
Dear SCO Customer,

Support Level Supplement xnx102 is only necessary if you are trying to
configure multiple Mountain tape drives with SCO XENIX Operating
System Release 2.3.1, or 2.3.2.  If you are simply configuring a
single Mountain tape drive, the device driver is already available
in your system and all you need to do is type:

            /etc/mkdev tape

and follow the instructions for adding a tape drive in Chapter 16
of your SCO Installation and Maintenance Guide. 

The default settings for the Mountain tape controller board for
DMA channel, interrupt channel and Base Address are:

                                                           XENIX
                    DMA     Interrupt      Base         Controller
   Board          Channel    Vector       Address          Type
====================================================================
 Mountain QIC-02     1         3            28cH            5


Be aware that the default setting for the Mountain controller board
uses interrupt 3, which is the same interrupt used by Com 2.  If you
have a Com 2 port, you must set the tape controller for a different
interrupt (2, 4, or 5).  Interrupt 4 is used by Com 1 and interrupt 5
is used by lp2.  If you use interrupt 2 you should indicate that the
interrupt is "25" when you run "mkdev tape". 

Insert your tape controller board and follow the instructions below.

1.    Run the SCO XENIX install program by typing "/etc/install" at a
      superuser prompt.  The following prompt will be displayed:

                First Floppy (y/n)

      Insert the SCO XENIX Mountain tape driver diskette and answer 
      "y" (yes) to the above prompt.

      When the install process is done, a "mkdev tape" command will
      automatically be issued.

2.    Once the "mkdev tape" command is issued, select "1 Install
      Cartridge Tape Driver" from the first menu.

      If you have changed the base address, DMA or interrupt channel
      settings on your tape controller board, select "2 Modify
      tape parameters" from the second menu, and modify the
      appropriate parameters.

      If you haven't changed any board settings, or you are finished
      modifying parameters, select "1 Display tape parameters" from
      the second menu, and verify that the tape parameters are correct.
      
      Once you have verified the tape parameters, select "q" (for
      quit) at the second menu.  Select "q" again at the first menu. 
      Answer "y" to the question, "Do you wish to create a new kernel now?"
      Answer "y" to the question, "Do you want this kernel to boot
      by default?"  You'll then be prompted for more floppy diskettes.
      Answer "n" to this prompt.


3.    Now you should reboot your system to run the new kernel.
      During the booting process, the streaming cartridge
      tape and associated parameters will be identified on
      your boot screen.

      If you need to change the DMA, Interrupt or Base Address settings
      you need to physically move jumpers or switches on the tape
      controller board.

      Use the Mountain SETBOARD program (PC-DOS) to identify which
      jumpers or switches you need to move.  Note that the "XENIX
      Controller Type" number shown above is different from the number
      used for the type of controller board for the SETBOARD program
      (refer to Appendix B of your Tape Software User's Guide to
      identify your controller type for SETBOARD).  Once the changes
      have been made  and the board is installed, you must also use
      the XENIX "mkdev tape" program to "Modify tape parameters."


4.    To confirm that there are no interrupt or base address
      conflicts between your tape system and other devices in your
      computer system, issue the following commands as a test:

                tape reset
                tape rewind
                tape status

      The tape should be rewound after the tape rewind command.
      After the tape status command, the following should be
      displayed:

                     status:   beginning-of-tape
                soft errors:   0
                  underruns:   0

      If your system hangs instead of displaying the status, this
      means there are conflicts in either the interrupt channel
      or base address.  Such conflicts must be resolved by changing
      the interrupt or base address as described in step 3, before
      going on to step 5. 


5.    You may now exercise your Mountain tape unit.
      This command copies the "/etc" directory from the hard disk
      to the tape drive:

                tar cvf /dev/rct0 /etc

      This command lists the files written to tape by the previous
      example:

                tar tvf /dev/rct0

      This command  restores the "/etc" directory from the tape
      drive to the hard disk:

                tar xvf /dev/rct0


6.    Creation of Multiple Tape Devices
      =================================

      You will need to create multiple tape devices if you are configuring
      your system for multiple Mountain tape drives.

