There is "MB815AT REV: 1.0" printed on the PCB right next to the AGP slot. Nothing else except some jumper instructions.
I googled String "MB815AT" and "M815AT", found some Chinese and Russian sites about PC-Chips MB815AT(Under their local brand names, with the same support site
www.pcchips.com.tw). The layout and the color is quite the same with my mobo.
To my disappointment, no entry concerning the mobo in question was found at pcchips web site. Clue lost.
P.S. I am quite confused by the relationship among ECS, PC-Chips and T&W Electronics.