Dear SCO Customer,

Support Level Supplement (SLS) ptf7421c, the UnixWare 7.1.0 vtoc and
disksetup Supplement, contains modifications to address all of the
issues included below.

SLS ptf7421a addressed this issue:

1.  The BIOS disk geometry for a second disk is ignored and always set
    to 64 heads and 32 sectors.

    To demonstrate this:

      - Find the parameters for the second disk from the boot prompt 
        using 'show HDPARM1'.

      - Add the second disk using diskadd(1M).

      - Display the disk parameters using 'prtvtoc -p /dev/rdsk/...'.

    Note that the parameters displayed are different from those displayed 
    at boot.

SLS ptf7421b addressed this issue:

2.  It is not possible to read or make filesystems on hard disks, or 
    optical disks, with a sector size greater than 512 bytes.

SLS ptf7421c additionally addresses this issue:

3.  A potential kernel address fault in sd01 is fixed.

SLS ptf7421c applies to all supported disk drive types (such as SCSI, IDE,
as well as others).


Contents
--------

        /etc/conf/pack.d/vtoc/Driver.o
        /usr/sbin/disksetup


Software Notes and Recommendations
----------------------------------

SLS ptf7421c should only be installed on: 

        UnixWare 7 Release 7.1.0


Installation Instructions
-------------------------

1. Download the ptf7421c.Z file to the /tmp directory on your machine.

2. As root, uncompress the file and add the SLS package to your system
   using these commands:

        $ su
        Password: <type your root password>
        # uncompress /tmp/ptf7421c.Z
        # pkgadd -d /tmp/ptf7421c
        # rm /tmp/ptf7421c

   Alternatively, this SLS package may be installed in quiet mode,
   that is, without displaying the release notes and asking for
   installation confirmation.  To do this, use these commands:
 
        $ su
        Password: <type your root password>
        # uncompress /tmp/ptf7421c.Z
        # pkgadd -qd /tmp/ptf7421c all
        # rm /tmp/ptf7421c

3. Reboot the system after installing this SLS package.

The release notes displayed prior to installation can be found in:

        /var/sadm/pkg/ptf7421/install/ptf7421.txt


Removal Instructions
--------------------

1. As root, remove the SLS package using these commands:

        $ su
        Password: <type your root password>
        # pkgrm ptf7421

2. Reboot the system after removing this SLS package.

If you have questions regarding this SLS, or the product on which 
it is installed, please contact your software supplier.