extras included with purchase? Documentation? DOS software? What version? DOS 5.0 is the latest. Mouse? Software installed on the hard drive? Is it legal software? Is is commercial software? Shareware? Any training classes provided? When? How often. Brush up training free? What utilities and extra software comes with the machine? Any hard drive menu systems or utility software? How is the documentation? Really good or just whatever the manufacturer had translated? What display monitor and card are included (if any)? VGA is standard. EGA is minimum. CGA and Hercules are the bare minimum. Are printer cables included with purchase of the printer? Any spare printer ink cartridges included? How is the keyboard. Springy and clicky with a tactile feel or just mushy and so so? Is the Basic programming language included or is this an extra cost. Will the manufacturer throw in a software package suitable for beginners such as Microsoft Works? Is the machine FCC class B certified (the best) or class A (acceptable)? What is the interleave on the hard drive (1:1 is fastest)? Is the keyboard an 84 key type or 101 key type? Is the computer case metal or plastic? How hard or easy is it to pop the cover and install new circuit cards? Does the keyboard plug into the front or back of the machine? The front plug option is a sometimes more handy. Is the reset and on/off switch on the front, back or side of the machine? Front is again more handy. Panel lights on the machine to indicate CPU speed and hard drive use? Keylock for security? How many copies of the key? Does your key fit all the computers in the store too? Does a local computer club/user group buy from the vendor which might provide personal references who can discuss why they bought from that vendor? For those who wish to read published reviews concerning specific brands of computers, printers, monitors, modems and software: the most complete resource is PC Magazine published by Ziff- Davis and available at most libraries and many newsstands. PC Magazine editors usually select one or two items within a product classification as their "Editors Choice." The complete index to both PC Magazine as well as their product review index is contained in their on-line modem service PC MagNet. Instructions for reaching PC Magnet by modem are contained in the Utilities section included within each issue of PC Magazine. For product reviews of hardware and software you may wish to download the PC MagNet files PCM.EXE, PCSRCH.EXE and PCM.INF which are quite large. The files occupy more than 2 Megabytes of disk space and require about 1.5 hours of somewhat expensive modem connect time. Alternatively, you can reach the same index of products on line within PC MagNet by typing GO REVIEWS which allows you to search the product review database directly. A larger database of 130 periodicals and their respective product reviews can be viewed by typing GO COMPLIB from within PC MagNet. Additional product review sources are suggested on page 27 of the June 26, 1990 issue of PC Magazine (Vol 9 No 12.) Page 397 of the same issue contains instructions on reaching and using PC MagNet by modem. If you do not have a modem or a friend with that capability, a low-tech method for reviewing specific computer hardware and software recommendations is to visit a local library which contains back issues of PC Magazine. Glance at the magazine cover for highlights of products reviewed in that issue. If you work your way from the current issue backwards in time for 6 to 12 months, you should find detailed reviews on the equipment you are investigating. Many computer clubs maintain a library of PC Magazine issues and may be a source if your local library does not subscribe to the magazine. Yet another way to constructively shop for computer equipment is to obtain free catalogs which are provided at no charge by reputable computer vendors and manufacturers. See the listing of free equipment catalogs contained in the recommended reading/bibliography section elsewhere on this disk. ---------------------------------------------------------------- 22 BASIC COMMANDMANTS OF COMPUTER CONSUMERISM ---------------------------------------------------------------- 1) Does the computer contain sufficient RAM memory and CPU speed for the applications you intend to run and how easy is it to add more memory? A 80286 computer may be fine for word processing, for example, but a poor choice for extensive desktop publishing. 2) Is the computer FCC approved with an FCC sticker? Class A or B? Class B is better since it means certified for home use and theoretically emits less objectionable static radiation. 3) Have you identified the software you will (or might) be using? Can the machine run that software? Is DOS included with your machine? 4) As your needs change in time, will the machine expand or change with those needs? 5) Is the outer case of the computer large enough to accommodate additional expansion circuit boards? How many? 6) Is the power supply sufficiently large for future expansion? What is the wattage of the power supply? Is the fan noise low or NERVE WRACKING? 7) How many and what kind of floppy drives do you need? 8) Is the hard disk (if the machine contains one) certified for use with the internal controller board which operates it? What make on the controller card and hard drive? 9) Is the hard disk set with the correct interleave factor? 10) Will your dealer offer superior service after the sale? Who does the service? Where? Any free training classes? 