HELLO CSECT The name of this program is 'HELLO'
* Register 15 points here on entry from OPSYS or caller.
STM 14,12,12(13) Save registers 14,15, and 0 thru 12 in caller's Save area
LR 12,15 Set up base register with program's entry point address
USING HELLO,12 Tell assembler which register we are using for pgm. base
LA 15,SAVE Now Point at our own save area
ST 15,8(13) Set forward chain
ST 13,4(15) Set back chain
LR 13,15 Set R13 to address of new save area
* -end of housekeeping (similar for most programs) -
WTO 'Hello World' Write To Operator (Operating System macro)
*
L 13,4(13) restore address to caller-provided save area
XC 8(4,13),8(13) Clear forward chain
LM 14,12,12(13) Restore registers as on entry
DROP 12 The opposite of 'USING'
SR 15,15 Set register 15 to 0 so that the return code (R15) is Zero
BR 14 Return to caller
*
SAVE DS 18F Define 18 fullwords to save calling program registers
END HELLO This is the end of the program