[comp.unix.aux] SCSI devices under A/UX

liam@cs.qmw.ac.uk (William Roberts) (03/12/90)

In article <235@inpnms.UUCP> logan@inpnms.UUCP (Jim Logan) writes:
>Maybe I can get the ball rolling in this newsgroup with a simple
>question.  Can anyone tell me how painful it is to use disk drives
>and QIC tape drives from other vendors under A/UX?

>I don't know if the A/UX SCSI driver will support any old big
>SCSI disk I plug in.  Does the format program know how to format
>a disk this large?  ...   Can I boot from this
>external 300MB drive?  Can I leave the Finder on my 40MB internal
>drive so I can use it sometimes?

Disk drives are OK, but they will need to be partitioned in a
way that conforms to the Apple partitioning approach, and then
some extra A/UX stuff done with the A/UX dp utility. Your best
bet is to stick with a disk that is advertised as being
suitable for use with the Macintosh (but then these are pretty
cheap anyway, compared with Sun peripherals and the like).

Any Mac-compatible disk that doesn't require special things in the
System Folder should work, and so do some of the ones that do. The
SCSI handling under A/UX is more or less generic SCSI commands
and the A/UX system understands big disks just like other UNIX
systems do.

You *must* keep the Finder somewhere since you can only boot
A/UX by running a Mac application called "sash" = StandAlone Shell.
You can have A/UX and the little MacOS partition you'll require
on any of the disks, and you can mix and match to your heart's
content. A/UX understands the notion of dividing disks into
serveral distinct partitions (as does MacOS these days).

>Does the SCSI tape driver know how to talk to
>anything besides the Apple 40MB tape drive?

Tape drives I know nothing about...


-- 

William Roberts                 ARPA: liam@cs.qmw.ac.uk
Queen Mary & Westfield College  UUCP: liam@qmw-cs.UUCP
Mile End Road                   AppleLink: UK0087
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dixon@sagittarius.crd.ge.com (walt dixon) (03/13/90)

In response to a question about what devices the A/UX SCSI driver will
support,  William Roberts write:

>Disk drives are OK, but they will need to be partitioned in a
>way that conforms to the Apple partitioning approach, and then
>some extra A/UX stuff done with the A/UX dp utility. Your best
>bet is to stick with a disk that is advertised as being
>suitable for use with the Macintosh (but then these are pretty
>cheap anyway, compared with Sun peripherals and the like).
>
>Any Mac-compatible disk that doesn't require special things in the
>System Folder should work, and so do some of the ones that do. The
>SCSI handling under A/UX is more or less generic SCSI commands
>and the A/UX system understands big disks just like other UNIX
>systems do.

A word of caution is in order here.  If one is using the drive solely
for A/UX,  the generic SCSI driver works fine,  but one may run into
problems with a MacOS partition.  Before Jasmine came out with support
for A/UX (they do support A/UX now,  don't they?),  I moved A/UX to
a Jasmine DD140 drive (creating a 40MB mac partition and increasing the
size of the root A/UX file system.  Using the generic SCSI driver
A/UX worked flawlessly,  but the MacOS hung during disk writes.  After
some digging,  I traced the probem to SCSI write blind commands.
By converting write blind requests to write,  I eliminated the MacOS
write problem.

Walt Dixon		{arpa:		dixon@crd.ge.com	}
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Walt Dixon dixon@crd.ge.com