JMP   ARRAYS82X
*
*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=*
*                              *
* ARRAYS82.LIB                 *
*                              *
* AUTHOR:  NATHAN RIGGS        *
* CONTACT: NATHAN.RIGGS@       *
*          OUTLOOK.COM         *
*                              *
* VERSION: 0.1.2               *
* DATE:    30-OCT-2018         *
* ASSEMBLER: MERLIN 8 PRO      *
*                              *
* LICENSE: APACHE 2.0, WHERE   *
*  APPLICABLE. CODE INSPIRED   *
*  BY THE WORKS OF OTHERS MAY  *
*  FALL UNDER A DIFFERENT      *
*  LICENSE (NOTED IN ROUTINE). *
*                              *
* THIS IS A STANDARD LIBRARY   *
* FOR 8BIT, 2 DIMENSIONAL      *
* ARRAY MANIPULATION. ARRAYS   *
* ARE PRECEDED BY LENGTH AND   *
* INDEXING INFORMATION.        *
*                              *
*------------------------------*
*                              *
* LIST OF ROUTINES             *
*                              *
* DIM82 : DIM A 2D, 8BIT ARRAY *
* AGET82: GET ADDRESS OF ELEM  *
*         IN ARRAY AT X,Y      *
* APUT82: PUT CONTENTS OF ONE  *
*         ADDRESS INTO ARRAY   *
*         AT INDEX X,Y         *
*                              *
*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=*
*
*``````````````````````````````*
* DIM82 :: INIT 2D ARRAY       *
*-                            -*
* THIS SIMPLY CREATES A 1D     *
* ARRAY WITH THE DIM OF        *
* ARRAYX BY ARRAYY.            *
*-                            -*
* FIRST BYTE OF MEMORY USED    *
* HOLDS LENGTH OF X (ROWS);    *
* SECOND BYTE HOLDS LENGTH OF  *
* Y (COLUMNS); THIRD BYTE      *
* HOLDS LENGTH OF EACH ELEMENT *
*-                            -*
* CLOBBERS:                    *
*                              *
* FLAGS:  ????----  REG: AXYM  *
*-                            -*
* CYCLES: ???                  *
* SIZE:                        *
*-                            -*
* USAGE:                       *
*                              *
*   LDA #>$300 ; ARRAY ADDR    *
*   PHA                        *
*   LDA #<$300                 *
*   PHA                        *
*   LDA #4 ; X DIMENSION BOUND *
*   PHA                        *
*   LDA #4 ; Y DIMENSION BOUND *
*   PHA                        *
*   LDA #1 ; ELEMENT BYTESIZE  *
*   PHA                        *
*   JSR DIM82                  *
*-                            -*
* ENTRY                        *
*                              *
* TOP OF STACK                 *
*                              *
* LOW BYTE OF RETURN ADDRESS   *
* HI BYTE OF RETURN ADDRESS    *
* ELEMENT SIZE IN BYTES        *
* Y DIMENSION BOUNDARY         *
* X DIMENSION BOUNDARY         *
* ARRAY ADDRESS, LOW BYTE      *
* ARRAY ADDRESS, HIGH BYTE     *
*-                            -*
* EXIT                         *
*                              *
* TOP OF STACK                 *
*                              *
* LOW BYTE OF RETURN ADDRESS   *
* HI BYTE OF RETURN ADDRESS    *
*                              *
*   Y = ARRAY ADDRESS LO BYTE  *
*   X = ARRAY ADDRESS HI BYTE  *
*   A = CLOBBERED              *
*,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,*
*
DIM82
*
** SAVE RETURN ADDRESS
*
         PLA
         STA   RETADR
         PLA
         STA   RETADR+1
*
** GET PARAMETERS
*
         PLA
         STA   :MCAND     ; ELEMENT LENGTH
         PLA
         STA   :AYSIZE
         STA   :AYBAK
         PLA
         STA   :AXSIZE
         STA   :AXBAK
         PLA
         STA   ADDR1
         PLA
         STA   ADDR1+1
*
** LOOP THROUGH Y, CLEARING MEMORY
** FOR X BYTES TIMES ELEMENT SIZE,
** MOVING TO END OF LAST CLEAR
** UNTIL FINISHED
*
** MULTIPLY X AND Y
*
         LDA   #0
         TAY
         STY   SCRATCH
         BEQ   :ENTLP
*
:DOADD
         CLC
         ADC   :AXSIZE
         TAX
*
         TYA
         ADC   SCRATCH
         TAY
         TXA
*
:LP
         ASL   :AXSIZE
         ROL   SCRATCH
:ENTLP
         LSR   :AYSIZE
         BCS   :DOADD
         BNE   :LP
*
         STX   :MLIER
         STY   :MLIER+1
*
** NOW MULTIPLY BY LENGTH OF ELEMENTS
*
         LDA   #0
         STA   :PROD+2
         STA   :PROD+3
         LDX   #$10
:SHIFTR  LSR   :MLIER+1
         ROR   :MLIER
