MPU BOARD GENERAL DESCRIPTION The following is a brief description of the MPU hardware and operating system. (See Figure 1-1.) MPU Board Hardware The MPU board is a single-board host computer that provides central control and memory for an instrumentation system. It is based on a Motorola 68010 microprocessor, 2 Mbyte or 4 Mbyte RAM, and 64 Kbyte boot ROM. The MPU board provides a modified RS-232 port for keyboard communications and a standard RS-232-C port for host communications. It also provides a generic Tektronix 1200-Series COMM Pack port for RS-232-C, GPIB, and printer interfacing. A 640 X 400, non-interlaced display output provides connection for an external monitor. A hard disk drive (optional for the PRISM 3001 Series mainframes) is connected to the MPU board for mass storage. All application modules within a Mainframe system connect to either the MPU board or an Expansion board via TekLink cabling. Service information for the Expansion board is located in the PRISM 3002 Series Mainframes and 2510 TestLab Mainframe Service Manual. Refer to Section 4: Theory of Operation in this manual for detailed descriptions of MPU board circuit operation. MPU Board System Software System software is based on a real-time operating system (pSOS). The MS-DOS compatible file system is optimized for use in an instrumentation environment. A full set of general-purpose utilities supports the menu-based user interface. Basic external communications software provides instrument control and transfer of binary information. Comprehensive diagnostic software supports both automatic power-on tests and menu-driven self-tests.