How to upgrade your PC to a 386 or 486. (Compute's Getting Started with Power Computing)
by Tony Roberts

As applications become more demanding, a computer owner's only recourse seems to be to call for "more power," as the hapless handyman Tim does on TV's "Home Improvement." In these times, more power often means making the jump from a 286- or 386-based CPU to a newer 486.

If you find yourself drumming your fingers, waiting for screen redraws and seemingly interminable disk accesses, it's time to see about beefing up your system so it's not overwhelmed by the software.

Your choices? Buy a new system, upgrade the motherboard, or upgrade the peripheral components. In a perfect world (where money is no object) simply buying a new system makes the most sense. With a new system, you'll have new chips, new memory, new drives, all state of the art.

Buy New, Sell Old

If you shudder when you price a new 486 system, consider raising some cash by selling your old system. If your current computer is in good condition, and isn't too many generations away from the leading edge, you should be able to find a buyer through classified ads in local publications.

There are lots of would-be computer owners out there--who are not as advanced as you--who would be happy to have your old machine if offered at a reasonable price. For years, hard-core computer hobbyists-fed their technology habits by buying and selling systems with every technological advance.

Just be sure to seek a realistic price when selling your old equipment. As you know, prices have come way down, so you won't get anything close to what you paid for it. What you do get, though, will reduce the real cost of upgrading to the new system.

Going the Distance

If you're still not sure you can afford to go first class, perhaps your current system--with a few improvements--can carry you through another year.

If you're a number cruncher, you may find that the addition of a math coprocessor provides the pep you need. Before taking this step, though, make sure that the applications you use take advantage of a math coprocessor.

If you operate heavily in the graphics arena, consider adding an accelerated or coprocessed video board. These boards take some of the strain off of your CPU by performing many of the calculations needed to display complex graphics screens. Windows users report that improving video speed makes a night-and-day difference in system performance.

Upgrading the disk drive is another way to get more power. If your software is disk intensive, a faster, larger hard disk can help. Windows, with all of its file swapping, is extremely disk intensive, as are most large database applications. A few years ago, a hard disk with a 65-milli second access time was the norm. Then 28 milliseconds became the standard. Today, any drive that's slower than 12-16 milliseconds in access time is way too slow.

Memory, too, can improve your system's performance, especially if you use Windows. Many Windows applications say you need 2MB of RAM to run them, but you'll be a lot better off with 4MB or more of RAM. This extra RAM gives your applications room to stretch out, so less swapping to disk is required.

If you can make some or all of these performance enhancements, you may be able to bring your hardware in balance with your software. However, if your system is enhanced to the max, but it still doesn't satisfy you, perhaps a CPU upgrade would solve the problem.

Motherboard Shuffle

By replacing your system's motherboard, you can turn a 286 or 386 into a 486 and derive the benefits that the faster processor, built-in cache, and built-in math coprocessor offer. Many of the components in your old system can be used to build up your new system. But, before you tear into your system, there are a few things to consider.

* The cost. A new 486 motherboard will run anywhere from $500-$1000 depending on whether you want a 486-25, a 486-33, or a top-of-the-line 486-50.

* The components. Using your old video board and disk drives is acceptable, but unless you already have an accelerated video board and a fast disk drive, you'll want to upgrade those items in the near future. You don't want to tie down your fast 486 system with antiquated input/output devices.

* The memory. The memory in your current system may be too slow for use in your new system. Many 386 systems are populated with memory that runs at speeds of 80 or 100 nanoseconds while today's 486 systems use 60- or 70-nanosecond memory.

If you use memory that's too slow for the CPU, you'll have to add wait states to ensure proper operation. Wait states handicap the CPU, so it doesn't outrun the memory's ability to pass information back and forth.

Another factor to consider is how the motherboard uses memory. Many of today's boards permit up to 64MB of memory on the motherboard, but you can't just pop in any amount of memory and expect it to work. Only certain configurations are allowed using combinations of 256K, 1MB, or 4MB Single Inline Memory Modules, or SIMMs. Check the documentation for the motherboard that you're thinking about buying to determine whether the SIMMs in your current system will be usable in the new one. In many cases, you'll have to buy additional memory to fill out memory banks on the new motherboard.

One way or another, there's more power in your computing future. Just follow the path that best fits your circumstances.