Xycom XVME-678 is a VMEbus-based PC/AT processor module designed to provide a standard IBM PC/AT computing environment within VMEbus systems. The following outlines its core features and technical specifications:

1. Processor and Performance

• Equipped with a 25 MHz Cyrix 486SLC/e CPU, instruction-set compatible with the 486SX, featuring 1 KB of on-chip cache.
• Supports up to 16 MB of DRAM with zero-wait-state interleaved page access. Factory configurations include 0, 1, or 4 MB, expandable to 2, 10, or 16 MB.

2. Bus and Interfaces

• Fully compliant VMEbus double-high single-board design, occupying one slot (P1 or P1+P2).
• Provides standard PC/AT I/O:
  • VGA (P10)
  • Serial ports COM1/COM2 (P9, P8)
  • Parallel port (JK1)
  • Keyboard controller and speaker
  • IDE hard-disk interface (P5)
  • Floppy-disk controller (P4)
• Includes an optional 80387SX math coprocessor socket (U7).

3. BIOS and Software Compatibility

• Uses a Quadtel AT-compatible BIOS with a BIOS setup menu; access via <Ctrl+Alt+S>, and soft-key lock via <Ctrl+Alt+L>.
• BIOS parameters are stored in battery-backed CMOS, retaining configuration after power loss.
• Fully compatible with all standard PC/AT software and operating systems.

4. Mechanical and Power Characteristics

• Double-high module with dimensions compliant with VME chassis requirements.
• Low-power CMOS design, with an on-board battery to maintain CMOS settings.

5. Optional Expansion

• Can be used with the Xycom XVME-955 hard-disk/floppy module, which provides a 3.5-inch IDE hard drive and a 1.44 MB floppy drive within two slots.
• Supports an 80387SX coprocessor, additional DRAM expansion, and custom jumper configurations.

6. Typical Applications

• Industrial control and data acquisition systems requiring PC/AT software operation on a VMEbus platform.
• Embedded computing environments that demand reliable real-time I/O and high-speed bus interconnection.

Summary

The Xycom XVME-678 integrates a complete PC/AT computing platform into the VMEbus, delivering a highly compatible and flexible solution for industrial automation, laboratory instrumentation, and embedded systems. With its 25 MHz Cyrix 486SLC/e processor, optional math coprocessor, and rich set of standard I/O interfaces, it is capable of running traditional PC software while fully leveraging the high-speed data-transfer capabilities of the VMEbus.