z/OS User Exits › z/OS Blockmode User Exits—TSO › TIRDEVT—Device Characteristics Exit › Source Code

Source Code

TIRDEVT exit is written in IBM Macro Assembly so it can use system service calls that are not available through COBOL.

On entry, register 1 addresses an OS-standard argument list, consisting of five arguments. These are as follows:

1. Address of emulated IO-PCB.
2. Address of emulated ALT-IO-PCB.
3. Address of the device capabilities information data area to be modified by this exit and returned to the caller.
4. The address of an 8-byte field containing the name of the current dialect.
5. GLOBDATA