musicus@mit-dspg@mit-mc (02/22/83)
I am trying to configure a new VAX 11/750 system for use in our research group at MIT, and am trying to resolve some thorny equipment issues. a) How well do the 6250 bpi, 125 ips tape drives work in reality? Will backup dumps go much faster than on a 1600 bpi, 125 ips drive? Tar's? Anyone own a TU77 or TU78 and have any comments on their reliability? b) I've been told that Berkeley UNIX does not support 2 UBA's. Why? Is this due to laziness, or is there a fundamental problem? c) How does Berkeley UNIX cope with bad spots on Winchester drives? In particular, what about an RM80, or a Fujitsu Eagle with Emulex or System Industries controllers? Anyone hear of Tecstor drives? Any experience with Ampex Capricorn drives? d) DEC's early manuals on the VAX family supplied lots of information about the microprogram option for the 750. The latest manual states uncategorically that DEC provides no assistance for user microprogramming. Is this true? Does this mean that the microprogramming option for the 750 is worthless except for the special floating point modes? e) The best disk drive deal from DEC is for the RA60/80/81 family. Unfortunately, the controller for these is on the UNIBUS, so that one UNIBUS will end up being dedicated to the disks. All other UNIBUS devices probably must get stuck on the second UBA. Has anyone found this to be a problem? Thanks, Bruce Musicus musicus@mit-mc