z/OS Communications Server V2R1 | PSERVIC operand of the MODEENT macroinstruction

Associated with each terminal is a default logon mode table entry. Within this entry, the primary and alternate screen sizes are specified, and a code that describes how these screen sizes are used.

In the MODEENT macroinstruction, the 11th byte of the PSERVIC can have the value of X'03' (PSERVIC=X'....................03..'). When this field is specified as X'03', the primary screen size is 24x80, and the alternate screen size is determined by the device. TSO/VTAM queries the device to determine the alternate screen size.

In the MODEENT macroinstruction, the 2nd and 11th bytes of the PSERVIC can have the value of (PSERVIC=X'..80..................00..') for a device with extended data stream capability. When these fields are specified, the primary screen size and the alternate screen size are determined by the device. TSO/VTAM queries the device to determine the primary and the alternate screen sizes.

You do not have to code different logon mode table entries for TSO users when the only difference is the screen size. Users logging on to TSO with a screen size different from the default do not have to specify a logon mode table entry. The screen size is determined dynamically.

Note: The 3274 Terminal Controller must be Release 65, or higher, or the logon fails.

Code the 12 bytes of device-specific hexadecimal data of the PSERVIC operand as described in Table 1.

Table 1. Coding the device-specific hexadecimal data of PSERVIC
Hexadecimal code	Related device
`X'00..00000000..........00'`	For non-SNA (LU0)
`X'02..00000000..........00'`	For SNA (LU2)
`X'..00....................'`	Device without extended data stream capability
`X'..80....................'`	Device with extended data stream capability
`X'............0000000001..'`	Buffer size 480 only (12x40)
`X'............0000000002..'`	Buffer size 1920 only (24x80)
`X'............0C280C507F..'`	Buffer sizes 480 or 960 (12x40 or 12x80)
`X'............185020507F..'`	Buffer sizes 1920 or 2560 (24x80 or 32x80)
`X'............18502B507F..'`	For buffer sizes 1920 or 3440 (24x80 or 43x80)
`X'............18501B847F..'`	For buffer sizes 1920 or 3564 (24x80 or 27x132)
`X'............18503EA07F..'`	Buffer size 9920 only (62x160)
`X'............0000000003..'`	Primary buffer size 1920 only (24x80). If a device is extended data stream capable (see above), TSO/VTAM queries the device to determine the alternate size.

To prevent switching of screen sizes on a device that has more than one size possible, code the screen size you want in the primary area of PSERVIC and a X'7E', which means no switching. Following is an example:

PSERVIC=X'............1B8400007E..' For 3564 buffer only.

For details on coding the PSERVIC operand for your particular device, see your component description.

For details of the bit settings in the PSERVIC operand that represent bytes 13 - 24 of the session parameters, see z/OS Communications Server: SNA Programming.