Sidebar: Personal System/2

The Personal System/2 line of IBM computers, or PS/2 for short, was introduced in April 1987. It was in many ways a radical departure from the AT - perhaps too radical. The PS/2 had a number of minor and three major new features: VGA, 1.44MB floppies and Microchannel Architecture (MCA) bus. Let's take a closer look at these three in order: In the first PS/2 generation there were four product lines or models, with each model coming in a number of types with differing amounts of RAM and storage capacity. There were many other PS/2 machines built later, among the more notable ones were Model 90/95 XP - 486s with XGA graphics, introduced in 1990. The XGA was one of the first modern accelerator boards, combining a greatly improved 8514/A accelerator with VGA core. Most accelerator graphics cards from other companies (S3, ATI and others) were very similar to XGA in capabilities. IBM also produced PS/2 portables and later laptops.

The PS/2 line was not as successful as IBM hoped. It did not become the new standard even though many features that first appeared in PS/2 machines did become widespread. But IBM sold millions of PS/2s and and there were even MCA based PS/2 clones from Dell, Tandy and NCR among others. Since IBM lost market dominance, no other leader emerged. Thus some standards introduced in the first PS/2s in 1987 (notably 1.44MB floppies and to some extent VGA) were never replaced by anything better.

The history of PS/2 is intertwined with and somewhat parallel to the history of OS/2 (and the name itself is a big hint). IBM tried to sell PS/2s claiming that they would run OS/2 better - the problem was that OS/2 was not available until nearly a year after the PS/2 line was unveiled. This claim was not quite untrue, the MCA was certainly superior to ISA and OS/2 could make better use of it than DOS. But this also made people think that OS/2 would not run on non-PS/2 machines which was not true (in fact IBM itself was supporting OS/2 on its own AT machines). IBM also couldn't market PS/2s - they were unable to explain to people why they should want PS/2 and MCA.

While PS/2 computers did not take over and the line was ultimately discontinued by IBM, the introduction of PS/2 is without any doubt an important milestone in PC history. A great number of innovations that first appeared in the PS/2 line was adopted by the industry (apart from VGA and 1.44MB floppies there were for instance PS/2 keyboards and mice or PS/2 72 pin memory modules). PS/2 machines were built to last and some of them are still happily running, years and years after they were built, a tribute to IBM's conservative, built-to-last engineering so unpopular these days.


The information presented here was mostly gleaned from 1987 issues of PC Tech Journal which described PS/2 machines in great detail.