Dear JMW, The Boomerang uses 30-pin, non-parity, 120ns or faster SIMM's. Check out www.marketpro.com or www.pricewatch.com for the nearest computer show or for inexpensive prices respectively. You can save quite a bit, because 30-pin SIMMs are not really in use any more, and to be honest 72-pin SIMMs are nearly in the same boat, now! Hope this helps! Tchus, Lee-ohki.