Using the HCD to Define the Manual Tape Library

The mere application of the MTL code onto a system — without an IPL or activate — enables the ability to define MTL UCBs. You specify the MTL keyword, in conjunction with the LIBRARY-ID and LIBPORT-ID keywords, to define the UCB as MTL resident. Figure 1 is an example of the Define Device Parameters / Features panel.

Figure 1. Define Device Parameters / Features

                     Define Device Parameters / Features
                                                                  Row 1 of 9
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 Specify or revise the values below.

 Configuration ID . : MVS1
 Device number  . . : 0960         Number of devices  : 1
 Device type  . . . : 3590

 Parameter/
 Feature     Value    P Req.  Description
 OFFLINE     No               Device considered online or offline at IPL
 DYNAMIC     Yes              Device supports dynamic configuration
 LOCANY      Yes              UCB can reside in 31 bit storage
 LIBRARY     No               Device supports auto tape library
 MTL         Yes              MTL resident device
 AUTOSWITCH  No               Device is automatically switchable
 LIBRARY-ID  12345            5 digit library serial number
 LIBPORT-ID  01               2 digit library string ID (port number)
 SHARABLE    No               Device is Sharable between systems
  F1=Help        F2=Split       F3=Exit        F4=Prompt      F5=Reset
  F7=Backward    F8=Forward     F9=Swap       F12=Cancel     F22=Command

Invoke the Hardware Configuration Definition (HCD) facility.
Select the Define Device Parameters / Features panel
Specify MTL keyword, Yes
Specify LIBRARY-ID, observing the following rules:
1. Values are arbitrary, five-digit, hexadecimal values
2. Values cannot be all zeroes
3. Values must be unique among libraries, MTL or ATL
4. Values must be unique among systems that share TCDBs
5. Values must correspond with values specified in the SCDS
6. Devices attached to the same control unit cannot span control units within the same MTL
  For example, given a physical string of four 3590-E11s, two of the drives on this control unit can be defined to one MTL and the second two to another MTL. Or, each drive can be defined to a different MTL.
Specify LIBPORT-ID, observing the following rules:
1. Values must be arbitrary, two-digit, hexadecimal values
2. Values cannot be all zeroes
3. Values Identify all devices attached to a specific control unit in a given library. Because LIBPORT-IDs map to control units, all devices on a given control unit must have the same LIBPORT-ID.
4. The number of devices with a given LIBPORT-ID must not exceed 16.

If the IODF resulting from this definition can be shared with systems that have no MTL support installed, or that have the full-function code installed but they are in coexistence mode (MTLSHARE has been specified in the LOADxx member), then the drives on MTL-defined UCBs will be defined as standalone (non-ATLDS) drives.