The System 9000 (S9000) is a family of microcomputers from IBM consisting of the System 9001, 9002, and 9003. The first member of the family, the System 9001 laboratory computer, was introduced in May 1982 as the IBM Instruments Computer System Model 9000. It was renamed to the System 9001 in 1984 when the System 9000 family name and the System 9002 multi-user general-purpose business computer was introduced. The last member of the family, the System 9003 industrial computer, was introduced in 1985. All members of the System 9000 family did not find much commercial success and the entire family was discontinued on 2 December 1986. The System 9000 was based around the Motorola 68000 microprocessor and the Motorola VERSAbus system bus. All members had the IBM CSOS real-time operating system (OS) stored on read-only memory; and the System 9002 could also run the multi-user Microsoft Xenix OS, which was suitable for business use and supported up to four users. Features There were three versions of the System 9000. The 9001 was the benchtop (lab) model, the 9002 was the desktop model without laboratory-specific features, and the 9003 was a manufacturing and process control version modified to be suitable for factory environments. The System 9002 and 9003 were based on the System 9001, which was based on around an 8MHz Motorola 68000, and the Motorola VERSAbus system bus (the System 9000 was one of the few that used the VERSAbus). Input/output ports included three RS-232C serial ports, an IEEE-488 instrument port, and a bidirectional 8-bit parallel port. For laboratory data acquisition, analog-to-digital converters that could be attached to its I/O ports were available. User input could be via a user-definable 10-key touch panel on the integrated CRT display, a 57-key user-definable keypad, or a 83-key Model F keyboard. The touch panel and keypad were designed for controlling experiments. All System 9000 members had an IBM real-time operating system called CSOS (Computer System Operating System) on 128KB of read-only memory (ROM). This was a multi-tasking operating system that could be extended by loading components from disk. IBM also offered Microsoft Xenix on the System 9002, but this required at least 640KB of main memory and a VERSAbus card containing a memory management unit. The machines shipped with 128KB of main memory as standard, and up to 5MB could be added to the system using memory boards that plugged into the VERSAbus.