11) Are all warranties in writing and how do they compare to other dealers warranties in writing? 12) What kind of monitor will you need and does the video adapter card inside the computer allow for monitor upgrades and will it display the software you intend to use? 13) Are you buying the computer or a sales pitch? 14) Are the internal components industry standard? Especially the floppy and hard drives. What brands? 15) Is the dealer trying to sell you more/less than you need? 16) Have you set a realistic budget? 17) Have you gathered information for all sources such as friends, magazine reviews, stores and advertisements? Are you relying on one computer guru from work or, more wisely, several? 18) If the price is far below the average, something is missing. What is it? Quality of the hard drive, lack of higher resolution video, toll free telephone support, software such as DOS? 19) Determine the REAL price by extracting hidden additional shipping charges, credit card surcharges, restocking charge if item returned. 20) Pay by credit card if possible since if you end in dispute, your credit card company can go to bat for you and issue a credit until the dispute is resolved. In addition, many credit cards automatically double the manufacturer's warranty. 21) Get details in writing. What is the salesperson's name? What is the exact shipping date? 24 hours? same day? Get it in writing via FAX. Retain the ORIGINAL AD which promoted the computer. A paper trail established early is the best protection. Retain warranty cards long enough to test all equipment functions first! If you mail in manufacturer's warranty cards too quickly, you may have to settle for warranty coverage rather than replacement by the vendor. 22) Retain all original cartons and packing material. Many vendors ABSOLUTELY require it in case of return! ---------------------------------------------------------------- MUSCLE FOR COMPUTER CONSUMERS - THE LONG ARM OF THE LAW ---------------------------------------------------------------- If you are dealing with a mail order supplier, Federal Trade Commission rules apply! Essentially the vendor must ship the order within 30 days of receiving it unless the advertisement states otherwise. If a delay will be experienced in shipment, the vendor must notify you in writing of a definite new shipment date and also offer you the chance to cancel the order with full refund. That notice must include a stamped or self-addressed envelope or card which allows you to indicate your choice. If you do not respond, the seller may rightfully assume you accept the delay. However, the vendor must either ship or cancel the original order within 30 days after the original shipping date which was promised. Any refunds for order cancellation must be made promptly. Even if you accept an indefinite delay, you have the right to cancel the original order at any time before the item is shipped. If you chose to cancel any order, which has been paid by check or money order, the vendor must mail a refund within seven business days excluding weekends and holidays. Likewise if the order was paid for by credit card, the vendor must credit your account within one business cycle following your cancellation request. Store credits and other methods or offers of similar merchandise are NOT acceptable unless you agree. If the original item is not available, a substitute item, even if similar, is not acceptable unless the vendor has your consent. Report violations to the Federal Trade Commission whose phone number is usually listed in the blue pages (government section) of your local telephone book. Tell the vendor you are reporting violations to the FTC and mail the vendor a copy of the letter you wrote to the FTC. This usually brings action quickly. One primary conduit for recourse is the Direct Marketing Association which maintains an action line for problem resolution. First you should attempt to deal directly with the seller, but if a problem is not promptly resolved you may wish to contact the Mail Order Action Line, c/o DMA, 6 East 43rd Street, NY, NY 10017. The first step in any attempt to seek redress from a vendor is to notify the supplier in writing that the item is defective and include a copy of the invoice with information as to model, price, date of order and account number if available. Retain a copy of your letter seeking refund or replacement. Any phone calls should be followed by a letter. Generally do not return the item to the vendor until told how and when to do so, since many have formal return policies and require "return authorization numbers" which are usually issued to you by phone or in writing. The return authorization number accompanies the defective item on its return. Keep a copy of the shipping receipt and packing slip. Any rights to recover postal or shipping costs is determined by the policy of that vendor as is usually stated in advertising and product literature. You may also consider contacting the attorney general for the state in which you live as well as the state in which the vendor does business. This can be MOST effective especially if you send a copy of that letter to the vendor. If the product was paid for with a credit card, you may also retain the right to withhold payment or cancel payment which is usually arranged directly with your bank or credit card issuing agency. This is explained under provisions of the Federal Fair Credit Billing Act. Tutorial finished. Be sure to order your FOUR BONUS DISKS which expand