Advances in technology are generally good news for computer buyers.
Every day, manufacturers issue computers that are cheaper, faster, smaller, lighter and more powerful than the machines on the market last week.
But sometimes, buying the latest and greatest can work to your disadvantage. Take the matter of "downsizing," as it's known in the trade.
The original IBM PC was a big, ungainly thing. It weighed half a ton and occupied 330 square inches of desktop real estate. Its very size was intimidating.
Today, you can buy a six-pound laptop computer with 20 to 30 times the power of the original PC in a package the size of a notebook. For people who prefer full-size screens and keyboards, desktop computers have shrunk to the size of a pizza box.
Since American consumers vote the smaller-is-better ticket, the pizza box computer is becoming increasingly popular. Unfortunately, a pizza box may not always be a good buy. When something goes wrong with the machine, you may wish you had an old behemoth.
While I've never been a great fan of IBM hardware, Big Blue's engineers had a sound idea when they put the original PC together. The machine was designed to be expandable.
The original IBM PC was nothing more than a main circuit board inside a metal case. IBM called the main circuit board the "planar." Everyone else called it the motherboard.
All the equipment you needed to make the computer do something useful -- video display circuitry, disk controllers, printer and serial ports -- came on circuit cards that plugged into expansion slots on the motherboard.
Because the technology was new, the early expansion boards were fairly large. You also needed room for at least half a dozen of them -- hence the large motherboard and case.
While this wasn't the most efficient use of space, the PC's modular design had significant advantages. You could build your computer from scratch and change it whenever the mood struck you.
If you started off lean and mean with a monochrome video card, you could upgrade to color by pulling out one circuit card and plugging in another -- a five-minute job. If you needed another disk drive, no sweat -- you just opened the case, slid it in and hooked it up.
This standardization also gave rise to the PC clone. Once manufacturers learned to duplicate the IBM motherboard, anyone with a screwdriver could build a computer from off-the-shelf components. PC manufacturing suddenly became a cottage industry, and prices plummeted. A powerful computer was no longer a rich man's tool.
Likewise, modular design made equipment failures easier to live with. If a non-critical part such as a printer port blew up, you could still use the computer until you had time to get it fixed.
If you were handy, you could replace the circuit card without taking the computer to the shop. If you did got to the shop, standardized parts from a variety of sources made repairs quick and relatively inexpensive.
This is changing today, for better or worse. Customized, large-scale integrated circuits now give one chip the power of many. With these chips, it's just as cheap for big manufacturers to include video circuitry, serial ports, parallel ports and disk controllers on the motherboard as it was to use separate circuit cards a few years ago. It's often cheaper.
In fact, it's now possible to stuff a full computer's worth of electronics on a single board not much bigger than a floppy disk. With most of the hardware that people want already on the motherboard, PC's also need fewer expansion slots.
This means the physical size of the case is determined by how much room your disk drives, power supply and a couple of expansion
slots require. For a minimal computer system, it's not much.
I recently saw a desktop unit with a hard disk and a floppy drive that's 10 inches wide, 9 inches deep and just over an inch high. My 8-year-old can eat more pizza than that.
Smaller, lighter, cheaper. So far, so good. But what happens when something goes wrong?
Say your video card goes on the blink. It happened to me a few weeks ago. I have a generic clone of the older design. It's big and ugly. But I went to the nearest computer store, bought a video card for $89 and installed it in five minutes.
If I'd had one of the new, integrated machines with the video on the motherboard, I would have had to find a repair shop that handled that particular brand of computer.
The shop would have had to repair the main circuit board -- an expensive and technically difficult job -- or possibly replace the board entirely. We're talking hundreds of dollars here, especially if you're limited to the boards from the original manufacturer.
Not surprisingly, manufacturers love this state of affairs. They can build computers for less money and tie you to their repair networks and parts for life.
Expansion may also be a problem. At the very least, a computer should have enough room for a hard drive and two floppies -- one 3 1/2 -inch drive and one 5 1/4 -inch drive.
But if that's all the room you have, what happens when your hard drive fills up? They always do. Those big old boxes had plenty of room for extra drives. If your drive bays are all occupied, you'll have to throw away the drive you have and spend a lot more for a disk with twice the capacity.
If you use your computer for serious business applications, a tape backup is almost a necessity. But if you don't have room for a tape cartridge in your pizza box, you'll have to buy a more expensive external tape drive -- provided you also have an expansion slot for the controller. I could go on, but you get the point.
Don't be seduced by less-is-more. Unless space is at an absolute premium, buy a computer that anyone can fix. And buy one with enough room to accommodate your computing future as well as the present.