IBM PS/2

IBM PS/2. The IBM Personal System/2, announced in April 1987, was a major attempt by IBM to regain control of the personal computer architecture it had pioneered with the IBM PC. The line introduced several advanced technical standards, most notably the Micro Channel architecture (MCA) bus and the Video Graphics Array (VGA) display standard, which became long-lasting industry fixtures. Despite its technological innovations, the PS/2 line faced significant market resistance from clone manufacturers and ultimately did not achieve its goal of re-establishing IBM's dominance in the market.

History and development

The development of the PS/2 series was driven by IBM's desire to reclaim the architectural leadership it had ceded to clone makers like Compaq and Dell following the success of the original IBM PC. Led by executives such as William C. Lowe and a team in Boca Raton, Florida, the project aimed to create a proprietary, technically superior platform. The launch event in April 1987 was a major industry spectacle, heavily covered by publications like PC Magazine and InfoWorld. This strategic shift was a direct response to the competitive pressures from the IBM PC compatible market, which had eroded IBM's profits and market share throughout the mid-1980s.

Technical specifications

The PS/2 series was defined by several proprietary technical advancements. Its core was the Micro Channel architecture, a 16- or 32-bit bus that offered superior performance and bus mastering compared to the legacy Industry Standard Architecture (ISA) bus. The systems universally introduced the 1.44 MB 3.5-inch floppy disk drive as a standard. For graphics, the integrated Video Graphics Array adapter provided high-resolution 640x480 pixel displays and a rich 256-color palette from a much larger total, a significant leap over the previous Enhanced Graphics Adapter. Other notable features included the dedicated keyboard and mouse port connector, improved reliability from surface-mount technology, and a new layout for the 101-key Model M keyboard.

Models and variants

The PS/2 line encompassed a wide range of models targeting different market segments. Initial models included the budget-oriented Model 25 and Model 30, based on the Intel 8086 processor, and the more powerful Model 50 and Model 60, which used the Intel 80286. High-end desktop and workstation models like the Model 70 and Model 80 were powered by Intel 80386 and Intel 80486 processors. IBM also produced specialized variants, such as the portable Model P70, the server-oriented Model 95, and the sleek Model 55SX. Later, cost-reduced models that reverted to the ISA bus, like the Model 35 and Model 40, were introduced to compete more directly with clone PCs.

Impact and legacy

The impact of the PS/2 was profound yet paradoxical. While its proprietary Micro Channel architecture failed commercially, many of its other innovations became universal de facto standards. The VGA display standard dominated personal computer graphics for over a decade and formed the basis for successors like Super VGA. The small, round keyboard and mouse connectors became ubiquitous on motherboards for nearly twenty years. The line also accelerated the development of OS/2, a joint project with Microsoft intended to be its flagship operating system. Ultimately, the market's rejection of MCA cemented the dominance of open standards like ISA and later PCI, ensuring the continued reign of IBM PC compatible systems from companies like Compaq and Gateway, Inc..

Operating systems and software

The PS/2 was designed to run a new generation of software, primarily IBM's OS/2 operating system developed in partnership with Microsoft. It also shipped with IBM PC DOS and supported Microsoft Windows 2.x and later versions. Key software demonstrations at launch highlighted the capabilities of OS/2 and Presentation Manager. However, the high hardware requirements and slow adoption of OS/2 led many users to run the more familiar MS-DOS and Microsoft Windows environments instead. This software divide mirrored the hardware conflict, as developers largely continued to target the broader ISA-based IBM PC compatible market rather than the exclusive Micro Channel architecture platform.

Category:IBM personal computers Category:Computer hardware introduced in 1987 Category:Discontinued IBM products