I think you're right. I've been using it with an Atari 4MB wingboard wheras I used to use the Atari 14MB board. The 4MB is more stable, very rarely needs reset to boot up and also works if the bus is overclocked. I hear that the Atari 14MB ones load the bus too much, it certainly has a lot of DRAM chips! I've been looking out for one that takes 72 pin simm.