Hi all. Things are progressing nicely. The core board is tested and works. I get the monitor prompt on the VT220 terminal connected to the RS-232 interface. That means there is also software for it. Go to the updated page http://home.hetnet.nl/~tshaj/pdpsite/homebrew/startframe.html Next steps are: 1) adjust monitor software so it runs without the RAM 5565 chip 2) build the I/O ports interface board 3) write the "low-level" in- and output routines 4) write the "stand-alone" pattern SW (the Cylon-eye on the DATA LEDs) 5) the real work: interface with Ersatz-11 (..John?) The monitor software (e11-6802.zip) already contains some SW but that has not yet ran; it just assembles without errors ... - Henk.