this software package with vital tools, updates and additional tutorial material for laptop users! Send $20.00 to Seattle Scientific Photography, Department LAP, PO Box 1506, Mercer Island, WA 98040. Bonus disks shipped promptly! Some portions of this software package use sections from the larger PC-Learn tutorial system which you will also receive with your order. Modifications, custom program versions, site and LAN licenses of this package for business or corporate use are possible, contact the author. This software is shareware - an honor system which means TRY BEFORE YOU BUY. Press escape key to return to menu. COMPUTING TIPS, TRICKS AND TRAPS PLUS COMMENTS REGARDING ENVIRONMENTALLY SAFE COMPUTING ---------------------------------------------------------------- Sometimes it takes months or years to stumble onto the ESSENTIAL tips, tricks and traps with which every PC user should become acquainted. Let's discuss a few of the more important items which never seem to be covered adequately in the instruction book which arrives with the computer. Many of these tips apply to both laptops and desktop computers. If you are an advanced user, glance at all of the tips - this tutorial contains a sprinkling of basic, intermediate and advanced tips. A little something for everyone! Let's begin.... Don't experiment with ORIGINAL copies of your files! If you want to tinker with a word processing file or slice and dice your accounting data FIRST make a floppy or hard disk copy of the file and then work on the COPY in case something goes wrong. That way you will have the original to fall back on in case you need it. Don't buy floppy disks when the price is too good to believe. If your data is worth anything at all, a few pennies more can make the difference between having that important business letter obtainable or a dreaded error message on the screen that your file format is unreadable just when you needed that file at 3 AM. Make backup copies of important files. If the data is REALLY important, keep yet a second or third copy in a safe deposit box in case your home or office burns down! Sounds a little severe, but just wait until you discover the joy of doing your income tax return on your PC (fantastic compared to the old pen and pencil way) and then discover somehow the ONLY copy of the file is no good when the IRS decides to perform a routine audit! For backup you might want to switch from the COPY command to the sensational DOS XCOPY command (available in DOS versions 3.2 and later) which also allows file copying and backup using additional parameter switches which you can read about in your DOS manual. For example the /S switch used with XCOPY will copy all files from your subdirectories to the new target disk. Adding /P to XCOPY will cause a pause at each step to ask whether you want each file copied. Using the /D switch followed by a date will allow you to copy only those files created or modified on that date or later. All three of these switches can be used in tandem. Here's a standard tip which is so simple most people overlook it. Whenever you buy a box of new diskettes, FORMAT them immediately. Why? Reason one: you will find out if any disks are bad and be able to return to the store rather than be down to your last (surprise: defective!) disk when you need it. Reason two: usually you are right in the middle of a long word processed document and need to save the file, but OOPS, your current disk is full. No problem. Just reach into the desk drawer and grab an empty floppy disk. SURPRISE! The floppy disk is NOT FORMATTED which forces you to exit your word processor, lose the data permanently from RAM memory, and format the disk just as you should have in the first place. Beginners luck, I guess. . . Here's an extremely important tip most beginners should consider: AT class computers and those containing a 80286 CPU chip also contain a special battery to maintain the "setup configuration." This battery will eventually die and thus cause you to lose your important setup data. The first sign that your battery is going are mysterious losses of time and dates. Other "strange" data losses may start to occur. Eventually your computer will even refuse to start! Preventative maintenance suggests that you dig around on your DOS disk(s) and locate the SETUP program. Run setup and when you see the configuration report screen (lots of funny numbers and settings), hit the SHIFT-PRTSC (Shift key and Print Screen key pressed at the same time). This will force a printout of the valuable setup data to paper. You can also obtain shareware and commercial software programs that will store this data to disk. Most experienced users deal with the situation by making a copy of this setup data onto a "safety disk." If your battery dies, you will be able to quickly reconstruct the setup data from your paper sheet or safety disk after replacing the battery and running the setup program (or safety disk backup program.) A better method, of course, is to realize that the battery contained inside the computer lasts for about 2 to 4 years and simply keep a record (much like oil changes on your car) and manually replace it well before the deadline. Of course when you replace it, run the setup program and record the setup data on paper, since once you remove the battery the data will be lost from memory. You might investigate newer battery systems which automatically recharge themselves from the power source of the computer and thus never need replacement. IBM