PDP-11/73 questions

I found an OEM 11/73 at Salvage this morning. It was built by Netcom. I'm trying to identify a few boards that are in it. Wonder if anyone can help? There's a pair of double-width boards marked KHV1, one says "COMMS CHIPCARD", the other says "DMA CARD". The boards are connected by a wide ribbon cable. The latter has a handwritten tape label which says "Modified 422 / DTR tied active / provides xmit clks". I take this to mean this is some type of RS-422 interface, but can't find any notes about it online. The other item (two of them, actually, identical) has virtually no identifying markings. It's a quad width board, marked "(C) Orange, CA 92665". The reverse has a small icon of a whale, and says "MOEBI QUICK". There may be text under then handles, but they're essentially riveted onto the board. In the center of the back edge of the board, there's a wide ribbon cable connector. Multiport serial boards perhaps? I believe this was probably a Merit SCP machine (node CES1), for anyone who was around educational networking in Michigan over 15 years ago. There's a board in the machine which is definitely a custom item, marked "MFV (C) 1984 UMNET", which I'm sure was developed by the U of Michigan/Merit folks. The latter appears to have its own processor, EPROMs, etc. The other boards in the machine are the CPU, and a DEC 128k RAM board. Images (warning: LARGE, about 3 MB each) are at: http://yagi.h-net.msu.edu/img_1282.jpg (quad board) http://yagi.h-net.msu.edu/img_1284.jpg (double board, COMMS) http://yagi.h-net.msu.edu/img_1286.jpg (double board, DMA) Any assistance would be much appreciated. Dennis Boone