<This evening I accidentally aquired a PDP-11/23 (model # 11E23-FE). It <has RD-52A hard disk and dual floppies like the ones on a Rainbow. sounds like a BA23 with a PDP-11/23 in it. There are many varients of the 11/23 cpu and you need a handle number and boot page info. <What can I do with it? It does boot and is running RT11 with 512k of ram. First off it's a computer, you can do whatever computers do. More ram? By PDP-11 standard 512k is quite enough to be very useful and even a large system. More memory is in the form of boards assuming the is space in the backplane for it. <It appears to have a fault. It often runs for just a few minutes then <drops to a @ prompt and starts spitting out strings of ? marks endlessly. <Is this a failure anyone is familiar with? How can I tack more ram on it? May be a problem with the terminal not the PDP-11. Some terminal emulators if hit with the wrong stuff will spew crap. The PDP-11 you have likely has halt on BREAK enabled. <The machine is is fairly good condition and appears complete. -- While you supplied only a cursory description, it sounds like a nice machine. Allison