.code

stack   START   0

	LDA   #9
   	STA   @stackptr
   	JSUB  stackpush     . PUSHA

  	JSUB  stackpop      . POPA
	LDA   @stackptr

halt    J       halt


stackinit
        STA     stacktmp       

        LDA     #STACK          
        STA     stackptr       

        LDA     stacktmp        
        RSUB


stackpush
        STA     stacktmp        

        LDA     stackptr
        ADD     #3              
        STA     stackptr

        LDA     stacktmp        
        RSUB


stackpop
        STA     stacktmp        

        LDA     stackptr
        SUB     #3              
        STA     stackptr

        LDA     stacktmp        
        RSUB


.data

stackptr    WORD    0

stacktmp    WORD    0

STACKSIZE   EQU     50          
STACK       RESW    STACKSIZE

        END     stack