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Mapper 340: Add submapper 1. Add CHR-RAM write protection in NROM mode, needed for B-Wings.

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NewRisingSun
2026-02-04 16:03:00 +01:00
parent febdbaca08
commit d74d4c18b6
1 changed files with 11 additions and 3 deletions
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14
src/boards/340.c
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@@ -21,23 +21,31 @@
#include "mapinc.h"
#include "asic_latch.h"
/* Submapper 0 - K-3008, K-3032, K-3036 PCBs: H mirroring via A2 in NROM mode, and via A6 in UNROM mdoe.
Submapper 1 - K-3055 PCB: H mirroring via A2 in NROM mode, and via A3=0,A4=1 in UNROM mode (used by Thundercade).
*/
static uint8 submapper;
static void sync () {
int prg = Latch_address >>2 &0x20 | Latch_address &0x1F;
if (Latch_address &0x20) {
if (Latch_address &0x20) { /* NROM mode */
if (Latch_address &0x01) {
setprg16(0x8000, prg);
setprg16(0xC000, prg);
} else
setprg32(0x8000, prg >>1);
} else {
setmirror(Latch_address &0x04? MI_H: MI_V);
} else { /* UNROM mode */
setprg16(0x8000, prg);
setprg16(0xC000, prg | 7);
setmirror(Latch_address &0x40 && submapper != 1 || ~Latch_address &0x08 && Latch_address &0x10 && submapper == 1? MI_H: MI_V);
}
SetupCartCHRMapping(0, CHRptr[0], 0x2000, Latch_address &0x20? 0: 1);
setchr8(0);
setmirror(Latch_address &0x040 || (Latch_address &0x025) == 0x025 || (Latch_address &0x118) == 0x010? MI_H: MI_V);
}
void Mapper340_Init (CartInfo *info) {
submapper = info->submapper;
Latch_init(info, sync, 0x8000, 0xFFFF, NULL);
info->Reset = Latch_clear;
}