Which Operating System
Should You Purchase
— Is OS/2 Presentation Manager Better Than DOS Windows

by Lloyd Borrett
Technical Cornucopia, September 1990

With the rapid changes happening in the PC marketplace, an often asked question today is, "Which operating system should I use?" The three contenders are DOS, OS/2 and Unix.

Arguments fly back and forth as to whether DOS with Windows is as good a graphical user interface as OS/2 with Presentation Manager. And, when it comes time to consider networked desktop computers, arguments start as to whether the multi-tasking and connectivity capabilities of OS/2 are as good as those of Unix.

Clearly the common denominator in both areas is OS/2. As the newest operating system on the block it is the least understood. So let's take a closer look at how OS/2 stacks up against its older rivals.

Is Presentation Manager
Better Than Windows?

Most of you probably will be familiar with Microsoft Windows. Essentially it's Microsoft's very successful attempt to give DOS a graphical user interface (GUI). Software developers write their applications to run in the Windows environment and instead of having to implement their own unique screen, printer, mouse, and other device drivers, they can use the drivers built into Windows.

As the software developers are using standard toolsets to display information and accept input, the applications themselves often have a common look and feel. Users familiar with one Windows based applications find it easier to learn a second Windows based application.

Certainly there are many impressive applications now available that use the Windows environment. Many of these products, such as Aldus PageMaker, started life on the Apple Macintosh but were later ported to run on DOS based PCs using the Windows graphical user interface.

However, a graphical user interface also introduces system overheads. More processing needs to be done to display the information in graphical form, thus 386SX based PCs should be considered the minimum platform for most Windows based applications. Few users tolerate the performance of Windows on an 8088/8086/80286 based PC, and many users opt for the added power of 386SX, 386 and 486 based systems.

The Windows environment also adds memory overheads to the system. As most of the major software developers are already struggling to fit their applications into the 640Kb DOS base memory area, that can be a real problem. Couple it with the memory overheads of linking machines together on a network, which is a typical requirement in today's business environment, and the problem often becomes unworkable.

The OS/2 operating system was designed to solve this problem. It delivers real multi-tasking capabilities rather than inadequate kludges designed to make DOS seem to be multi-tasking. A key part of OS/2's development has been the Presentation Manager graphical user interface.

With the introduction of Microsoft Windows 3.0, the graphical user interface looks very similar to the OS/2 1.2 Presentation Manager interface. In time you can expect the two to become even more alike.

So really there is no point comparing Windows and Presentation Manager. What needs to be compared is the nature of the operating system that each runs with.

The simple fact is that Windows has to run with all of the limitations imposed on it by the underlying DOS operating system. Applications written to run using OS/2 Presentation Manager will have few of these limitations.

When listening to project leaders controlling the development of OS/2 Presentation Manager based applications, one often learns that their biggest problem is deciding what new features they must leave out of the next release in order to get the product out into the marketplace in a timely fashion. There is so much room to implement features, it becomes overwhelming!

That's a very different situation than that faced by developers of DOS and Windows based applications. Their biggest problem is how to make the code they must have, actually fit. So great is the problem that we've seen most of the leading software developers miss critical deadlines with recent product upgrades and new releases.

Most applications running under OS/2 Presentation Manager run dramatically faster than the same applications running under DOS based Windows. Just compare the performance of OS/2 Presentation Manager based Excel with the Windows version of Excel, or likewise the OS/2 and DOS versions of Aldus PageMaker and Ventura Publisher.

When the new OS/2 1.2 High Performance File System is used in place of the old DOS FAT file system, we see further increases of between 30 percent and 400 percent on disk access speeds alone! When the version of OS/2 tailored to make use of the additional power of the 386 and 486 based PCs ships next year, the performance difference will grow even greater.

Not everybody needs their PC to be connected to other PCs, and to have extremely powerful software solutions. Their work is such that it's not justified given the benefits they can expect. For them, Windows will deliver the added benefits of a graphical user interface.

But an ever increasing number of people are finding the limitations of DOS too restrictive. As the OS/2 versions of the programs they use become available they will switch from DOS to OS/2 and never look back.

Is Presentation Manager better than Windows? Of course it is. But, for the end-user it's not because of any great differences in the way the graphical user interface looks to them. It's the nature of the underlying operating systems that make the difference.

In summary OS/2 Presentation Manager is the strategic graphical user interface choice for the future. Windows is the short term tactical option to get IBM standard computing users to accept a graphical user interface. OS/2 Presentation Manager is the right choice for the '90s.

Buy a 386/486 based system that can run OS/2 well. Install both operating systems, OS/2 and DOS, and use the OS/2 versions of applications where available. Then you get the best of both worlds.