People in the market for a personal computer often face a dilemma. They don't want to buy something that will soon be obsolete, but they hate to waste money on a machine that's more powerful than they need.
For some, the answer is a computer that's easy to upgrade. Let's look a bit at what that means.
Most people who buy IBM compatible desktop systems these days are buying machines with a 386 central processing unit TC (CPU) or the slightly slower 386SX. Those are fine for most situations, but there are some programs that work better on faster CPUs. Also, people's standards change as they become more experienced. A machine that's fine for a new user may seem a little sluggish down the road.
Of course you can always buy a machine with a faster CPU than you think you need, but that can be a waste of money. There's no point in having a fast machine if you're not using software that takes advantage of it. Most regular MS-DOS programs such as WordPerfect 5.1 or Lotus 1-2-3 run very well on a 386SX machine. Most people won't notice the extra performance of a faster machine. Microsoft Windows runs OK but is a little sluggish on a 386SX. If you're doing computer-aided design, desktop publishing or working with very large spreadsheets or data bases, you're likely to appreciate a faster machine.
Until recently it was somewhere between difficult and impossible to change a computer's CPU. At best, it involved taking apart the machine, carefully removing the old CPU and inserting a new one, being careful not to bend any pins. But now you can buy PCs that have been designed with upgrading in mind. Positive Corp., which sells its machines through membership discount stores such as Price Club, Pace and Sams, has recently introduced a system that is both affordable and easy to upgrade.
The machine comes without a CPU. Instead, there is a slot in the front to accommodate a CPU cartridge. It's very easy to change it. You don't even have to remove the case. You simply press two buttons on the bottom of the machine, slide off a plastic front panel and pull out the cartridge. The entire process takes only a few seconds and doesn't require any tools.
The basic machine costs $1,400 without a CPU. It comes with 4 megabytes of RAM, a 105-megabyte hard disk, two (3 1/2 and 5 1/4 -inch) floppy disk drives, a Super VGA color monitor, a mouse and a 2400 baud internal modem. The parallel port, two serial ports, the monitor connector and disk drive controller are built in, leaving six empty expansion slots for additional equipment. Another model, which costs $1,900, comes with 8 megabytes of RAM, a 200-megabyte hard disk and a fax/data modem. Both models come with Microsoft Windows 3.0, DOS 5.0, Microsoft Works for Windows and Prodigy software installed on the hard disk.
Be sure to add the CPU prices when comparing these machines to other brands. Also, when price shopping, compare these prices to the "street" prices of other systems. Many companies inflate their suggested retail prices to allow for dealer discounts. The Positive brand is already priced for discount stores.
Positive currently offers four CPU cartridges: a 20 megahertz 386SX ($199); a somewhat faster 20 Mhz 386SX with a cache ($349); a 20 Mhz 486SX ($699), and a 33 Mhz 486DX ($1,099). The company plans to release a 50 Mhz 486 CPU later this year. Customers who upgrade will receive a partial credit when they return their used CPU cartridge.
I tested the machine and all of the optional cartridges and found its performance to be on par with similarly equipped systems. The least expensive configuration (with the 20 MHz 386SX CPU) runs 10 times faster than the original IBM PC, according to Norton Computing's System Information program. The 33 Mhz 486 CPU runs 71 times faster. Changing CPUs did not require any changes in software or system configuration. All my programs ran with all the CPUs.
There are several advantages to this type of upgrade strategy. To begin with, you don't have to buy more than you need or can afford. You can upgrade later and, by waiting, you may be able to take advantage of the general decline in the price of CPUs. Although nothing has been announced, it is widely assumed that the 486 chip will be less expensive later this year.
(Positive Corp., Chatsworth, Calif., (800) 252-6345.)