Subject: Re: LC 475
To: None <port-mac68k@NetBSD.ORG>
From: J.C.Highfield <J.C.Highfield@lut.ac.uk>
List: port-mac68k
Date: 10/17/1995 23:27:36
> >For some reason I get the feeling someone should write a netbsd/mac68k
> >formatter. Then I get the feeling it would be only sort of worth it. 

I had a look at doing this and decided it really wasn't worth it unless
the APS formatter was no longer available from the ftp sites....

> actually, what are we really needing?  Most disk drives are already shipped
> with some software that will put the basic scsi driver and partitions on a
> drive.

If we could grab the drivers that are already on the drive then writing a
NetBSD/mac68k (re)formatter might be practical. One problem is that there
tends to be driver/partition-layout specific information in some places for
the driver to read.

> Writing a little program to muck with partitions (creating, deleting) would
> be rather easy to do.  The difficult parts of a writing a "formatter" would
> be actually doing a low level scsi format, and the generic scsi driver needed
> for the disk (although there is a driver in the rom, i dont know what the
> on disk driver is used for)

The "low level scsi format" is a single SCSI command! I wrote a disk
initialiser for my Quantum LT730S which turned out to be easier than I
expected. The bit that takes too much time and effort is writing the 
SCSI driver that should be written onto the disk. The driver in the
Mac's ROM is supposedly a generic (and presumably low-performance) one
intended to be used just during booting.

For my experiments I hijacked the driver from Apple's HD SC Setup, which
is hardly an acceptable choice for a general distribution formatter. Apple
provides sample code for a SCSI driver, but the documentation states that
the code is unliscensable and that they expect you to write your own. To
write and particularly to test a SCSI driver would be a *major* effort even
if loosely based on that sample code.

> --chas iii

Regards,
        Julian