SUMMARY: Problem with SunOS 4.1.3 and Toshiba CDROM

From: Mike Jewison (
Date: Thu Mar 11 1993 - 02:49:01 CST

Sorry for the delay in posting the summary; I've been busy. My problem:

> We have a SparcStation 1 which is set up as a dataless client. The SS1
> also has a Toshiba CDROM plugged into the SCSI port. Under SunOS 4.1.1
> (which was installed by someone else years ago) the CDROM worked fine,
> although we couldn't boot from it (no big deal).
> I upgraded the machine to SunOS 4.1.3 last week, and since then whenever
> we try to mount the CDROM we've been getting error messages like:

    [Error messages removed for brevity]

> I expect the problem lies with something not being configured correctly
> in the kernel, but I've checked the 4.1.3 installation with the old
> 4.1.1, and can't see where any changes may have been previously made.
> I should note that I borrowed a Sun CDROM from someone else in the
> building and it works like charm.
> Any insights gratefully accepted.

Apparently this is something which rears its ugly head every so often.

It appears that my problem is as a result of the fact that the Sun
CDROM defaults to a 512 byte buffer; the Toshiba defaults to 2kb.
The Toshiba CDROM was therefore sending larger buffers than the
Sparc 1 could handle, hence the data overruns.

Two people send me a short C routine to modify the buffer size on the
Toshiba to 512 bytes, but I was unable to get it working successfully
(although to be honest I didn't try too hard). Several others suggested I
contact the vendor from whom we originally purchased the CDROM (Young Minds).
I have done this and a driver patch for SunOS 4.1.3 is winging its way to
me even as I type. Hopefully.

Thanks to all who responded:

David Galloway
Geert Jan de Groot
Peter D. Bille
Bob Hayes
Kevin Sheehan
Perry Hutchison

- Mike Jewison, Systems Manager
  Space Astrophysics Laboratory
  Institute for Space and Terrestrial Science
  4850 Keele St., 2nd Floor
  North York, Ontario
  CANADA   M3J 3K1

Internet: Phone: (416) 665-5451 FAX: (416) 665-5497

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