Zorro-III Problems

-----------------------------------------------------------------------------

  Problems with transfers when using 4091 SCSI-2 controller or other
  Zorro-III boards. Check for revision of Super Buster; the revision 9 chip
  had problems with Zorro-III bus arbitration. Revision 11 of the Super
  Buster fixed this problem. Note that this problem is not due to DMA
  transfers, but Zorro-III bus arbitration, so it is possible to see it with
  any Zorro-III board.

  Problems may be encountered with the A2091 or GVP Series II SCSI controller
  boards. To isolate this problem, check disk transfers to Chip RAM with a
  program like Diskspeed 4.2. This problem can be fixed by replacing PAL U209
  on the A3640 daughterboard with a revision 3 version.

  There can be a software component to these problems, also. Check that
  libs:68040.library is at least version 37.30. Note that due to the way
  the library version numbers are handled, version 37.4 is an earlier
  version. The later 37.30 library correctly handles Zorro-III transfers and
  mapping of Zorro-III boards (for instance, Commodore's SCSI drivers require
  that copyback caching be disabled during DMA, and this version of the
  library does that).