Your motherboard is either going to be an Asus A7N8X, A7N8X-X, or A7N8X-VM.
The VM has onboard video, but if it is this board the video connector is near the serial port.
It's probably the A7N8X or A7N8X-X. The difference between the two is the -X is a single channel DDR memory board and the non-X is dual channel. On the -X all the memory slots are black, and on the non-X one of the slots is blue.