PDP-11/93 and PMI Memory

Well, I was finally able to get a PMI memory board to expand my 11/93 to the full 4 Meg. (Thanks Paul!) I thought it would be as simple as configuring what bank I wanted it to fill and inserting it (in front of the CPU). Sadly, that didn't work. First problem is the only document i could find is not for the actual version of the board I have. It has the same switch sets so I tried it anyway. Set it to be in the upper 2Meg and gave it the next CSR after the on board memory. No luck. 11/93 still reports 1024KWords and the Map command shows neither the additional memory or the second memory CSR. Anybody have any experience with this? Is there a switch I have to change on the CPU module to make it recognize the additional external memory? IS there something about PMI that I am missing? Any advice gratefully appreciated. bill