APUT81
         PLA
         STA   RETADR     ; LOCAL RETURN ADDRESS STORAGE
         PLA              ; BECAUSE OF CALLING AGET81
         STA   RETADR+1
         PLA
         STA   :AIDX
         STA   :IDX
         DEC   :AIDX
         DEC   :IDX
         PLA
         STA   ADDR4      ; ARRAY ADDRESS; USES ADDR4
                          ; ADDR1
         PLA
         STA   ADDR4+1
         PLA
         STA   ADDR3      ; ADDRESS OF DATA TO BE
         PLA
         STA   ADDR3+1
         LDY   #0
         LDA   (ADDR4),Y
         STA   :ASIZE
         LDY   #1
         LDA   (ADDR4),Y
         STA   :ESIZE
         STA   :ESIZEBAK
         LDA   ERRCTRL
         CMP   #1
         BEQ   :CHKERR
         JMP   :ERREND
:CHKERR
         LDA   :IDX             ; IF IDX > ARRAY LENGTH
         CLC
         ADC   #1
         CMP   :ASIZE
         BCS   :OVF
         JMP   :ERREND
:OVF
         _ERR  :E_SID;:E_OVF1;:E_DUMP;:ESIZE;#9
:ERREND
         LDY   #0
         LDA   #0
         STY   SCRATCH
         STY   SCRATCH+1
         BEQ   :ENTLPA
:DOADD
         CLC
         ADC   :AIDX
         TAX
         TYA
         ADC   SCRATCH
         TAY
         TXA
:LPA
         ASL   :AIDX
         ROL   SCRATCH
:ENTLPA
         LSR   :ESIZE
         BCS   :DOADD
         BNE   :LPA
         STX   :IDX
         STY   :IDX+1
         CLC
         LDA   #2
         ADC   :IDX
         STA   :RES
         LDA   #0
         ADC   :IDX+1
         STA   :RES+1
         CLC
         LDA   :RES
         ADC   ADDR4
         STA   :RES
         LDA   :RES+1
         ADC   ADDR4+1
         STA   :RES+1
         STA   ADDR2+1
         LDA   :RES
         STA   ADDR2
:LP
         LDA   (ADDR3),Y
         STA   (ADDR2),Y
         INY
         CPY   :ESIZEBAK
         BNE   :LP
         LDA   RETADR+1
         PHA
         LDA   RETADR
         PHA
         LDX   ADDR2+1
         LDY   ADDR2
         LDA   :ESIZE
         RTS
:ESIZE   DS    1
:ESIZEBAK DS   1
:ASIZE   DS    1
:AIDX    DS    2
:IDX     DS    2
:RES     DS    2
:E_SID   ASC   "APUT81 (PUT81 MACRO)",00
:E_DUMP  ASC   "DUMPING :ESIZE(1) :ESIZEBAK(1) :ASIZE(1)"
         ASC   ":AIDX(2) :IDX(2) :RES(2)",00
:E_OVF1  ASC   "OUT OF BOUNDS! INDEX > ARRAY LENGTH",00