pack@acdpyr.ucar.edu (Dan Packman) (01/09/90)
In article <9510@batcomputer.tn.cornell.edu> eric@geology.tn.cornell.edu writes: >We are contemplating the purchase of an Exabyte 8mm tape drive >for our system. There is a choice about whether to connect it >to our VMS MicroVAX II (Q-bus) or to our DECstation 3100. In a similar vein, we have an old VAX 8300 with both unibus and BI bus. What are the relative performance hits with the uni-bus version of an 8mm unit versus a unibus version? Dan Packman NCAR INTERNET: pack@ncar.UCAR.EDU (303) 497-1427 P.O. Box 3000 CSNET: pack@ncar.CSNET Boulder, CO 80307 DECNET SPAN: 9.367::PACK
grr@cbmvax.commodore.com (George Robbins) (01/09/90)
In article <5939@ncar.ucar.edu> pack@acdpyr.UCAR.EDU (Dan Packman) writes: > In article <9510@batcomputer.tn.cornell.edu> > eric@geology.tn.cornell.edu writes: > >We are contemplating the purchase of an Exabyte 8mm tape drive > >for our system. There is a choice about whether to connect it > >to our VMS MicroVAX II (Q-bus) or to our DECstation 3100. > > In a similar vein, we have an old VAX 8300 with both unibus and > BI bus. What are the relative performance hits with the uni-bus > version of an 8mm unit versus a unibus version? The main issue is that you have perhaps one vendor for the BI version (Megatape?) and n-vendors for Q-bus/Unibus applications. For this incarnation, I don't think that any of the busses are going to have performance problems. The most important thing is to get a commitment from the manufacturer and/or distributor that the thing works with Ultrix and they they will make it work if it doesn't or if it stops working with Ultrix x.y. The main market still seems to be VMS and you may find Ultrix tech support to be minimal... Somone else asked about generic SCSI for Unibus/Q-bus machines. I've been looking for a while and never found anything. Just about all the SCSI boards have some kind of imbedded MSCP/TMSCP emulation and none see to offer any generic or passthru mode. Maybe the reference issue of one of the Unix rags and a lot of phone calls would turn something up. I'd like to be able to hook up a cluster of 6 or so CD-ROM drives to one of my systems, but it doesn't look like there's any way to do this except perhaps with some DS3100 as a server... -- George Robbins - now working for, uucp: {uunet|pyramid|rutgers}!cbmvax!grr but no way officially representing arpa: cbmvax!grr@uunet.uu.net Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)