[SunRescue] About Sun3 and SCSI

[jwbirdsa at carfallin.picarefy.com]

>>I'd replaced them all with Sun-2 units...
>
>...which are dreadly slow and not supported under NetBSD.

   That's why I want somebody to write a driver already. I haven't noticed
any real performance difference between the two: they're both slow.

>James: Do you wanna trade? I have 4 Sun-2 SCSI controllers   
>and i'd love to have 4 Sun-3 SCSI controllers...

   There's a place around here that has a stack of VME SCSI controllers,
probably Sun-3 but I'm not sure. $10 each, last time I checked. They
also had a bunch of other VME stuff, mostly Network Coprocessors and
Prestoserve boards.

>>SCSI allows for plenty of expansion, but it's pretty much plug-and-pray.
>
>I've got a feeling for what works and what's going on...
>And most SCSI problems have a simple solution: It's the cable!

   Or the disk or controller are slowly going bad, or they don't
negotiate backward very well, or maybe it's just the VME bus being
flaky, or the driver isn't very good because nobody cares about the big
VME crates anymore, or...

   SCSI has a lot of promise, but for sheer ease of use, just about
anything else is better. SCSI has all the issues that other busses do
with devices not playing nice together and such and then a whole lot
more all its own. I don't think I've ever had a situation, on any kind
of machine, where I was able to plug a second device into the bus and
have it just work, and all too often even the first one requires a lot
of futzing and hope.

   --James B.