      Use the "/etc/mknod" command to make your desired tape devices.
      The following is an example device for one tape drive in QIC-24
      format that rewinds:

         /etc/mknod /dev/rct0 c 10 0

      "rct0" is the name of the sample tape device.  The letter "c"
      should always be included.  The major number for tape devices
      is always 10.  The minor number is a decimal number that
      represents the following 8 bits (HI true):

                bit 0 = 1st tape drive on-line
                bit 1 = 2nd tape drive on-line
                bit 2 = 3rd tape drive on-line
                bit 3 = don't rewind tape following tape close
                bit 4 = select format (0 = QIC 24, 1 = QIC 11)*
                bit 5 = 4th tape drive on-line
                bit 6 = increase memory allocation**
                bit 7 = set maintenance mode

      *   only QIC 24 is supported on Mountain boards
      **  increases buffer allocation for tape driver, so operations
          will be performed faster

      (For information about converting binary numbers to decimal,
      see the last page of these instructions.)

      If bits 0, 1, 2 and 5 are off, as in the example above, the
      1st drive will be the active drive.

      As an example of a tape device for two tape drives with
      increased buffer allocation and no-rewind, the "mknod" minor
      number would be:

                01001011 = 75

      This would be used as:

                /etc/mknod /dev/nrctb12 c 10 75

      Note that since there is no-rewind for the above device, an
      operation performed after this device is used will start at
      the point on the tape where the "nrctb12" device stopped.

      The following is an example of a tape device for four tape
      drives:

                /etc/mknod /dev/rct1234 c 10 39

      The following is an example of a tape device for two tape
      drives with no-rewind after tape close:

                /etc/mknod /dev/nrct12 c 10 11

      The following is an example of a tape device for two tape
      drives that does rewind after tape close:

                /etc/mknod /dev/rct12 c 10 3

      As an example of how no-rewind and rewinding tape devices
      can be used, the following example backs up three volumes on
      a two-drive tape system:

                tar cvf /dev/nrct12 /etc
                tar cvf /dev/nrct12 /usr
                tar cvf /dev/rct12 /bin

      After the first volume is backed up onto the first tape, the
      tape will halt.  The second tar command will back up the
      second volume from that location on the tape on.  If the
      volumes are larger than the first tape, the backup will be
      continued onto the tape in the second drive.  The third tar
      command will back up the third volume and then rewind the
      current tape.

      If you wanted to list the files in the above tape volumes,
      in a similar manner you'd use the following commands:

                tar tvf /dev/nrct12 /etc
                tar tvf /dev/nrct12 /usr
                tar tvf /dev/rct12 /bin

      Note that another item in this database presents a more thorough
      treatment of no-rewind devices.


           Converting Binary Numbers to Decimal
           ====================================

                        Binary to Decimal Table

                            00000001 =   1
                            00000010 =   2
                            00000100 =   4
                            00001000 =   8
                            00010000 =  16
                            00100000 =  32
                            01000000 =  64
                            10000000 = 128

      In the earlier example for "nrctb12", the bits that make up the
      minor number for dev/nrctb12 are 01001011.

      If you add up the decimal values for the desired factors (two drives,
      no-rewind, increased memory allocation), the total is 75: 

           1st tape drive:     00000001 =  1
           2nd tape drive:     00000010 =  2
           no-rewind           00001000 =  8
           increased memory    01000000 = 64
                               --------  ---
                               01001011   75


If you have any questions, please call our Customer Services Department
at (800) 626 - 4381.  SCO Customer Service is available Monday through
Friday, 6:00 A.M. to 5:00 P.M., Pacific Standard Time.

We appreciate your business.

SCO SoftCare Support Services

