POP     LD      R1,EMPTY         ; EMPTY <-- -3FFF
        ADD     R2,R6,R1
        BRz     Failure
        LDR     R0,R6,#0
        ADD     R6,R6,#-1
        AND     R5,R5,#0
        RET
Failure AND     R5,R5,#0
        ADD     R5,R5,#1
        RET
EMPTY   .FILL   xC001