Are file formats different between RSX-11M and RT-11? If I get one of the PDPs up and running I need to sort out the 40-50 disk packs that should be a mixture of RT and RSX. There's a boot pack labeled for the 11/24 but it will be a surprise as to which OS boots. I think there's an RK07 pack for the 11/34A and I understand from the previous owner that RSX had been the OS running on it. If there's some version dependancy involved, the RSX boot disk pack is probably 4.x and if the 11/24 pack is RT, it is *possibly* v3.x. There's an even bigger batch of 9-track tapes. ~75 or so hangin' on the tape rack. But, I think most of those could be backup tapes or development files from Moog Hydropoint machine tools (Moog made computer controlled machine tools) according to what I see in the rather cryptic contents of the labels. I gotta get the rack w/TS03 and TS11 subsystem lashed up to the 11/24 or 11/34A (whichever I get running first) to check them out. Will an RL01 pack be readable in an RL02 drive? Thanks again, Chris -- -- Christian Fandt, Electronic/Electrical Historian Jamestown, NY USA Member of Antique Wireless Association URL: http://www.ggw.org/freenet/a/awa/