I recently acquired an Everex Systems EV-138 Memory Board. I am going to try to use it to boost my system to more than 640K of RAM. It has three banks, 2 with 64kx1 modules, 1 with 256Kx1 module. What I will do is to remove one of the 64Kx1 modules and replace the other 64Kx1 with a 256Kx1 module. With some fiddling of the motherboard's switches and the Everex's jumpers, it should work.