Yes, That is also a very good question. The memory sticks used are specifiec to these boards. As far as I know Bally used 3-4 diff. manuf. of these. Look at the one you have now and try to match it Exactly. Patriot made some that would work as well on these. I know of a few members that bought some 1gb sticks and they would not work in the past. Since I had/have a pile of these I just pulled one out of my others to double-up to 2gb but I do know the patriots with the exact specs to your orginal will work. ****Looked at a few others here, Transcend,unigen,Patriot. Transcend and unigen more common in the ones from the factory that I see here-Just have to be exact spec wise and they will work.