Hi, This is for Walt Ezyk, regarding memory for am IBM Blue Lightning DX4/75 board-based system. YOu need the 72-pin SIMMs, True parity, capable of fast-paging mode. I don't have their address or E-mail handy, but you can definitely get them from, Shenandoah Memory Systems. I believe they are in Vienna, or Falls Church, Virginia, USA. They use name-brand memory chips, fully tested, and guaranteed, no cheap stuff. Note, they won't quote you the rock-bottom price either, but nobody will beat their quality or their guarantee. They have a toll-free number good all over the U.S., and they send a representative to many of the big regular week-end computer "shows" all over the eastern half of the country. If my memory serves me correctly, that board has four SIMM sockets. You can put any size of single-sided SIMMs in each of the four slots, or use two double-sided SIMM modules, leaving alternate sockets empty. With single-sided, 16MB 32-bit full, true parity, SIMMs, you max out at 64MB of RAM. With 2 32MB double-sided modules, you max out at 64MB. With 2 8MB double-sided modules, you max out at 16MB. With four 4MB single-sided modules, you get your 16MB. The board is picky. Forget about using non-parity memory modules, or ones that use parity emulation. The Blue Lightning board doesn't like them. Reply to: [log in to unmask] Brent Reynolds, Atlanta, GA USA Ask not for whom the bell tolls; let the machine get it. Net-Tamer V 1.11.2 - Registered Curious about the people moderating your messages? Visit our staff web site: http://nospin.com/pc/staff.html