162 lines
5.0 KiB
NASM
162 lines
5.0 KiB
NASM
;--------------------------------------------------------------------------------
|
|
WriteSaveChecksum:
|
|
LDX.w #$0000 : TXA : - ; Checksum first $04FE bytes
|
|
CLC : ADC.l SaveDataWRAM, X
|
|
INX #2
|
|
CPX #$04FE : BNE -
|
|
LDX.w #$0000 : - ; Checksum extended save data
|
|
CLC : ADC.l ExtendedFileNameWRAM, X
|
|
INX #2
|
|
CPX #$0FFE : BNE -
|
|
STA.b $00
|
|
LDA.w #$5A5A
|
|
SEC : SBC.b $00
|
|
STA.l $7004FE
|
|
RTL
|
|
;--------------------------------------------------------------------------------
|
|
ValidateSRAM:
|
|
REP #$30
|
|
LDX.w #$0000 : TXA : - ; Checksum first $04FE bytes
|
|
CLC : ADC.l CartridgeSRAM,X
|
|
INX #2
|
|
CPX.w #$04FE : BNE -
|
|
LDX.w #$0000 : - ; Checksum extended save data
|
|
CLC : ADC.l ExtendedFileNameSRAM, X
|
|
INX #2
|
|
CPX #$0FFE : BNE -
|
|
STA.b $00
|
|
LDA.w #$5A5A
|
|
SEC : SBC.b $00
|
|
CMP.l InverseChecksumSRAM : BEQ +
|
|
TDC : STA.l FileValiditySRAM : + ; Delete save by way of zeroing validity marker
|
|
LDX.w #$00FE : - ; includes prize pack reset after save and quit
|
|
STZ $0D00, X
|
|
STZ $0E00, X
|
|
STZ $0F00, X
|
|
DEX #2
|
|
BPL -
|
|
SEP #$30
|
|
RTL
|
|
;--------------------------------------------------------------------------------
|
|
ClearExtendedSaveFile:
|
|
STA $700400, X ; what we wrote over
|
|
STA $700500, X
|
|
STA $700600, X
|
|
STA $700700, X
|
|
STA $700800, X
|
|
STA $700900, X
|
|
STA $700A00, X
|
|
STA $700B00, X
|
|
STA $700C00, X
|
|
STA $700D00, X
|
|
STA $700E00, X
|
|
STA $700F00, X
|
|
STA $701000, X
|
|
STA $701100, X
|
|
STA $701200, X
|
|
STA $701300, X
|
|
STA $701400, X
|
|
RTL
|
|
;--------------------------------------------------------------------------------
|
|
ClearExtendedWRAMSaveFile:
|
|
STA $7EF400, X ; what we wrote over
|
|
STA $7F6000, X
|
|
STA $7F6100, X
|
|
STA $7F6200, X
|
|
STA $7F6300, X
|
|
STA $7F6400, X
|
|
STA $7F6500, X
|
|
STA $7F6600, X
|
|
STA $7F6700, X
|
|
STA $7F6800, X
|
|
STA $7F6900, X
|
|
STA $7F6A00, X
|
|
STA $7F6B00, X
|
|
STA $7F6C00, X
|
|
STA $7F6D00, X
|
|
STA $7F6E00, X
|
|
STA $7F6F00, X
|
|
RTL
|
|
;--------------------------------------------------------------------------------
|
|
CopyExtendedSaveFileToWRAM:
|
|
PHA
|
|
SEP #$30
|
|
LDA $4300 : PHA ; preserve DMA parameters
|
|
LDA $4301 : PHA ; preserve DMA parameters
|
|
LDA $4302 : PHA ; preserve DMA parameters
|
|
LDA $4303 : PHA ; preserve DMA parameters
|
|
LDA $4304 : PHA ; preserve DMA parameters
|
|
LDA $4305 : PHA ; preserve DMA parameters
|
|
LDA $4306 : PHA ; preserve DMA parameters
|
|
;--------------------------------------------------------------------------------
|
|
LDA #$00 : STA $4300 ; set DMA transfer direction A -> B, bus A auto increment, single-byte mode
|
|
|
|
LDA #$80 : STA $4301 ; set bus B source to WRAM register
|
|
|
|
LDA #$00 : STA $2181 ; set WRAM register source address
|
|
LDA #$60 : STA $2182
|
|
LDA #$7F : STA $2183
|
|
|
|
STZ $4302 ; set bus A destination address to SRAM
|
|
LDA #$05 : STA $4303
|
|
LDA #$70 : STA $4304
|
|
|
|
LDA #$00 : STA $4305 ; set transfer size to 0x1000
|
|
LDA #$10 : STA $4306 ; STZ $4307
|
|
|
|
LDA #$01 : STA $420B ; begin DMA transfer
|
|
;--------------------------------------------------------------------------------
|
|
PLA : STA $4306 ; restore DMA parameters
|
|
PLA : STA $4305 ; restore DMA parameters
|
|
PLA : STA $4304 ; restore DMA parameters
|
|
PLA : STA $4303 ; restore DMA parameters
|
|
PLA : STA $4302 ; restore DMA parameters
|
|
PLA : STA $4301 ; restore DMA parameters
|
|
PLA : STA $4300 ; restore DMA parameters
|
|
REP #$30
|
|
PLA
|
|
STA $7EC00D ; what we wrote over
|
|
RTL
|
|
;--------------------------------------------------------------------------------
|
|
CopyExtendedWRAMSaveFileToSRAM:
|
|
PHA
|
|
PHB
|
|
SEP #$30
|
|
LDA #$00 : PHA : PLB
|
|
LDA $4300 : PHA ; preserve DMA parameters
|
|
LDA $4301 : PHA ; preserve DMA parameters
|
|
LDA $4302 : PHA ; preserve DMA parameters
|
|
LDA $4303 : PHA ; preserve DMA parameters
|
|
LDA $4304 : PHA ; preserve DMA parameters
|
|
LDA $4305 : PHA ; preserve DMA parameters
|
|
LDA $4306 : PHA ; preserve DMA parameters
|
|
;--------------------------------------------------------------------------------
|
|
LDA #$80 : STA $4300 ; set DMA transfer direction B -> A, bus A auto increment, single-byte mode
|
|
|
|
STA $4301 ; set bus B source to WRAM register
|
|
|
|
LDA #$00 : STA $2181 ; set WRAM register source address
|
|
LDA #$60 : STA $2182
|
|
LDA #$7F : STA $2183
|
|
|
|
STZ $4302 ; set bus A destination address to SRAM
|
|
LDA #$05 : STA $4303
|
|
LDA #$70 : STA $4304
|
|
|
|
LDA #$10 : STA $4305 ; set transfer size to 0xB00
|
|
LDA #$0B : STA $4306 ; STZ $4307
|
|
|
|
LDA #$01 : STA $420B ; begin DMA transfer
|
|
;--------------------------------------------------------------------------------
|
|
PLA : STA $4306 ; restore DMA parameters
|
|
PLA : STA $4305 ; restore DMA parameters
|
|
PLA : STA $4304 ; restore DMA parameters
|
|
PLA : STA $4303 ; restore DMA parameters
|
|
PLA : STA $4302 ; restore DMA parameters
|
|
PLA : STA $4301 ; restore DMA parameters
|
|
PLA : STA $4300 ; restore DMA parameters
|
|
REP #$30
|
|
PLB
|
|
PLA
|
|
RTL
|