diff --git a/src/SUDOKU.MAC b/src/SUDOKU.MAC
index 558e150..e71fda5 100644
--- a/src/SUDOKU.MAC
+++ b/src/SUDOKU.MAC
@@ -1,2 +1,32 @@
 		TITLE    SUDOKU SOLVER
+P=17                                   ;Defines AC 17 as the stack pointer.
 
+A=1                                    ;Define two accumulators
+B=2                                    ;A and B
+CHTTYO==1                              ;Output channel number
+
+PDLLEN==100                            ;Length of push down stack
+PDL:    BLOCK PDLLEN                   ;Storage for push down stack
+
+START:  MOVE P,[-PDLLEN,,PDL-1]        ;Initialize the stack
+        .CALL [SETZ ? SIXBIT/OPEN/     ;Open the TTY channels
+		    [.UAI,,CHTTYO] ? [SIXBIT/TTY/] ((SETZ))]
+		 .LOSE %LSFIL
+
+
+L:      HRRI A, HELLO                  ;Load the address of the string into A
+        PUSHJ P, OUTSTR                ;Print the string.
+		JRST L                         ;Keep looping
+
+;Subroutine to output the ASCIZ which starts in the word
+;whose address is in A. Clobbers A.
+OUTSTR: HRLI A, 440700                ;Make A into a byte pointer to fetch a string
+OUTST1: ILDB B, A                     ;Fetch the next character of string into B
+        JUMPE B, CPOPJ                ;If it is the terminator, return
+	    .IOT CHTTYO,B                 ;Else output the character
+		JRST OUTST1                   ;and loop around.
+
+CPOPJ:  POPJ P,                       ;Return
+
+HELLO:  ASCIZ /HELLO WORLD/
+        END    START