Template:360 Assembly/Example 95

For the purpose of this example it is assumed that R14 is equated to 14, R15 is equated to 15 etc., to provide cross reference - see EQU Assembler pseudo-instruction)

* some typical assembler instructions showing comments to the right
        L     R15,=A(MOVE)                    Load sub-routine address into R15                   
        BALR  R14,R15                         Go to the sub-routine ===>
*                                             ....return here with return code in R15
*
*****************************************
*  Move the input to output             *
*****************************************
MOVE    EQU   *                               Start of a sub-routine called "Move"
        USING *,R15                           Tell the assembler reg. 15 points to
*                                             this address 
        MVC   OUTPUT,INPUT                    Move the input to the output area 
        SR    R15,R15                         Clear register contents (set Return code = 0)
        BR    R14                             return to caller
        DROP  R15                             Tell assembler we are no longer using
*                                             register 15 and resume using previous register
*
TABLE   DC    C'ABCDEFGHIJKLMNOPQRSTUVWXYZ'   Table of letters of the alphabet
INPUT   DS    Cl80                            Input area
OUTPUT  DS    Cl80                            Output area