SCSI trouble on a MicroVAX IIGPX

From: Iggy Drougge <optimus_at_canit.se>
Date: Fri Feb 9 21:22:04 2001

On Fri, 9 Feb 2001, ajp166 wrote:

> From: Iggy Drougge <optimus_at_canit.se>
>
> >First of all, what the hell is MSCP? =)
>
> MSCP, Mass Storage Control Protocal. Unlike PCs VAX storage
> controllers are very smart and do part of the work independant
> of the interface to the media. It allows a MFM , EIDE or SCSI disk
> to look and work the same to the OS.

Doesn't it on all platforms? I'm not certain about PC circumstances,
though. =)

> >And why does it suddenly boot from the network, when it previously
> booted from
> >the hard drive at the sole mention of "boot"?
>
> Well, there is nothing to forget in the MVII, no cmos like PCs. The boot
> sequence is look on the bus for MSCP disk(s) and try to boot each, if
> that
> fails try to boot via network, if that fails look for a rom board and try
> to boot that.

Then the HD must have disappeared as far as the VAX is concerned.

> If it's failing to find the SCSI board/drive (likely if it tried the net)
> then you either
> put the card in the wrong place or the cables on wrong. Q-bus, unlike
> PCs,
> has a serial ordered bus grant and interrupt structure. That means if
> the
> chain is broken all the devices down the line from the break will not be
> seen.
> The only critical devices are disks, NIC and serial ports.

I inserted the card in the same slot it was in before removal, but could
it have been inserted the wrong way?
I don't suppose it would matter on which connector on the SCSI cable that
the RZ55 was connected?

> >BTW, does this mean that the II GPX could boot over MOP, or even TFTP?
>
> MOP, yes. TFTP no.

Great.

> Actually MVII is a fairly simple machine.

Hm, that depends on your background. ^_^;;
Received on Fri Feb 09 2001 - 21:22:04 GMT