The MA520 was a redesign of the MA512, using 64K DRAMs and 2732 EPROMs. It also fixed the problem that the MA512 consumed a block of 16 I/O ports even though it only actually used two. (That was awful if you wanted to use four or eight of the things for color.) I found a scan of the MA512 manual, but nothing on either the MA520 or the palette card. Does anyone have them? AutoCAD-80 apparently supported the Microangelo cards: http://www.fourmilab.ch/autofile/www/chapter2_14.html Does anyone still have a copy of that, or any other interesting software that uses the Microangelo? Thanks, Eric