Board revision: 1.01
BIOS version: 1001 (02/16/2005)
As you can see, the little board and socket that normally would appear between the x16 PCIe connectors is missing; instead, Asus has placed there a couple of electrical components. Switching from single mode to SLI mode can be done in software; all you need to do is select the desired mode in the BIOS or using Asus' AI Selector tool.
The A8N-SLI Premium should be in the shelves like this.