Hi Chris I spent quite a bit of time looking at the stuff from the web site on the CPM-8000. It looks like the CPM.SYS in the cpm8k11 stuff is built specifically for the M20. It was made with the symbol table so I was able to find the various tables. I don't think the fellow that did this implementation really had a solid grasp of a boot process but what they have done should work. There is no reason why what they call CPMLDR.SYS couldn't have been a slightly modified CPM.SYS with a simple loader added ( like more traditional CPM's ). If you look, you'll see that in one place ( I forget where ), they have a compiler flag called TRANSFER. It would seem that they had, in fact, connected a 8 inch drive to a system as the next drive after the hard drive. They used this as a transfer system. The disk, that the .img files were from, was built as though it were for this setup. It was not a bootable disk. There is quite a bit of information on building a boot disk in the various files that contain the tables T0S0, T1S0 and T1S1. These are the main information involved in creating a boot disk. My understanding of T0S0 leads me to think that the one they have is not correct but may have still worked. I believe we can continue to just use the unaltered T0S0 that is on the disk, formatted by the M20. We can just build the bootable image on one of these disk. We don't need to get too carried away. Once we've built a disk that boots, we can add one file at a time to a different disk and transfer them using the second drive. This way, we only have to deal with the directory on the CPM for one file at a time. This simplifies transfers but may take a little extra time. Still, we wouldn't have to deal all that much with disk space allocation. I'm going to fiddle with trying to build up an image but I'll only be able to do this in the evenings this week. Next weekend I'll be off visiting relatives. I converted another RAM board to 128K. It now boots to 384K :) It was one of the two B/W memory boards that I have. It wasn't as simple as I thought. Changing pin 8 Pin 9 had connections inside to an internal power plane. This time, rather than lifting a pin on the chips, I lifted one of the socket pins. I used a little quick setting epoxy to insulate the board pin 9 from the socket pin that I bent out to the side. On these boards, there was at least, a nice jumper hole to connect this additional wire to ( it even looks like they had intended it to be jumper configured but the internal plane connections kept one from doing that ). It took me about 4 hours to do one board. I could have done it faster if I didn't want to save the IC's. Just clipping the IC out and pulling the pins is a lot faster than removing the entire IC, intact. It is a lot safer for the board but I just can destroy working chips. Anyway, do you know of any issues that I should look out for in creating a boot disk from these files? I haven't seen anything that looks like a show stopper. Dwight