IBM Personal System/2

IBM Personal System/2. Introduced in April 1987, the IBM Personal System/2 represented a major strategic shift for International Business Machines Corporation in the personal computer market, aiming to regain control of the architecture it had pioneered with the IBM Personal Computer. The line was defined by its new, proprietary Micro Channel architecture bus, improved graphics standards, and a strong push for its new OS/2 operating system developed with Microsoft. While it achieved significant corporate adoption and introduced lasting technologies, its closed architecture ultimately failed to halt the dominance of IBM PC compatible clones from companies like Compaq and Dell.

History and development

The development of the Personal System/2 was driven by IBM's desire to reassert its leadership in a market it had created but was rapidly losing to clone manufacturers. Following the success of the open-architecture IBM Personal Computer AT, competitors had reverse-engineered the Industry Standard Architecture bus and BIOS, creating a vast market for IBM PC compatible machines. Under the leadership of executives like William C. Lowe and later James A. Cannavino, IBM's Entry Systems Division in Boca Raton, Florida initiated the project, codenamed "Leapfrog," to create a technologically superior and legally protected system. The launch event in April 1987 was a major industry spectacle, intended to make the existing IBM Personal Computer XT and AT lines obsolete and set a new, proprietary standard for the next decade of computing.

Technical specifications

The most significant technical departure was the proprietary 32-bit Micro Channel architecture bus, which offered superior performance and bus mastering capabilities compared to Industry Standard Architecture. The line introduced several enduring standards, including the 3.5-inch floppy disk format, the PS/2 connector for keyboards and mice, and the Video Graphics Array display standard, which became ubiquitous. Models were powered by a range of Intel processors, from the Intel 8086 in entry units to the Intel 80486 in high-end servers. Memory configurations varied widely, and storage options included hard drives from vendors like Western Digital, with higher-end models supporting SCSI interfaces.

Models and variants

The initial launch comprised four primary model series: the low-end Model 30, the mid-range Models 50 and 60, and the high-end Model 80. The Model 30, based on the Intel 8086, retained the old Industry Standard Architecture bus to maintain software compatibility, while the Models 50 and 60 used the Intel 80286 and the Micro Channel architecture. The flagship Model 80 featured the new Intel 80386 processor. Subsequent expansions included the compact Model 25, the L40 SX laptop, and powerful server versions like the IBM Server/295. Specialized variants, such as the Model 55 SX, filled out the lineup, and later iterations incorporated Intel 80486 processors and enhanced graphics subsystems.

Operating systems and software

IBM heavily promoted its new OS/2 operating system, developed jointly with Microsoft, as the strategic software platform for the Personal System/2, touting its advanced capabilities like preemptive multitasking. However, the systems also shipped with IBM PC DOS and were compatible with Microsoft Windows 2.x and later versions, as the clone market continued to standardize on the DOS-Windows combination. Key bundled software included IBM Personal System/2 DisplayWrite for word processing. The architectural shift caused initial software and hardware compatibility issues, particularly for expansion cards, which required expensive Micro Channel architecture-specific versions.

Impact and legacy

The Personal System/2 had a profound but paradoxical legacy. While commercially it failed to reclaim market share from clones, many of its hardware innovations became universal Personal computer standards, most notably the PS/2 connector and Video Graphics Array. The Micro Channel architecture itself, while a commercial failure in the desktop space, influenced later server and workstation designs. The project's cost and the industry's rejection of its closed model accelerated IBM's loss of dominance in the personal computer sector, contributing to the company's financial struggles in the early 1990s and a strategic shift toward services and software under Louis V. Gerstner, Jr..

Reception and market performance

Initial critical reception from publications like PC Magazine and InfoWorld was mixed, praising the advanced engineering and graphics but criticizing the high cost, proprietary nature, and compatibility hurdles. The corporate market, particularly large enterprises loyal to International Business Machines Corporation, adopted the systems widely, valuing the improved reliability and manageability. However, the broader market and clone manufacturers largely rejected the Micro Channel architecture, refusing to pay licensing fees. This cemented the victory of the open IBM PC compatible standard, with companies like Compaq, AST Research, and Gateway 2000 flourishing. Production of most models ceased by 1995, marking the end of IBM's attempt to control the personal computer hardware architecture. Category:IBM personal computers Category:Personal computers Category:1987 introductions