i dont know who manufactured the card, but its clearly a tnt2 m64. sorry to tell you but that card is crap..... i guess if you are currently using an 8 mb sis card, it would be an improvement, but they sell for around 25.00. im not trying to let you down - free is always good. its just a well documented poor performer.
It's a scaled down version of the version of the TNT2, kind of the way the Geforce 2 MX is to the Geforce 2 GTS. The M64 has only about 1/2 the speed of the the TNT2. Usually it only came with 8mb or 16mb of memory which further limits it. It's probably only suitable for 3D games at 640x480 due speed and memory limitations.