Ok, so another clue discovered: 1) Typing DX1:/Z "zeros" the directory on a floppy. 2) Trying this on drive 1 leaves the floppy scrambled, doing it on drive 0 seems to work. Trying DX0:A=DX1:MONITR.SYS/O does not write the boot block A disk formatted and zeroed is not mbootable. Since the source to FORMAT was included I thought I'd take a peek. It tells the controller that is embedded in the drive "format that disk." and it does. There is a slim changce I've got a "spare" 8" drive that I can use to check the alignment on my drive 1. Are all 8" drives the same on their connector? (actually there are the NEC drives in the Chrislin box that aren't being used at the moment. What the heck is used for "delete" on RT-11? backspace doesn't work nor does DEL apparently. If anyone remembers how to actually assemble something I'd appreciate it. WHen I run assembl it gives a '*' prompt, to which I can type DX0:SAMPLE.MAC and it will assemble it except that it doesn't recognize any of the macro definitions because it apparently hasn't included "SYSTEM.MLM" or whatever it is. --Chuck