[comp.sys.next] FIX for problems booting from hard disk when PLI floppy is attached

juan@bitnerd.ogi.edu (05/14/91)

References: <1991May9.165912.1042@bitnerd.uucp>
Reply-To: apple.com!bitnerd!juan (Juan Pineda)

I posted an article about a week ago describing problems with booting after I  
connected a PLI floppy to my NeXT cube.  I submitted a bug report to NeXT, and  
they sent me a reply within a few days.  I'm posting their reply since it may  
be useful to other purchasers of PLI floppies, or other owners of cubes with HP  
disk drives.

I've abbreviated the bug report, but it went something like this:

"I've got a NeXT cube 68030 that I have upgraded to a 68040.  The cube has a  
factory installed OD and 660MB HP drive.  I'm running 2.0 extended.  I've also  
got a PLI Superfloppy that I've attached as SCSI device #4.

The problem is that when I connect the PLI SCSI floppy, the system tries to  
boot off of the floppy instead of the hard disk.

It would appear that when the PLI drive is connected, the ROM is choosing to  
boot the system before it can see the HP drive, and so it boots from the PLI,  
which it can see.  I've asked PLI about this, and they say that there is  
nothing in their drive that would cause this behavior."

Tech support at NeXT wrote back within a few days with this response:

"To really fix the problem:

Remove the jumper on the HP 660 drive that causes the drive to spin-up when  
powered on, it will wait for a spin-up command to be sent to it after it  
responds to the target id request. This seems to fix the problem with the  
system trying to boot on the floppy drive.

The jumper is the 4th one from the right as you face to Back of the HP drive.  
You can remove this jumper by opening the back of the cube, there is a dual  
line of 9 pins, between the power socket and the SCSI ribbon cable connecter.
If the drive is target 1, the first jumper on the right should have a jumper.  
There is also a jumper on the set 5th from the right, this is the parity  
enable. Leave the 1st and the 5th jumpers  on. Only remove the jumper on the  
4th set of pins from the right."

I performed the recommended procedure, and my system boots just fine now. :-)

I must point out that I was quite impressed with the quickness and completeness  
of the response that I received from NeXT technical support.  I've dealt with  
them on a number of problems, and from my contact with them I'd have to say  
they're doing a great job.
--
Juan Pineda
juan@apple.com
-- 
Juan Pineda