NSC Qbus memory module

Hi all, I'm looking for information on a National Semiconductor memory module for Qbus PDP-11s. It is marked with 980110014-221 REV-E. I've uploaded a photo of it here: http://www.cosam.org/images/nsc4m.jpg I know it's a 4Mbyte (or thereabouts) card and it works fine with the KDJ11-A (11/73) it came with. It however won't work with a KDJ11-B (11/83) I picked up recently - the onboard diagnostic LEDs report 53, which corresponds to memory address 0. The KDJ11-B does however work fine with a MSV11-P. There are plenty of jumpers and wire wrap posts on the NSC board but, as it's always worked in its original configuration, I've never needed to figure out what the all did. Any documentation or pointers much appreciated. Then again: if anyone's got some PMI memory boards they don't need, I'm all ears! Cheers, -- Steve Maddison http://www.cosam.org/