Hi newcomer and welcome to the Tom's hardware forum.
Yeah, U can install only 1GB stick, but you won't see a big performance, the recommended RAM today is 4GB or more. Even more, if you are running a x64 bits OS or Win vista or Win 7.
One stick is NOT getting me to post, the processor might be bad. I didn't want to spend more money on extra ram 'till I tested this used mobo out first, so I was hoping I could get it fired up with just one stick ! Thanks, Ian.