originally designed this feature, by the way, to supplant the older "dip switch system" on the first PC's. In older computers of the XT design, a user had to remove the PC cover and carefully set tiny switches deep inside the computer whenever a different circuit board or monitor system was used. This was tedious, so the software equivalent of the tiny switches were created in memory with settings stored by battery (when the computer was shut down). This allowed users to change the setup from the keyboard using the DOS setup program from the DOS disk rather than removing the cover and fiddling with switches. The downside is that now we must replace the battery periodically and of course record the setup data on paper or disk. Technology marches on! Here's an "insider's" tip power users are familiar with. When working with long text or document files such as instructions for shareware packages, business letters and other text files it is frequently useful to extract small portions to a separate file or print for future reference. Power users frequently use the shareware program LIST which browses or displays these documents and can "clip" screens using the frequently overlooked ALT-O key (press and hold ALT then hit O). Assuming LIST is currently browsing your document, it will ask for the name of a file to create which you may supply (e.g., custom.doc). List will extract that single screen of data to the file. As you continue browsing the document, hitting ALT-O will append or add any additional screens to the special target file! When finished you have a compact file of extracted text data which you can save, print or edit with your word processor rather than wading through endless screens of the lengthy master document! LIST is available from all shareware vendors, many computer clubs and individual users. Several shareware vendors are listed in the tutorial on software. Want the ultimate simple database? Combine LIST with any simple word processor or text editor. Using your word processor type in any list of ideas, phone numbers, addresses, parts inventory which needs to be tracked. Save the information on disk as an ASCII (plain text) file. Load the file into LIST using the appropriate command (e.g., LIST INFO.DOC) and use the high speed search feature by pressing the F key (F for find) and enter a search phrase to locate (e.g., Denver). List will locate that phrase and the information near it very rapidly. Pressing the F3 key will take you to the NEXT occurrence of the same search phrase. When finished, hit the HOME key to return to the top of the document to begin a new search. Technically you could use your word processor's search feature to locate information also, but LIST is quicker and more flexible. To update your simple database, periodically edit the master document with your word processor to change, delete or update entries. When you turn on your computer each morning does DOS greet you with several prompts instead of one? Do you see: C> C> C> This is easy to fix since most beginners are unaware that someone has probably tinkered with the AUTOEXEC.BAT file and inadvertantly added a few extra carriage returns to the end of the file by pressing the return key several times when the file was orginally created and saved on disk. Simply load AUTOEXEC.BAT back into your word processor and remove all (usually invisible) lines and spaces and carriage returns at the end of the file (use the delete key). Resave the file as ASCII text with the same name and your problem should disappear. Beginners also need to know about the alternate keyboard. Sometimes you need a special symbol like the cents sign, the British currency (pounds sterling) symbol, or the one half fraction sign. IBM compatable computers contain an "alternate keyboard" system which allows access to special math, foreign language and graphics symbols. The source is a special ASCII chart printed in the appendix of your DOS manual as well as most computer reference books. It's easy to use this system: while you are in your word processor, DOS or other program, press AND CONTINUOUSLY HOLD DOWN the Alt key and then USING ONLY THE NUMBER KEYS ON THE NUMERIC KEYPAD (to the right of the keyboard, not the normal number keys above the keyboard) hit the three digit DECIMAL number code of the special character you need. For example, from the ASCII table in the back of my DOS manual I note that the symbol for the British currency Pound is decimal code 156. I hold down the Alt key, press in sequence the three numbers 156 on the numeric keypad and finally release the ALT key to get the proper symbol on my screen. There are many useful symbols for foreign languages, math, fractions, foreign currency, symbols to draw boxes, lines and useful graphics symbols. Note that these ASCII symbols will usually display properly on your screen but MIGHT NOT print properly on your printer since some are used for special control codes and other activities. Many will, however, display on both your screen and printer. Jot down the codes for the most interesting ASCII symbols to keep near your keyboard! By the way, PC-Magazine published a shareware utility called ASC.COM several years ago (available from many computer clubs and BBS systems) which can "pop up" over many of your programs and display the full ASCII code table for quick reference and handy use if you don't want to go searching for the ASCII index in the back of your DOS manual. Before leaving the discussion about the alternate keyboard, note