HP 3000

The HP 3000 series^[1] is a family of 16-bit and 32-bit minicomputers from Hewlett-Packard.^[2] It was designed to be the first minicomputer with full support for time-sharing in the hardware and the operating system, features that had mostly been limited to mainframes, or retrofitted to existing systems like Digital's PDP-11, on which Unix was implemented. First introduced in 1972, the last models reached end-of-life in 2010, making it among the longest-lived machines of its generation.

The original HP 3000 hardware was withdrawn from the market in 1973 to address performance problems and OS stability. After reintroduction in 1974, it went on to become a reliable and powerful business system, one that regularly won HP business from companies that had been using IBM's mainframes. Hewlett-Packard's initial naming referred to the computer as the System/3000, and then called it the HP 3000.

The HP 3000 originally used a 16-bit CISC stack machine processor architecture, first implemented with Transistor-transistor logic, and later with Silicon on Sapphire chips beginning with the Series 33 in 1979.^[3][4] In the early 1980s, HP began development of a new RISC processor, which emerged as the PA-RISC platform. The HP 3000 CPU was reimplemented as an emulator running on PA-RISC and a recompiled version of the MPE operating system. The RISC-based systems were known as the "XL" versions, while the earlier CISC models retroactively became the "Classic" series. The two sold in tandem for a short period, but the XL series largely took over in 1988. Identical machines running HP-UX instead of MPE XL were known as the HP 9000.

HP later renamed the computer the HP e3000 to emphasize the system's compatibility with internet and web uses.^[5] HP initially announced the systems would be designated to be at end-of-life at HP in 2006, but extended that several times to 2010. The systems are no longer built or supported by the manufacturer, although independent companies support the systems.