Subject: Re: Performa 550 / Zip disk driver
To: B. Alex King III <king@sunphy1.phy.uic.edu>
From: Bob Nestor <rnestor@metronet.com>
List: port-mac68k
Date: 03/06/1997 18:35:40
>I have been following this topic with some interest as I am trying to run 
>NetBSD from a Jaz cartridge and have a few questions.  Does all of what has 
>been said here apply to Jaz carts. too?  I used Silverlining to partition 
>the cartridge and now have some minor conflicts similar to those 
>described here.  Also, the partitioning software will allow me to install 
>the Silverlining driver on the Driver_43 partition.  How will the disk 
>drivers on the Driver and Driver_43 partitions interact?  Thanks for the 
>help.

Under MacOS the DRIVER Partition contents, if used, are for systems that 
are not capable of running SCSI-Manager 4.3.  For systems which are 
SCSI-Manager 4.3 compliant, the driver in the DRIVER_43 partition might 
be used.  Which disk driver is actually loaded depends on the Startup 
Disk setting in PRAM, that is if you've specified disk "0", the SCSI 
driver is pulled in from that drive on boot and used for all disks in the 
SCSI chain.  The drivers on any other disks in the chain are usually 
ignored from this point on.  I discovered this the hard way when I was 
working on the "mkfs" code to zap MacOS partitions into NetBSD types. In 
this case you get a real heart thumping Sad Mac with Death Chimes on boot 
which is *very* difficult to get past!

Under NetBSD the disk drivers are part of the Kernel and the contents of 
the disk DRIVER partitions are ignored, although the first driver 
partition is usually mapped to BSD disk slot "d".

-bob