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Update mapper 15 based on latest notes

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- bit 7 acts as A13 only on mode 2
- prg mask now 0x3F of data latche etc.
- unrolled loops
This commit is contained in:
negativeExponent
2020-02-21 22:25:56 +08:00
parent 872acac367
commit 1b01730dda
1 changed files with 28 additions and 20 deletions
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48
src/boards/15.c
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@@ -27,34 +27,42 @@ static uint8 *WRAM = NULL;
static uint32 WRAMSIZE;
static SFORMAT StateRegs[] =
{
{ &latchea, 2, "AREG" },
{ &latchea, 2 | FCEUSTATE_RLSB, "AREG" },
{ &latched, 1, "DREG" },
{ 0 }
};
static void Sync(void) {
int i;
setmirror(((latched >> 6) & 1) ^ 1);
switch (latchea) {
case 0x8000:
for (i = 0; i < 4; i++)
setprg8(0x8000 + (i << 13), (((latched & 0x7F) << 1) + i) ^ (latched >> 7));
uint32 preg[4];
uint32 bank = (latched & 0x3F) << 1;
switch (latchea & 0x03) {
case 0:
preg[0] = bank + 0;
preg[1] = bank + 1;
preg[2] = bank + 2;
preg[3] = bank + 3;
break;
case 0x8002:
for (i = 0; i < 4; i++)
setprg8(0x8000 + (i << 13), ((latched & 0x7F) << 1) + (latched >> 7));
case 2:
bank = bank | (latched >> 7);
preg[0] = bank;
preg[1] = bank;
preg[2] = bank;
preg[3] = bank;
break;
case 0x8001:
case 0x8003:
for (i = 0; i < 4; i++) {
unsigned int b;
b = latched & 0x7F;
if (i >= 2 && !(latchea & 0x2))
b = 0x7F;
setprg8(0x8000 + (i << 13), (i & 1) + ((b << 1) ^ (latched >> 7)));
}
case 1:
case 3:
preg[0] = bank + 0;
preg[1] = bank + 1;
preg[2] = (((latchea & 0x02) == 0) ? (bank | 0xE) : bank) + 0;
preg[3] = (((latchea & 0x02) == 0) ? (bank | 0xE) : bank) + 1;
break;
}
setprg8(0x8000, preg[0]);
setprg8(0xA000, preg[1]);
setprg8(0xC000, preg[2]);
setprg8(0xE000, preg[3]);
setmirror(((latched >> 6) & 1) ^ 1);
}
static DECLFW(M15Write) {
@@ -76,7 +84,7 @@ static void M15Power(void) {
SetWriteHandler(0x6000, 0x7FFF, CartBW);
SetWriteHandler(0x8000, 0xFFFF, M15Write);
SetReadHandler(0x8000, 0xFFFF, CartBR);
FCEU_CheatAddRAM(WRAMSIZE >> 10, 0x6000, WRAM);
FCEU_CheatAddRAM(WRAMSIZE >> 10, 0x6000, WRAM);
Sync();
}