.include "labmac.i"
         .section .text
         .globl main

main:    JSR Qinit

         MOVE.L #1, D0
         JSR QInsert
         MOVE.L #2, D0
         JSR QInsert
         MOVE.L #3, D0
         JSR QInsert

         JSR QDelete
         MOVE.L D0, D1
         JSR outint
         JSR QDelete
         MOVE.L D0, D1
         JSR outint
         JSR QDelete
         MOVE.L D0, D1
         JSR outint

         RTS

  | ---------------------

         buflen = 10
buffer:  DS.L buflen

Qinit:   LEA buffer+4, A5      | initialize HEAD (start empty)
         LEA buffer, A6        | initialize TAIL
         RTS

QInsert: SUB.L #4, A5          | decrement HEAD
         CMP.L #buffer, A5     | check HEAD underflow
         BGE InOK
         ADD.L #(buflen*4), A5 | put HEAD to end of queue
InOK:    MOVE.L D0, (A5)       | write data in queue
         RTS

QDelete: MOVE.L (A6), D0       | return TAIL element in D0
         SUB.L #4, A6          | decrement TAIL
         CMP.L #buffer, A6     | check TAIL underflow
         BGE DelOK
         ADD.L #(buflen*4), A6
DelOK:   RTS

  | ---------------------


outint: MOVEM.L D1-D2/A0,-(SP)  | SAVE REGISTERS
        MOVE.L	#intstr+10, A0  | pointer A0 behind last digit

loop:   DIVUL.L #10, D2:D1      | D1 := D1/10, D2 := remainder
        ADD.B   #'0', D2        | make D2 digit character
        MOVE.B  D2, -(A0)       | write digit
        TST.L   D1              | check quotient
        BNE	loop                | while ? 0 repeat with quotient in D1 

print:  CALLEXEC LCD_PutString  | call string print (address in A0)
        MOVEM.L (SP)+,D1-D2/A0  | RESTORE REGISTERS
        RTS

intstr: .asciz "1234567890 "	| number can have up to 10 digits