I found this while searching for the BIOS ID. I think it's the right board, but this one says it has a PS/2 mouse connector and 2 USBs. It'll be one that slips into a bay with a cable running to the mobo won't it? If so I don't know why it would be missing as there doesn't seem to be a reason for the original owners to take it.
M520 v1.0 Pentium Motherboard
- Award Bios id string 08/26/96-i430VX-2A59Ht5BC-00
- 4-72 pin SIMM slots (8-128MEG FPM/EDO)
- 1-168pin DIMM slot (8-64MEG DRAM/SDRAM/EDO)
Additional notes on this board available by email request
- 3-32bit PCI Bus slots
- 4-16bit ISA slots
- 160pin 256K/512K pipeline cache COAST 3.0+ module optional
- AWARD Auto-Detect Flash Bios with Energy Mgmt.
- Supports LBA Mode Control & Large Disk DOS Compatibility.
- Green PC Connector
- PS/2 Mouse Connector
- USB connectors
- Intel Triton PCIset SB82437VX chipset
- DALLAS DS12887A Real Time Clock with builtin cmos battery
- P55c Voltage Regulator Module (VRM) optional
- Supports 3.3v/3.5v CPU's and clock speeds 1.5x/2x/2.5x/3x.
- 321pin ZIF socket 7 which supports these processors:
INTEL Pentium P54C-75/90/100/120/133/166/180/200 MHz, P55C w/VRM
Cyrix/IBM 6x86 P120+/P150+/P166+, AMD K5 PR75~PR166 CPUs
- Supports 50/60/66 MHz external clock speeds
- Multi-I/O chip supports:
2 PCI Enhanced IDE Ports (Supports 4 Devices PIO 0-4)
2 High Speed Serial Ports (16550 UART Compatible)
1 Enhanced Parallel Port (SPP, EPP, ECP capable)
1 Floppy Drive Port (Supports 2 Floppy Drives)
- Manufactured by: 1437 Hsing Tech Enterprise Co., LTD.
- Sold as: Ability, Amptron, Aristo, Eurone/Matsonic, Houston Tech,
PCWare(Alton), Protac, PcChips, and Sybercom