The absolute simplest method I know of is to put a WTO somewhere within the assembler code.
For example, I have stuck the following at an arbitrary point in the middle of the ARSUSECX code:
WTO 'Ed Arnold ' Write To Operator
WTO 'says that ' Write To Operator
WTO 'YOU ARE IN ' Write To Operator
WTO 'ARSUSEX1 ' Write To Operator
WTO 'RIGHT NOW ' Write To Operator
I stuck it right in the middle of the inits:
INIT200 DC 0H'0'
WTO 'Ed Arnold ' Write To Operator
WTO 'says that ' Write To Operator
WTO 'YOU ARE IN ' Write To Operator
WTO 'ARSUSEX1 ' Write To Operator
WTO 'RIGHT NOW ' Write To Operator
LA R0,WKSIZE(,0) Load the workarea length
and you get in the SYSLOG:
STC02415 00000010 Ed Arnold
STC02415 00000010 says that
STC02415 00000010 YOU ARE IN
STC02415 00000010 ARSUSEX1
STC02415 00000010 RIGHT NOW
Yeah, it looks hokey, but it's quick and easy.