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Mapper 351: Add CHR-RAM mode plus the ability to map CHR data into CPU address space

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This commit is contained in:
NewRisingSun
2022-03-21 15:53:24 +01:00
parent c01250c28d
commit dc1d14f3cd
1 changed files with 45 additions and 16 deletions
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61
src/boards/351.c
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@@ -31,6 +31,8 @@ static uint8 VRCIRQ_latch;
static uint8 VRCIRQ_mode;
static uint8 VRCIRQ_count;
static signed short int VRCIRQ_cycles;
static uint8 *CHRRAM =NULL;
static uint8 *PRGCHR =NULL;
static SFORMAT stateRegs[] = {
{ reg, 4, "REGS" },
@@ -63,34 +65,36 @@ static void sync () {
int chrOR;
int prgAND =reg[2] &0x04? 0x0F: 0x1F;
int prgOR =reg[1] >>1;
if (reg[2] &0x80) { /* NROM mode */
int chip =reg[2] &0x01 && CHRRAM? 0x10: 0x00;
if (reg[2] &0x10) { /* NROM mode */
if (reg[2] &0x04) { /* NROM-128 */
setprg16(0x8000, prgOR >>1);
setprg16(0xC000, prgOR >>1);
setprg16r(chip, 0x8000, prgOR >>1);
setprg16r(chip, 0xC000, prgOR >>1);
} else /* NROM-256 */
setprg32(0x8000, prgOR >>2);
setprg32r(chip, 0x8000, prgOR >>2);
} else
if (~reg[0] &0x02) { /* MMC3 mode */
setprg8(0x8000 ^(MMC3_index <<8 &0x4000), MMC3_reg[6] &prgAND | prgOR &~prgAND);
setprg8(0xA000, MMC3_reg[7] &prgAND | prgOR &~prgAND);
setprg8(0xC000 ^(MMC3_index <<8 &0x4000), 0xFE &prgAND | prgOR &~prgAND);
setprg8(0xE000, 0xFF &prgAND | prgOR &~prgAND);
setprg8r(chip, 0x8000 ^(MMC3_index <<8 &0x4000), MMC3_reg[6] &prgAND | prgOR &~prgAND);
setprg8r(chip, 0xA000, MMC3_reg[7] &prgAND | prgOR &~prgAND);
setprg8r(chip, 0xC000 ^(MMC3_index <<8 &0x4000), 0xFE &prgAND | prgOR &~prgAND);
setprg8r(chip, 0xE000, 0xFF &prgAND | prgOR &~prgAND);
} else
if (reg[0] &0x01) { /* VRC4 mode */
setprg8(0x8000 ^(VRC4_misc <<13 &0x4000), VRC4_prg[0] &prgAND | prgOR &~prgAND);
setprg8(0xA000, VRC4_prg[1] &prgAND | prgOR &~prgAND);
setprg8(0xC000 ^(VRC4_misc <<13 &0x4000), 0xFE &prgAND | prgOR &~prgAND);
setprg8(0xE000, 0xFF &prgAND | prgOR &~prgAND);
setprg8r(chip, 0x8000 ^(VRC4_misc <<13 &0x4000), VRC4_prg[0] &prgAND | prgOR &~prgAND);
setprg8r(chip, 0xA000, VRC4_prg[1] &prgAND | prgOR &~prgAND);
setprg8r(chip, 0xC000 ^(VRC4_misc <<13 &0x4000), 0xFE &prgAND | prgOR &~prgAND);
setprg8r(chip, 0xE000, 0xFF &prgAND | prgOR &~prgAND);
} else { /* MMC1 mode */
prgAND >>=1;
prgOR >>=1;
if (MMC1_reg[0] &0x8) { /* 16 KiB mode */
if (MMC1_reg[0] &0x04) { /* OR logic */
setprg16(0x8000, MMC1_reg[3] &prgAND | prgOR &~prgAND);
setprg16(0xC000, 0xFF &prgAND | prgOR &~prgAND);
setprg16r(chip, 0x8000, MMC1_reg[3] &prgAND | prgOR &~prgAND);
setprg16r(chip, 0xC000, 0xFF &prgAND | prgOR &~prgAND);
} else { /* AND logic */
setprg16(0x8000, 0x00 &prgAND | prgOR &~prgAND);
setprg16(0xC000, MMC1_reg[3] &prgAND | prgOR &~prgAND);
setprg16r(chip, 0x8000, 0x00 &prgAND | prgOR &~prgAND);
setprg16r(chip, 0xC000, MMC1_reg[3] &prgAND | prgOR &~prgAND);
}
} else
setprg32(0x8000, (MMC1_reg[3] &prgAND | prgOR &~prgAND) >>1);
@@ -98,6 +102,9 @@ static void sync () {
chrAND =reg[2] &0x10? 0x1F: reg[2] &0x20? 0x7F: 0xFF;
chrOR =reg[0] <<1;
if (reg[2] &0x01) /* CHR RAM mode */
setchr8r(0x10, 0);
else
if (reg[2] &0x40) /* CNROM mode */
setchr8(chrOR >>3);
else
@@ -286,12 +293,34 @@ static void Mapper351_reset (void) {
sync();
}
static void Mapper351_close(void) {
if (CHRRAM) FCEU_gfree(CHRRAM);
if (PRGCHR) FCEU_gfree(PRGCHR);
CHRRAM =NULL;
PRGCHR =NULL;
}
void Mapper351_Init (CartInfo *info) {
int CHRRAMSIZE =info->CHRRamSize + info->CHRRamSaveSize;
info->Reset = Mapper351_reset;
info->Power = Mapper351_power;
info->Close = Mapper351_close;
MapIRQHook = cpuCycle;
GameHBIRQHook = horizontalBlanking;
GameStateRestore = Mapper351_restore;
AddExState(stateRegs, ~0, 0, 0);
if (CHRRAMSIZE) {
CHRRAM =(uint8 *)FCEU_gmalloc(CHRRAMSIZE);
SetupCartCHRMapping(0x10, CHRRAM, CHRRAMSIZE, 1);
AddExState(CHRRAM, CHRRAMSIZE, 0, "CRAM");
/* This crazy thing can map CHR-ROM into CPU address space. Allocate a combined PRG+CHR address space and treat it a second "chip". */
PRGCHR =(uint8 *)FCEU_gmalloc(PRGsize[0] +CHRsize[0]);
memcpy(PRGCHR, PRGptr[0], PRGsize[0]);
memcpy(PRGCHR +PRGsize[0], CHRptr[0], CHRsize[0]);
SetupCartPRGMapping(0x10, PRGCHR, PRGsize[0] +CHRsize[0], 0);
}
}