         BCC   :ROTR
         LDA   :PROD+2
         CLC
         ADC   :MCAND
         STA   :PROD+2
         LDA   :PROD+3
         ADC   :MCAND+1
:ROTR
         ROR
         STA   :PROD+3
         ROR   :PROD+2
         ROR   :PROD+1
         ROR   :PROD
         DEX
         BNE   :SHIFTR
*
         INC   :PROD      ; INCREASE BY 3
         INC   :PROD
         INC   :PROD
         LDX   :PROD
         LDY   :PROD+1
*
** NOW CLEAR MEMORY BLOCKS, WHOLE PAGES FIRST
*
         LDA   #$00       ; FILL VALUE
         LDX   :PROD+1    ; NOTE THAT THIS WON'T
                          ; GO BEYOND A 16BIT VALUE;
                          ; ANYTHING HIGHER THAN
                          ; 16BITS IS MORE THAN
                          ; THERE IS MEMORY IN A
                          ; STANDARD APPLE ][
         BEQ   :PART
         LDY   #0
:FULL
         STA   (ADDR1),Y
         INY
         BNE   :FULL
         INC   ADDR1+1
         DEX
         BNE   :FULL      ; LOOP UNTIL PAGES DONE
*
** NOW DO REMAINING BYTES
*
:PART
         LDX   :PROD
         BEQ   :MFEXIT
         LDY   #0
:PARTLP
         STA   (ADDR1),Y
         INY
         DEX
         BNE   :PARTLP    ; LOOP UNTIL DONE
:MFEXIT
*
** NOW SET SIZES
*
         LDY   #0
         LDA   :AXBAK
         STA   (ADDR1),Y
         INY
         LDA   :AYBAK
         STA   (ADDR1),Y
         INY
         LDA   :MCAND
         STA   (ADDR1),Y
*
** RESTORE RETURN ADDRESS
*
         LDA   RETADR+1
         PHA
         LDA   RETADR
         PHA
*
** RETURN POINTER TO STARTING ADDRESS OF ARRAY
*
         LDY   ADDR1
         LDX   ADDR1+1
*
         RTS
*
** DATA
*
:PROD    DS    4
:AXSIZE  DS    1
:AYSIZE  DS    1
:AXBAK   DS    1
:AYBAK   DS    1
:MLIER   DS    2
:MCAND   DS    2
*
*``````````````````````````````*
* AGET82 :: INIT 2D ARRAY      *
*-                            -*
* THIS GETS THE ADDRESS OF AN  *
* ELEMENT AT THE INDEX X,Y IN  *
* THE SPECIFIED ARRAY.         *
*-                            -*
* CLOBBERS:                    *
*                              *
* FLAGS:  ????----  REG: AXYM  *
*-                            -*
* CYCLES: ???                  *
* SIZE:                        *
*-                            -*
* USAGE:                       *
*                              *
*   LDA #>$300 ; ARRAY ADDR    *
*   PHA                        *
*   LDA #<$300                 *
*   PHA                        *
*   LDA #2 ; X INDEX           *
*   PHA                        *
*   LDA #3 ; Y INDEX           *
*   PHA                        *
*   JSR AGET82                 *
*-                            -*
* ENTRY                        *
*                              *
* TOP OF STACK                 *
*                              *
* LOW BYTE OF RETURN ADDRESS   *
* HI BYTE OF RETURN ADDRESS    *
* Y INDEX OF ELEMENT           *
* X INDEX OF ELEMENT           *
* LOW BYTE OF ARRAY ADDRESS    *
* HIGH BYTE OF ARRAY ADDRESS   *
*-                            -*
* EXIT                         *
*                              *
* TOP OF STACK                 *
*                              *
* LOW BYTE OF RETURN ADDRESS   *
* HI BYTE OF RETURN ADDRESS    *
*                              *
*   Y = LO BYTE OF ELEM ADDR   *
*   X = HI BYTE OF ELEM ADDR   *
*   A = CLOBBERED; TRASH       *
*,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,*
*
AGET82
*
** SAVE RETURN ADDRESS
*
         PLA
         STA   RETADR
         PLA
         STA   RETADR+1
*
** GET PARAMETERS
*
         PLA
         STA   :YIDX
         PLA
         STA   :XIDX
         PLA
         STA   ADDR1
         PLA
         STA   ADDR1+1
*
         LDY   #2
         LDA   (ADDR1),Y  ; ELEMENT LENGTH
         STA   :MCAND     ; ELEMENT LENGTH
*
** MULTIPLY X AND Y
*
         LDA   #0
         TAY
         STY   SCRATCH
         BEQ   :ENTLP
*
:DOADD
         CLC
         ADC   :XIDX
         TAX
*
         TYA
         ADC   SCRATCH
         TAY
         TXA
*
:LP
         ASL   :XIDX
         ROL   SCRATCH
:ENTLP
         LSR   :YIDX
         BCS   :DOADD
         BNE   :LP
*
         STX   :MLIER
         STY   :MLIER+1
*
** NOW MULTIPLY BY LENGTH OF ELEMENTS
*
         LDA   #0
         STA   :PROD+2
