Three ways to upgrade: they're costly, but a lot cheaper than a new system. (one of six articles in DOS to OS-2 special report)

THREE WAYS TO UPGRADE

If you can believe what most vendors are saying, a new wave of powerful software is coming your way. That software will run under OS/2, but it won't run on your IBM PC or PC XT as currently configured. Is it time to trade in your PC XT for a Compaq Deskpro 386 or for an IBM PS/2 Model 50? Not necessarily.

You may want to go with one of the new generation of 80286- or 80386-based boards instead. The distinguishing feature of the new boards is their ability to run OS/2. Older boards, such as Intel's Inboard 386 PC and Quadram's Quad 386 XT, only speed up your PC or XT; they cannot run OS/2.

The new boards also speed up DOS applications, including 1-2-3 and Symphony. The microprocessor's speed largely determines how quickly 1-2-3 and Symphony recalculate your worksheets. Replacing your XT's 8088 with a faster 80286 or 80386 microprocessor accelerates operations considerably.

It also speeds up the disk, but not quite as much. Savings and retrieving worksheet files involves both computation and reading and writing data. While the boards don't increase the speed with which the disk drive actually reads or writes, they significantly speed up the computations associated with those operations. Operations that involve more computation will work that much more quickly; unfortunately, operations requiring less computation benefit less. In addition, some of the upgrade boards include what's known as disk-cache software, which helps your hard disk retrieve files more rapidly.

What It Takes

If you want to run OS/2, in most cases you'll need to add much more to your system than a '286 or '386 card. That will cost you, but the bill will be significantly smaller than the tab for a new computer.

Suppose you have an IBM PC XT equipped with 640K of memory, a 360K 5-1/4-inch floppy-disk drive, a monochrome or monochrome graphics display, and a 10- or 20-megabyte hard disk. To equip this machine to run OS/2, you need an 80286 or 80386 …