What About Windows 95?

OS/2 is often compared to Windows 95, and it does seem that these OSes are each others' main competitors in the desktop marketplace. It should first be noted that OS/2 can not use Windows 95 to run Windows programs, and probably never will; OS/2 "for Windows" relies upon very specific things about Windows 3.1 to be able to use it for running Windows programs, and these things have changed with Windows 95. The current release of OS/2 will only run those Windows 95 programs which will run under Windows 3.1 with the Win32s extensions, and OS/2's Win32s subsystem doesn't run 100% of all Win32s applications. Note, however, that many of the programs being marketed today as "for Windows 95" fall into this category, and OS/2 will run most of them. If in doubt, check the box's requirements carefully to see if the program will run under Windows 3.1, or post to an appropriate OS/2 newsgroup.

In terms of features, abilities, and system requirements, Windows 95 is very similar to OS/2 in many ways. RAM requirements, pre-emptive multitasking, an object-oriented "desktop" environment [though Windows 95's is object-oriented in only a "skin-deep" sort of way], and other features exist in both OSes. Here, then, are some of the major differences:

• HPFS. OS/2 allows the use of HPFS, which is a giant leap forward in disk software technology, compared to FAT, especially on larger drives. Windows 95 allows the use of "VFAT," which is an extension to FAT which allows long filenames; but few of FAT's other numerous shortcomings are addressed by VFAT. Thus, people with large drives (say, larger than 512MB) should favor OS/2 over Windows 95. OTOH, VFAT drives can easily be read from DOS, which may be a concern for some people; HPFS requires special drivers to be read from DOS. The latest version of Windows 95 (available only on pre-loads) also includes VFAT-32, which fixes the massive waste of disk space problem on large drives that's existed in FAT and VFAT up until now.
• Drivers. Windows 95 allows the use of existing DOS drivers for many devices, which should alleviate the driver availability problems which have historically plagued OS/2. Using DOS drivers in Windows 95, however, may slow its performance and make it more crash-prone.
• Hardware. Windows 95, while technically a 32-bit protected-mode OS, actually utilizes much older 16-bit, real-mode code. Thus, while it puts more demands on hardware than does DOS, it may exhibit fewer problems on flakey hardware than OS/2. On the other hand, Windows 95 has its own idiosyncracies, and I've seen posts which indicate problems under Windows 95 on systems which run OS/2 fine, as well as vice-versa.
• Software. Currently, there are more OS/2 programs than Windows 95 programs; and companies have been developing OS/2 programs for longer than they've been doing any 32-bit Windows programs, so the earliest 32-bit Windows 95 programs are crude compared to existing OS/2 software. There are an increasing number of Windows 95 programs appearing on store shelves, but many of these are actually Win32s programs that run under OS/2 as well as under Windows 95. As noted earlier, however, OS/2 software can be difficult to locate. Check Indelible Blue for a sampling of commercial OS/2 software.
• DOS program settings. I confess to less-than-perfect knowledge about how Windows 95 handles DOS programs, but my impression is that OS/2 is more flexible in its ability to specify different parameters than Windows 95.
• Multitasking. While both OSes use pre-emptive multitasking, OS/2 implements this feature much more completely than does Windows 95. Specifically, many Windows 95 system calls are "non-reentrant," which means that they can only be called by one program at a time. This may produce some "jerkiness" to the multitasking of Windows 95. Of potentially greater concern, Windows 95's multitasking performance drops radically when even a single 16-bit Windows 3.1 program is run, whereas OS/2's multitasking will not be adversely affected in this case.
• Protection. Like OS/2, Windows 95 provides protection between different programs. Unlike OS/2, however, Windows 95's protection applies only to 32-bit Windows programs; the existing base of 16-bit Windows programs does not benefit from this, and in fact such programs, if buggy, can much more easily bring down Windows 95 than they can bring down OS/2. How serious this problem is in practice I don't know, however.

I've seen a number of comparisons in the computer press between OS/2 and Windows 95. Unfortunately, many of them use subtly (or not-so-subtly) biased measures, such as using Win32 disk benchmark programs (generally using FAT for both OSes) or comparing video speed based upon OS/2's seamless video modes (see above). Most, but not all, such comparisons also utilize only single-tasking performance. When reading such comparisons, read them very carefully, and take them with a rather substantial grain of salt.

There have been many reports of OS/2 and Windows 95 coexisting on the same machine, much as OS/2 and DOS can. You can therefore get "the best of both worlds," if you don't mind the expense and time investment this would entail. Such a setup requires the use of Boot Manager or a third-party boot utility like the shareware Advanced Boot Manager or the commercial System Commander rather than Dual Boot. IBM maintains a document called Just Add OS/2 Warp which covers installing OS/2 on a system with Win95.