On Sun, Feb 3, 2013 at 9:05 PM, Rick Murphy <rick at rickmurphy.net> wrote: I would agree. I don't have any experience with RL02s on OS/8, but I have an RL8A and an RL01 that got a *lot* of use in the 1980s. According to the DEC "OS/8 Device Extensions User's Guide" (AA-D319A-TA, an update to the "OS/8 Handbook" - DEC-S8-OSHBA-A-D ) with the RL01, there are several binary handlers - RLSY.BN, RL0.BN, RL1.BN, RL2.BN, RL3.BN and RLC.BN. Presumably there's a similar scheme for the RL02. With the RL01, there was an 'A' and a 'B' partition at 2MB each, then the "leftover" blocks in each track made up the 1MB 'C' partition. I'm guessing here (since there isn't a lot of documentation on the RL02 under OS/8 to check my assumptions) that R2Ax-R2Dx are all equal size and about 2MB each. If you have handlers like RL20.BN and RL21.BN, where did they come from? I think you mentioned an RK05 pack that you started from? Have you diffed an octal dump of the handlers? Presumably they should be different at some small but key point to select drive 0 vs drive 1. I'm about to relocate a bunch of my PDP-8 stuff from long-term storage to a more convenient place. Part of what's there is my old DataSystems desk and my -8/A with the RL8A. That should make it possible for me to try out RL02s on that system for the first time (when I got it, the RL8A was $600, and an RL01 was about $150, but an RL02 was still over $2000). I didn't do so much that I ever "needed" more than a few MB (and it was soooo much better than a floppy-only system). I wish I had something specific to suggest. I'm following this thread with some fascination because I will probably be in the place you are at now sometime soon. -ethan