[comp.lang.asm370] job number

RCOPROB@HDETUD1.BITNET (Rob van Hoboken +31 15 78-3813) (07/18/89)

How about looking in the SSIB (subsystem Identification block) pointed to
by JSCBSSIB.  JSCB (Job Step Control Block) is anchored by TCBJSCB.
The field you're looking for is called SSIBJBID, the macro is called IEFJSSIB.