I've got a long story about the TU45 SUP/SUS TUP/TUS servo adjustments which required three hands (or two hands and your fly open) and a pair of TU45's at Fort Monmouth which caught fire during said servo adjustments. (I was the unfortunate tech who volunteered for TU45 tape training when all the others ran away to hide). The TU45 was damned close to the worst tape drive DEC ever shipped for reliability (my teacher at DEC training said the TU10 was probably a worse design -- his comment was a tape drive designed by the team that brought you the RK05. It was a crew that had no tape experience and one that put the tape head in the location with the highest amount of tape flutter.). The TU45 reengineering set Pertec back years because they supposedly had to strip their engineering talent off the TU77 work that was near completion to get the DEC engineering folks off their butts on the TU45. The TU45 was the first vacuum column design by Pertec and had all the problems of a first design... It was basically a tension arm design which was revamped to use vacuum columns... It had the reliablity and uptime from hell. The 36 bit community and Vax folks found this stopgap drive was keeping them from getting their backups done and was less solid than the TU/TE16's that were slow but reliable. Big KL sites used the TU72 (STC drives)... Small ones had TE/TU16's and TU45's -- DEC pushed TU45->77 swapouts in the field to cut the workload on Field Service on these dogs. --Bill (not a tape specialist -- although I subbed for one often and even got one call on a KL on a TU45 -- which had me have the 36 bit tech run the diags for me...) -- bpechter(a)monmouth.com | FreeBSD since 1.0.2, Linux since 0.99.10 | Unix Sys Admin since Sys V/BSD 4.2 | Windows System Administration: "Magical Misery Tour"