mirror of
https://github.com/nathanriggs/AppleIIAsm-Collection.git
synced 2024-11-30 15:49:55 +00:00
87 lines
1.9 KiB
Plaintext
87 lines
1.9 KiB
Plaintext
MEMSWAP
|
|
PLA
|
|
STA RETADR
|
|
PLA
|
|
STA RETADR+1
|
|
PLA
|
|
STA :LENGTH
|
|
PLA
|
|
STA ADDR1
|
|
STA :A1
|
|
PLA
|
|
STA ADDR1+1
|
|
STA :A1+1
|
|
PLA
|
|
STA ADDR2
|
|
STA :A2
|
|
PLA
|
|
STA ADDR2+1
|
|
STA :A2+1
|
|
LDA ERRCTRL
|
|
CMP #1
|
|
BEQ :CHKERR
|
|
JMP :ERREND
|
|
:CHKERR
|
|
LDA ADDR2+1 ; IF #>A2 => #>A1
|
|
CMP ADDR1+1
|
|
BCS :CHKLO ; CHECK LOW BYTES
|
|
JMP :A1GTA2 ; ELSE, A1 > A2
|
|
:CHKLO
|
|
LDA ADDR2
|
|
CMP ADDR1
|
|
BCS :A2GTA1
|
|
JMP :A1GTA2
|
|
:A2GTA1
|
|
LDA ADDR2 ;CALC DEST-SRC
|
|
SEC
|
|
SBC ADDR1
|
|
TAX
|
|
LDA ADDR2+1
|
|
SBC ADDR1+1 ; MOD 64K AUTOMATIC
|
|
; -- DISCARD CARRY
|
|
TAY
|
|
TXA ; CMP WITH # OF BYTES TO MOVE
|
|
CMP :LENGTH
|
|
TYA
|
|
SBC :LENGTH+1
|
|
BCS :ERREND ; BRANCH IF NO OVERLAP
|
|
JMP :OVF
|
|
:A1GTA2
|
|
LDA ADDR1
|
|
SEC
|
|
SBC ADDR2
|
|
TAX
|
|
LDA ADDR1+1
|
|
SBC ADDR2+1
|
|
TAY
|
|
TXA
|
|
CMP :LENGTH
|
|
TYA
|
|
SBC :LENGTH+1
|
|
BCS :ERREND
|
|
:OVF
|
|
_ERR :E_SID;:E_OVF;:E_DUMP;:LENGTH;#6
|
|
:ERREND
|
|
LDY #255 ; COUNTER
|
|
:LP
|
|
INY
|
|
LDA (ADDR1),Y
|
|
TAX ; X CONTAINS ADDR1 VAL
|
|
LDA (ADDR2),Y ; A CONTAINS ADDR2 VAL
|
|
STA (ADDR1),Y
|
|
TXA
|
|
STA (ADDR2),Y
|
|
CPY :LENGTH
|
|
BNE :LP
|
|
LDA RETADR+1
|
|
PHA
|
|
LDA RETADR
|
|
PHA
|
|
RTS
|
|
:LENGTH DS 2
|
|
:A1 DS 2
|
|
:A2 DS 2
|
|
:E_SID ASC "MEMSWAP (MSWAP MACRO)",00
|
|
:E_DUMP ASC "DUMPING LENGTH (2) A1(2) A2(2)",00
|
|
:E_OVF ASC "OVERFLOW! ADDRESSES OVERLAP.",00
|