EISA Enterprise-IV © 199? AMI [American Megatrends, Inc.]
The Enterprise-IV was a true flagship EISA (Extended Industry Standard Architecture) motherboard designed for high-availability computing. AMI (known primarily for their BIOS) designed these boards to showcase their chipset engineering and their dominance in the BIOS market. The Enterprise-IV is defined by its massive, server-class footprint and its support for complex multi-bus architectures, specifically targeting the 486 platform.
Chipset: AMI’s own custom "Enterprise" chipset, which managed the complex EISA bus and high-speed memory controller.
Bus Architecture: Full EISA (32-bit), offering significantly higher bandwidth and more robust bus-mastering than the standard ISA slots found on your other boards.
CPU Support: Socket 3, optimized for 486DX, DX2, and DX4 processors.
Memory: Typically used high-capacity 72-pin SIMM banks, often supporting parity checking—a requirement for the enterprise/server environments where this board was intended to live.
Form Factor: Large "Full-AT" or "Server" format, often requiring specific deep cases to house the expansive PCB and the additional cooling needed for the EISA controllers.
The "AMI" Advantage: Because AMI was the industry leader in BIOS development, the Enterprise-IV series often had the most "feature-rich" BIOS setup of the era. They included advanced options for bus timing, DMA channel management, and interrupt routing that were simply non-existent on consumer boards from manufacturers like Gemlight or Shuttle.
EISA vs. The World: EISA was essentially the "professional" answer to the IBM Micro Channel Architecture (MCA). While VLB and later PCI eventually won the war, boards like the Enterprise-IV kept the EISA standard alive in high-end server closets for years.