Anthony Clifton said: Sorry, I'm just back from a vacation trip and I'm still not back at work yet, so I'm doing this from memory. It been at least a year since I sent that disk, but I seem to remember that I sent you an email after I sent the disk saying something like "Oops, by the way, by mistake the NSDOS disk I sent you is a special version compiled to load at 0100 hex not the normal 2000 hex." Look at the label, if this is the case it should say North Star DOS (version something) AT 100. So (if this is the case) you would need RAM starting from 0000, and BASIC on this disk would expect to find the DOS I/O vectors starting from 0100 hex, but the BASIC programs would work with the normal version of DOS. Without being able to search through my old email, because I'm not at work, thats how I remember it. Sorry, I just seems to have gotten in a hurry and sent the wrong DOS on the disk without thinking. I run CP/M also so I just naturally start RAM at 0000. I hope I'm not thinking of someone else I sent NSDOS to. I'm glad you're having so much success. --Doug ==================================================== Doug Coward dcoward(a)pressstart.com (work) Sr. Software Eng. mranalog(a)home.com (home) Press Start Inc. http://www.pressstart.com Sunnyvale,CA Curator Museum of Personal Computing Machinery http://www.best.com/~dcoward/museum/ and the new Analog Computer Museum and history Center http://www.best.com/~dcoward/analog ====================================================