memory is to buy a new system board altogether: a much more drastic and expensive solution than an expansion card, which simply plugs into the sys- tem board. Modems: All Alone, or the Telephone? Modems (short for modulator demodulator, phew!) are little paper- back-book-sized bundles of circuits that allow computers to "talk" to each other via telephone lines. With a modem, you can buy access to all the business, scientific, educational, and other data bases available out there; without it, you're computing in splen- did isolation-not all bad if all you need to do is revise that term paper and correct the spelling on your chem- istry homework: Still, attaching a mo- dem to your PC can cost as little as $100, and widen your academic and even social horizons considerably- after all, some data bases are dating services! Most modems require an RS-232C serial port; that is, a socket at the back of the system unit into which a stan- dard serial-type cable can be plugged. Be sure that your modem supports both the 300- and 1200-Baud data transmission rates. (A "Baud" re- flects the number of electronic im- pulses, or bits, that can be sent or re- ceived per second.) Be even more sure that your PC doesn't already have a modem built into it, since many do. "Smart" (read "expensive") mo- dems contain processors that can be instructed to perform preset, timed, dial and redial operations at low traf- fic hours, even when you're asleep. One Floppy Drive, or Two? Will your PC support the addition of a second floppy diskette drive? In other words, is there an available slot in your system unit, or an available port for attaching an external one? A second floppy diskette drive provides greater flexibility and increased stor- age for your own data. Personal Writers: The In-Between Machine Well, no, it's not exactly a type- writer (can your typewriter auto- matically count the - number of words you've written on any given 2500-word essay?), but it isn't ex- actly a PC either-do you know any computers with their printers built right in? Personal writers look like PCs and, as far as word processing goes, act like PCs-they're even con- trolled by semiconductor chips and utilize floppy disks that can store up to 140 pages of text-but they really aren't PCs. Introduced to the market more than a year ago, personal writers come complete with keyboards, video displays, spelling checkers, features that allow you to move, edit, and rearrange whole blocks of text at a time. They'll even print out endless numbers of copies of what- ever information they've been fed. What won't they do? Number crunching. Communi- cating with other computers. Pro- gramming. They can't prepare your income tax. They won't keep an in- ventory control of your loaned-out rock tapes. Still, they're easy to use. You don't need to learn anybody's spe- cial software commands to come up with a neatly organized, correctly spelled, tidy term paper (with an ex- tra copy to send home to Mom to show her how hard you're work- ing). Operating instructions are simple. You can even change type- faces if you want. It costs about the same as an ex- cellent electronic typewriter, per- haps less, as these in-between machines become more popular. There are 20- to 40-megabyte hard disks and "hard cards" that can be in- serted into the system unit, if space al- lows. (A megabyte is approximately equal to a million characters' worth of space.) This will give you more than 120 times the storage of an ordinary diskette, but this can pose increased demands in time and money for "backing up" (making second copies for safe-keeping) of software and data. Most home PC-users find that expanding their systems to include two diskette drives and a hard disk/drive meets all their storage needs. Daisies, Dots and Lasers: A Printer's Tale Of course, your PC has a compan- ion printer, probably a dot matrix one that forms characters by imprinting clusters of dots on the paper. Clearly, the greater the number of pins to make the dots, the better-quality the re- sult-and nine-pin printers are rapidly giving way to 24-pin printers. Dot ma- trix printers are relatively fast, and are able to print graphics-an important consideration. Daisywheel printers are quiet and produce typewriter-quality charac- ters; but they're slow and expensive, considering their limitations (the most minimal graphics capabilities). With the advent of more advanced printer technology, they have been steadily losing popularity. Laser printers, certainly the most flexible and highest-quality of all the printers on the market, are also the most expensive. You might consider renting one for such state occasions as master's theses and resume prepara- tions. As you can see, adding on to what you've got can provide the biggest challenge since you unpacked and plugged in that plain vanilla PC of yours. But if you need it and can af- ford it, go for the banana split with cherries on top! Q SPRING 88/plus 15