On Sat, 29 Jan 2000, der Mouse wrote:

> If I tell the last drive on the chain to terminate,
> it works fine.  If I tell both drives to disable their terminators and
> then slap an external (active) terminator on the end of the cable, I
> get the behavior I described.
> 
> Personally I suspect something relating to the terminator-power SCSI
> pin,

Yes, Sun3/60's short termpwr to ground, unless you modify them with some
wire snippers.  I remember reading that somewhere--maybe you did, too.  I
hope not, or the rest of this message will be boring.

Anyway Seagate drives have that messy ``Power from drive, Power To Bus,''
three-way two-jumper sideways-backwards-chicken nonsense, so they kind of
bypass this problem by powering their resistors off the power supply
rather than the SCSI bus, sometimes.  However, if your drives worked when
terminating themselves, then you very likely blew their termpwr ``to-bus''
fuses, both of 'em :) :(.  If so, even after you correct the Sun3
short-of-death, you still won't have termpwr.  Maybe you have one of those
handy active terminators with the LED on it that tells you if there's
termpwr?

I think there are docs for snipping that stupid Sun-3/60 pin-of-death on
the picarefy hardware reference faq.  It is typically an operation
performed on the VME board between the connector and the board, IIRC. But
when the surgery is all over, you still need to get a device besides the
Sun3 to supply termpwr.

-- 
Miles Nordin / v:+1 720 841-8308 fax:+1 530 579-8680
555 Bryant Street PMB 182 / Palo Alto, CA 94301-1700 / US