#60
Manufacturer: ??? (possibly SOYO)
Chipset: UM8498F + UM8496F
BIOS string: 12/08/94-UMC-498GP-2C4X6S21-00
BIOS label: BIOS ISA 486
BIOS version: Award Modular BIOS v4.50G
Sorry for ebay watermarked photo, I'm unable to make any better one at the moment so the seller's photo will have to do.
This seems to be a cheap mobo with minimal BIOS options. It's in a pretty sorry state and I only bought it for parts, but decided to try and fix it to see (with a POST card) if the CPU actually works.
I got it to boot though so with keyboard working I run some tests - here's quick notes before it gets disassembled:
- BIOS has HDD detection, seems to support HDDs >504MB by allowing head count to be greater than 16
- BIOS has RAM waitstate and ISA clock divider selection
- no VLB, only 16-bit ISA slots
- no external cache
- internal cache seems to cover only the first 4MBs of RAM (that's what CACHECHK reports)
- 25/33/40 MHz CPU clock options
- CPU seems to work well at 40MHz with zero-WS RAM
- mobo runs fine on a single 72-pin 16MB FPM stick
- even with just the on-chip cache, the U5 outperforms a typical 486 by about 20%
At 33MHz cache is 67.4 MB/s and RAM 30.6 MB/s (0WS), and at 40MHz it goes up to 81.0 MB/s / 36.7 MB/s