Twenty-five years ago, on March 31st, 1992, IBM released OS/2 2.0, the first mass-market 32-bit PC operating system. The road to OS/2 2.0 was quite long and winding, and the OS was a proud member of the vaporware club (just like, say, Windows NT or Windows 95).
Talk of 32-bit OS/2 goes almost as far back as OS/2 itself. In 1987, Gordon Letwin wrote about OS/2-386 in Inside OS/2 and it is clear that future 32-bit extension was a consideration when OS/2 1.0 was on the drawing board. And we now know that in late 1986, Microsoft already started experimenting with using the 80386’s V86 mode to run Virtual DOS Machines (VDMs) on top of OS/2.
Microsoft launched actual development of OS/2 2.0 probably in 1988, the same year development of NT OS/2 (later known as Windows NT) started. The goal was to provide a PC operating system which is upwardly compatible with OS/2 1.x, supports native 32-bit applications, and supports VDMs; the latter was especially important in light of the fact that compatibility with existing DOS applications was a weak point of OS/2 1.x.
The entire history of OS/2 2.0 development is one of missed deadlines and broken promises. In July 1988, OS/2 2.0 was supposed to be released in early 1989. In February 1989, an OS/2 2.0 SDK was supposed to be released by the end of the year and the finished product in 1990. Continue reading