Life with S-100 boxes is a bit more complicated. Machines rarely kept their original factory configuration... and it was not uncommon to find every board in the machine made by a different company. With Compupro stuff, there are 5 main lines: 1. "Disk n" disk controllers, n=1, 1A, 1B, 2, 3, or 4. 2. "CPU nn" CPU cards, nn=85/88, Z, etc. 3. "Interfacer n" I/O boards, n=1 to 4 4. "System Support" boards, with real time clock, console port, etc. 5. "RAM nn" boards, nn usually greater than 16. There are many other less common Compupro boards, like their video controllers, etc. Of course, there were literally *thousands* of S-100 manufacturers, and the above list only helps if you know you're dealing with Compupro stuff. Well, then, these are your disk controller(s). The "something" that comes after Disk is very important in identifying them! The "512K" sounds like a Compupro board etch identifier, but I just looked over my Compupro Disk 1's, 1A's, Disk 2's, and Disk 3's, and none of them say 512K. Maybe it's a Disk 1B? Disk 4? What makes you think that it's the 8" drive interface? Look for the 50-pin cable coming from the drive box and figure out where it's going. 32 6116's gives you 64Kbytes, a comfortable amount for running CP/M-80. Your description matches that of the Compupro RAM17, though lots of of other manufacturers made similar boards that might be in your system. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927