The SUPRBDOS program as modified by Benjamin Ho has always looked interesting to me, but I've never been able to get it to work on my system. I've finally succeeded, and perhaps my experiences will be able to help someone else. NOTES: 1. On the Northstar Advantage, the SYSGEN does not take a file as an argument, so standard Kaypro installation can't be used. Manual installation is required with some minor modifications. 2. On the Northstar Advantage, the is DF00. The SYSGEN image is at 1D00. The offset thus is 3E00. Most users should be able to find their corresponding addresses using the guide found in SUPRDOS2.LBR. SYMPTOMS of the original installation which didn't work: 1. All CCP functions worked fine (DIR, TYPE, ERA, SAVE, USER) including functions that took a file as an argument. 2. Any attempt at running a file from disk (STAT, PIP, etc) fell into a black hole. The MODIFICATIONS that finally did the trick: 1. Modify the range of bdos that gets filled with zeroes. WAS: f 0 IS: f 0 2. Carefully note the serial number and patch back in after having overlayed the SYSGEN image with DOS.HEX. The final steps in their exact sequence were: 1. Create a one line ORG.DAT. Specifically: org 0df00h 2. Create the file DOS.HEX using Z80MR on DOS.AZM & DOS?.MAC 3. A>sysgen SOURCE DRIVE NAME (OR RETURN TO SKIP): 1 DESTINATION DRIVE NAME (RETURN TO REBOOT): 4. A>ddt (original DDT only, *not* DDTZ) -f1D00 2AFF 0 (note! 2AFF not 2B00) -iDOS.HEX (per the original instructions) -r3E00 (per the original instructions) -s1D00 (note! repatch the serial # back in) 00 01 00 02 00 03 etc, etc, etc -^C (exit DDT) 5. A>sysgen SOURCE DRIVE NAME (OR RETURN TO SKIP): DESTINATION DRIVE NAME (RETURN TO REBOOT): 1 Hope this helps. Russell Gaspari, Los Angeles, 9/23/87.