that crucial control of your printer - setting various typefaces and features - can be provided via a combination of batch files and use of the alternate keyboard. See the printer discussion at the end of the batch file tutorial elsewhere on this disk. Absolutely lethal trick: If you get the message ABORT, RETRY IGNORE? from DOS while you are attempting to copy files from one drive or disk to another DO NOT EVER switch disks in the target drive (i.e., the drive to which files will be sent) then answer RETRY. If you do, you will end up with a hopelessly scrambled mess on the target disk if it already has important files in place. This can occur, for example, when you try to copy files to a disk which has a write protect tab in place. Your temptation might be to insert another different disk and retry. However, when DOS copies files, it first reads the directory of the target disk and stores it in memory. If you switch disks, the in-memory copy of the directory of the OLD disk will overwrite the directory of the new disk. Best situation in this case is to answer abort and rekey the operation again (shortcut with DOS is hit F3 to automatically reissue the last command) then try another disk, if necessary. There are other ways this dangerous situation might arise besides a write protect tab, so be careful. Don't install or change add-in circuit boards or cards within your computer with the power on. And be extremely careful about static electricity. Try to briefly touch a metal ground such as a lamp or metal window frame to discharge stray static electricity before you touch your fingers inside the PC. Static electricity discharges can blow out one or several integrated circuit chips and leave you with a repair bill of $300 or more! If you ever see the message: ARE YOU SURE (Y/N)? always answer no unless you really know what is going to happen next! This message usually precedes disaster as DOS prepares to delete all of the files on a floppy disk or format your hard drive and wipe out all data. Don't invite dumb power problems. You are typing the last draft of a valuable client contract and your 30 foot long power cord dangles in front of both family cats on its meandering way across the middle of the living room carpet to the wall socket. It is plugged into a rat's nest of four way plug adapters along with high-current drawing air conditioners and toaster ovens. This is a great way to send your data to toaster heaven while we are on the subject. Treat your hard drive with EXTREME tender loving care while it is spinning. No bumps, jolts, slams or ramma-lamma-ding-dongs! One little bump will send the read/write heads plowing into the spinning disk surface. Kind of like a 747 jet crash into the library of congress. Translation: large data catastrophe! If your data is sensitive and you lock the keyboard with that cute little key which slips into the front panel of your machine, DON'T forget to remove the mouse or other input devices. Since a mouse is an alternate input device, a savvy user can easily direct the computer to spill forth its information even while the keyboard is locked. Use the DOS command DISKCOPY in ONLY two cases: to make a backup copy of new commercial software OR when you have somehow damaged a disk and want to work on it with the Norton utilities or some other recovery program. For all other copies you are safer to use the COPY or XCOPY command. Reason? DISKCOPY does not remove file fragmentation which COPY does. Second reason? DISKCOPY can attempt to copy good information onto a target disk sector which has formatted bad or is otherwise unavailable to DOS. Use COPY *.* to copy all files on a disk and you will simultaneously copy everything and unfragment the files. Two operations for the price of one! Thunderstorm coming? Shut down the computer and unplug it from the wall INCLUDING the modem or telephone line! LIghtning hits to the power or phone line send very high voltages hurtling down the wire. If you prefer you can leave the computer plugged in and chose as to whether you wish your PC scrambled, sunnyside up or just deep fried! Never switch or remove disks in the middle of an aborted program operation. If for some reason you get an error message in the middle of a file copying session or disk writing operation, don't swap in another disk! DOS may think the old disk is still there and continue to write the remainder of the data over something valuable on the new disk! Better to stop what you are doing and issue a non-writing command such as VER or DIR or even shut down the computer in extreme situations rather than mangle two disks with misinformation. Be careful using the DOS commands ASSIGN, FORMAT and RECOVER. Especially if you are being a little too clever and change disk drive letters with the DOS commands ASSIGN, JOIN and SUBST. What happens is that you might temporarily rename your hard drive the B: drive and then absent-mindedly try to format B: or recover B: which will lead to a lot of deleted data on your hard drive. Generally the RECOVER command is best removed from your DOS subdirectory and never used. It is just too dangerous! If you delete some files by accident, Norton Utilities, PC Tools and several other utility programs can bring them back if you are quick to use them and haven't created or changed any files since the accident. Best to go out and get a copy of Norton, PC Tools or a shareware unerase utility (e.g., Bakers Dozen) before the need arises. Then practice using them on a dummy disk for