[SunRescue] Proper use of VME scsi controllers?????

[jwbirdsa at carfallin.picarefy.com]

>Ah, but I have a sun2 501-1006 adapter in a Multibus-VME adapter and 9U
>frame!  Maybe that's why I never got it to work under SunOS-4!  :-)

   That's a new one on me. I've never seen one or seen it listed in a FEH,
so I assumed it had never been done. This always seems to be a bad
assumption with Sun stuff. :)

>The only problems I've ever heard about anyone having with the sun3
>controller are under older versions of NetBSD where DMA either didn't
>work, or wasn't reliable.

   Even under SunOS, they had a regrettable tendency to make the entire
machine lock up hard. Different controllers, CPUs, chassis, disks...
nothing seemed to solve the problem. Maybe I just have the worst luck in
the world, but in my own experience the only si's that I have seen working
properly are the onboard ones in 3/50's and 3/60's, which are rock solid.
   The si support NetBSD/sparc 1.4 is nonfunctional. I went through the
code and fixed it enough that the kernel could get through device
enumeration, but then it went off into the weeds after that anyway, so I
gave up. In NetBSD/sun3 1.4, you just get bunches of timeouts and "stuck
busy", but it works well enough that it may take a few months before the
filesystem damage becomes critical.

   The boot ROMs usually had to reset the sc a time or two before it would
boot, but thereafter it would run for months on end without a single error
or problem of any kind. None of my systems need more performance than the
sc can provide (if I needed speed, I wouldn't be running Sun-3's, after
all!), but they do need to run reliably for long periods.

   --James B.