donn@CS.UTAH.EDU (Donn Seeley) (04/23/87)
We have two RP07 disk drives left over from a decommissioned DEC-20 installation which we'd like to use on our VAX 8600. Unfortunately the EVRAC formatter won't format these disks on the 8600 -- it dies with an invalid map register error in the massbus adapter status register when it attempts to format the last cylinder of either RP07. We were forced to format instead on a VAX 11/750 (apparently EVRAC can produce non-interleaved format on the 750, since no multi-sector transfers are attempted). This went fine, but when we put the RP07s back on the 8600, we still had trouble. Some 20%-40% of writes earn an invalid map register error; this disappears after 1 to 6 retries, however, so all the writes eventually succeed, just very slowly. DEC field service has no idea what might be going on, although they've been quite cooperative. Some more clues: I reformatted all but the last cylinder of one RP07 on the 8600, and this didn't seem to have any effect on invalid map register errors on that drive. I can copy data from a different drive to one of the RP07s treating it as raw/foreign empty space, and I don't get any errors. If I write sectors in random locations on an RP07, using lots of seeks, I see 20%-40% of writes fail in the usual way. There appears to be no pattern to the cylinder/track/sector information for writes that fail. We have an RP06 and dual TU78s on the same massbus; we have no problems formatting or writing the RP06 or accessing the TU78s, and the RP07s behave the same way if these devices are removed from the massbus. I have never seen an actual drive error from either RP07. The massbus adapter gets a clean bill of health from EVCAA; the RP07s pass every standard test of EVRHA except #30, which fails with a massbus adapter invalid map register error. The diagnostics are all at current revision levels. The RP07s are correctly strapped for non-interleaved operation and the formatter was told to expect non-interleaved format. For what it's worth, the 8600 ordinarily runs 4.3 BSD Unix, and we sometimes boot VMS 4.3 from the RP06 for diagnostics. Is there anyone out there who's successfully using RP07s on an 8600? I'm eager to hear how this can be done. Donn Seeley University of Utah CS Dept donn@cs.utah.edu 40 46' 6"N 111 50' 34"W (801) 581-5668 utah-cs!donn