the likely day you need them. Be careful when using the powerful DOS redirection and piping commands discussed in our earlier DOS tutorial. (example) a>sort < this.doc (sorts contents of this.doc on column one and displays contents on the monitor - a nice idea!) (example) a>sort > this.doc (trashes any existing this.doc and gives it a file length of zero! Bad news!) The same advice also applies to using the MORE command with redirection arrows < > since you can likewise wipe out data files. Watch the direction of those cute little redirection arrows! Same thing applies to using the redirection arrows when you write batch files. Look at the sample line from a batch file listing below: (example) ECHO -------->This message is important! In the above example, DOS will erroneously think the little > redirection symbol is telling it to create a file named THIS and use ECHO to redirect text from that line of the batch file into the file. A goofy, dangerous result! Another good boner is the following batch file example: (example) ECHO Now use the c>prompt to return to DOS The above perfectly innocent batch file line creates a file called PROMPT because DOS spots the > symbol and does what you told it to do! Instructions mean business! If program documentation says MUST BE USED ON A COLOR MONITOR don't try to run it on your hercules or monochrome system. Software can indeed destroy a monitor and it only takes a second! Know what your monitor and display card can handle and be SURE that the intended software matches hardware capabilities. If you suspect a business or individual may be illegally using a commercial software package, for example buying one copy and then installing MANY copies on various machines, you should report the violation to the Software Publishers Association. Call tollfree: 800/388-7478. SPA use of Federal and State law enforcement methods is sudden and highly visible. The SPA is quite aggressive on this point. The majority of calls received by the SPA are from "whistleblowing" employees within a business which is illegally using software. If you use a RAMDISK to hold data be sure to stop every half hour and copy the information into a more permanent floppy or hard disk area in case of power failures. In fact every half hour, check to see that your data from ANY program is transferred to magnetic disk. No exceptions! For those using the newer disks having 1.44 Meg and 720 K sizes - those little plastic diskettes - don't swap and mix formats willy nilly. Label the diskettes clearly and know the format density (1.44M or 720K) with which you are working. If data is sensitive and you want it GONE from snooping eyes, use a utility like Norton's WIPEFILE to truly delete it from the disk so an office curiosity seeker can't bring it back with an unerase utility! Likewise, some word processors create backup files having the extension BAK. You may think you have deleted that sensitive client proposal when a second document CLIENT.BAK also exists! DOS manuals make reference to the VERIFY command. You can add the /V switch to the COPY command to supposedly verify the accuracy of the second file copy. Likewise you can turn VERIFY ON and VERIFY OFF from within your AUTOEXEC.BAT file. Unfortunately, the VERIFY command does a rudimentary CRC check which can test only gross errors in file transfers. To be sure the second copy is good, use the COMP command which, although slow, is deadly reliable when you "gotta be sure." The FC command found in MSDOS versions is even better and DOS manuals discuss its use. Likewise use the DISKCOMP command whenever you use DISKCOPY if you absolutely have to be certain that the second diskette is PERFECTLY identical to the first. Our next tip concerns computing devices and services to assist the disabled: AbleData, Adaptive Equipment Dept, Newington Children's Hospital, 181 E Cedar St, Newington, CT 06111 800/344-5405 Accent on Information, POB 700, Bloomington, IL 61702 309/378-2961. Apple Computer, Office of Special Educ. and Rehab., 20525 Mariani Ave. MS 43F, Cupertino, CA 95014 408/996-1010 Closing the Gap, POB 68, Henderson, MN 56044 612/248-3294 Direct Link of the Disabled, POB 1036, Solvang, CA 93463 805/688-1603 Easter Seals Systems Office, 5120 S. Hyde Park Blvd, Chicago, IL 60615 312/667-8626 IBM National Support Center for People with disabilities, POB 2150, Atlanta, GA 30055 800/426-2133 Proceedings of Johns Hopkins National Search for Computing Applications to Assist Persons with Disabilities. IEEE Computer Society Press, 10662 Los Vaqueros Circle, POB 3014, Los Alamitos, CA 90720-1264 American Foundation for the Blind, 15 W. 16th St, NY, NY 10011 212/620-2000 Trace Research and Devmpmnt, Univ of Wisconson, Madison Room S- 151, Waisman Ctr, 1500 Highland Ave., Madison WI 53705 608/262-6966 National ALS Association, 21021 Ventura Blvd, Ste 321, Woodland Hills, CA 91364 818/340-7500 ---------------------------------------------------------------- ENVIRONMENTALLY SAFE COMPUTING ---------------------------------------------------------------- Computing has impacts on the earth and I would like to share a few constructive suggestions and tips about saving resources and protecting the environment. Computing uses paper. Keep two wastebaskets by your desk and recycle. Same for cardboard packing boxes and packing materials which arrive with computing equipment. But let's go a little deeper with the paper issue: Do you really need to print on multiple part carbonless forms and heavyweight computer paper?