         STA   :PROD+3
         LDX   #$10
:SHIFTR  LSR   :MLIER+1
         ROR   :MLIER
         BCC   :ROTR
         LDA   :PROD+2
         CLC
         ADC   :MCAND
         STA   :PROD+2
         LDA   :PROD+3
         ADC   :MCAND+1
:ROTR
         ROR
         STA   :PROD+3
         ROR   :PROD+2
         ROR   :PROD+1
         ROR   :PROD
         DEX
         BNE   :SHIFTR
*
         INC   :PROD      ; INCREASE BY 3
         INC   :PROD
         INC   :PROD
*
** NOW ADD BASE ADDRESS OF ARRAY TO GET
** THE ADDRESS OF THE INDEX VALUE
*
         CLC
         LDA   :PROD
         ADC   ADDR1
         STA   :PROD
         LDA   :PROD+1
         ADC   ADDR1+1
         STA   :PROD+1
*
** RETURN ADDRESS IN Y(LOW) AND X(HIGH)
*
         LDY   :PROD
         LDX   :PROD+1
*
** RESTORE RETURN ADDRESS
*
         LDA   RETADR+1
         PHA
         LDA   RETADR
         PHA
*
         RTS
*
** DATA
*
:XIDX    DS    2
:YIDX    DS    2
:PROD    DS    4
:MLIER   DS    2
:MCAND   DS    2
*
*``````````````````````````````*
* APUT82 :: PUT DATA INTO ELEM *
*-                            -*
* THIS PUTS DATA FROM ONE ADDR *
* INTO THE ADDRESS OF AN ARRAY *
* WITH THE INDEX OF X,Y.       *
*-                            -*
* CLOBBERS:                    *
*                              *
* FLAGS:  ????----  REG: AXYM  *
*-                            -*
* CYCLES: ???                  *
* SIZE:                        *
*-                            -*
* USAGE:                       *
*                              *
*   LDA #>$300 ; SOURCE DATA   *
*   PHA                        *
*   LDA #<$300                 *
*   PHA                        *
*   LDA #>$3A0 ; DEST ARRAY    *
*   PHA                        *
*   LDA #<$3A0                 *
*   PHA                        *
*   LDA #2 ; ELEM X INDEX      *
*   PHA                        *
*   LDA #3 ; ELEM Y INDEX      *
*   PHA                        *
*   JSR APUT82                 *
*-                            -*
* ENTRY                        *
*                              *
* TOP OF STACK                 *
*                              *
* LOW BYTE OF RETURN ADDRESS   *
* HI BYTE OF RETURN ADDRESS    *
* ELEMENT Y INDEX              *
* ELEMENT X INDEX              *
* LOW BYTE OF DESTINATION ADDR *
* HI BYTE OF DESTINATION ADDR  *
* LO BYTE OF SOURCE ADDRESS    *
* HI BYTE OF SOURCE ADDRESS    *
*-                            -*
* EXIT                         *
*                              *
* TOP OF STACK                 *
*                              *
* LOW BYTE OF RETURN ADDRESS   *
* HI BYTE OF RETURN ADDRESS    *
*                              *
*   Y = LOBYTE ELEMENT ADDRESS *
*   X = HIBYTE ELEMENT ADDRESS *
*   A = ELEMENT BYTE LENGTH    *
*,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,*
*
APUT82
*
** SAVE RETURN ADDRESS
*
         PLA
         STA   :RETADR    ; LOCAL BECAUSE OF
         PLA              ; CALLING AGET82
         STA   :RETADR+1
*
** GET PARAMETERS
*
         PLA
         STA   :YIDX      ; Y INDEX
         PLA
         STA   :XIDX      ; X INDEX
         PLA
         STA   ADDR4      ; ADDRESS OF ARRAY
         PLA
         STA   ADDR4+1
         PLA
         STA   ADDR3      ; ADDRESS OF DATA
         PLA              ; TO BE COPIED
         STA   ADDR3+1
*
** NOW RUN AGET82 TO GET PROPER ADDRESS
*
         LDA   ADDR4+1    ; ARRAY ADDRESS
         PHA
         LDA   ADDR4
         PHA
         LDA   :XIDX      ; X INDEX
         PHA
         LDA   :YIDX      ; Y INDEX
         PHA
         JSR   AGET82
         STY   ADDR2      ; STORE ADDRESS OF INDEX
         STX   ADDR2+1    ; IN ZERO PAGE
*
** GET ARRAY ELEMENT SIZE
*
         LDY   #2
         LDA   (ADDR4),Y
         STA   :ESIZE
         LDY   #0
*
** COPY FROM SRC ADDR TO DEST ADDR
*
:CLP
         LDA   (ADDR3),Y
         STA   (ADDR2),Y
         INY
         CPY   :ESIZE
         BNE   :CLP
*
** RESTORE RETURN ADDRESS
*
         LDA   :RETADR+1
         PHA
         LDA   :RETADR
         PHA
*
** RETURN ELEMENT ADDRESS AND SIZE
*
         LDX   ADDR2+1
         LDY   ADDR2
         LDA   :ESIZE
*
         RTS
*
** DATA
*
:RETADR  DS    2
:ESIZE   DS    1
:XIDX    DS    1
:YIDX    DS    1
*
ARRAYS82X
*