All; I've made a bit of progress in my quest, having serendipitously acquired a DEC M7522 card (RUX50: RX50 for Unibus) as part of a pile-of-parts. It has two obvious problems. 1. A 0.6"-wide 40-pin socketed DIP that is top-center on the board has been trashed (literally, the top scraped off and the die exposed!). (The socketed 82S105 just below it mid-board is just fine.) The ruined chip appears to be a CPU; what is it really? Maybe a T-11? (The FD1796 is somewhat to its right -- midway to the Berg connector, soldered-down, and looks just fine!) 2. A pair of 0.6"-wide 28-pin socketed (presumed) EPROMs (mid-left on the board, next to a pair of HM6264P-15) are missing. What are/were these (type, speed)? The board otherwise looks absolutely perfect, excepting damage to some of the handles. I'm still having no luck finding any documentation for this board; a printset is especially desired. I throw myself onto the good graces of the community to examine that M7522 card that you have in your system (or on your shelf) in order to verify what the apparent-CPU is/was, the EPROM-type/speed (2764? 150ns?), and to either point me to a copy of the EPROM contents for the chip-pair or graciously offer to extract a copy of yours :->. I'd be happy to send some blanks if you have the means to make copies. A quality scan of an intact board would be a helpful start on the chips. Thank you, very much! paul