Starting TSO/VTAM time-sharing

Use the START command to start TSO once VTAM® is active. This command creates the terminal control address space (TCAS), which accepts requests by terminal users for logon to TSO.

 
S membername[.identifier][,devicetype|,[/]devnum]
       [,volumeserial][([,MEMBER={name|nn}][,USERMAX=nnnnn]
           [,GNAME=[name | NONE])]
               [,keyword=option[,keyword=option]...]

The parameters are:

membername: The name of the member that contains the source JCL for the started task. The member can be a cataloged procedure (for example, residing in SYS1.PROCLIB) or a job that starts TSO/VTAM time-sharing. Many installations use TCAS as the membername.
identifier: The user-determined name identifying this specific time-sharing session. If you omit an identifier, the system automatically uses the job name as the identifier.
devicetype: The device type of an output device where time-sharing parameters from SYS1.PARMLIB are listed. This operand is useful only if the PRINTOUT DD statement of the cataloged procedure invoked by the START command specifies DDNAME=IEFRDER. If the PRINTOUT DD statement specifies a SYSOUT device, the parameter values are listed on that device.
Note: devicetype and devnum are mutually exclusive.
[/]devnum: The device number of an output device where time-sharing parameters from SYS1.PARMLIB are listed. A device number is 3 or 4 hexadecimal digits. A slash (/) must precede a 4-digit number and is optional before a 3-digit number.
Note: devicetype and devnum are mutually exclusive.
volumeserial: If devicetype is a tape or direct access device, the volume serial number of the volume mounted on the device.
MEMBER=name: The name of the member in Parmlib that contains TSO/VTAM time-sharing parameters.
MEMBER=nn: A two-digit decimal number that forms the suffix for specifying the name of the member in Parmlib that contains TSO/VTAM time-sharing parameters, where the name has the form TSOKEYnn.
USERMAX=nnnnn: The maximum number (0 to 32,767) of users that can be logged on to TSO/VTAM time-sharing at any one time. If USERMAX is not specified here or in the parmlib member that contains TSO/VTAM time-sharing parameters, a value of 40 is used.
GNAME=name: The generic resource name for TSO/VTAM to use while operating in a sysplex environment. You may specify this keyword only when TSO/VTAM is operating within a sysplex.
GNAME=NONE: Specifies that TSO/VTAM will not use a generic resource name. If you specify this value on the START command, the system will ignore any GNAME value in the TSOKEY00 parmlib member.
keyword=option: Any appropriate keyword specified to override the corresponding parameter in the cataloged procedure. The maximum length of each keyword=option is 66 characters. No individual value within this field may be longer than 44 characters in length. If you are overriding a symbolic parameter, do not use any of the DD keywords. For example, do not use UNIT= to override the device type positional parameter in the cataloged procedure.

If more than one Parmlib name is specified, or if no name is specified, the order of priorities that determines which time-sharing parameters are used is:

The member name coded on the PARMLIB DD statement.
The MEMBER operand of the START command.
The keyword operand of the START command.
The default member TSOKEY00 if a member is not specified but a Parmlib (that contains TSOKEY00) is.
The default values in the TCAS program if neither a member nor a parmlib is specified.