Fix ROM/RAM Banking for MBC1, Pass mooneye ram_64kb.gb

sdslabs · Jan 8, 2024 · 15af8c4 · 15af8c4
1 parent 685e929
commit 15af8c4
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Showing 2 changed files with 5 additions and 3 deletions.
diff --git a/src/gameBoy.cpp b/src/gameBoy.cpp
@@ -31,7 +31,7 @@ GBE::GBE()
 		printf("boot rom file not opened");
 
 	// Open the Game ROM
-	if ((gameROM = fopen("../tests/mbc1/bits_ramg.gb", "rb")) == NULL)
+	if ((gameROM = fopen("../tests/mbc1/ram_64kb.gb", "rb")) == NULL)
 		printf("game rom file not opened");
 
 	// Set the Boot ROM

diff --git a/src/mmap.cpp b/src/mmap.cpp
@@ -185,8 +185,10 @@ bool MemoryMap::writeMemory(Word address, Byte value)
 			externalRam[address - 0xA000] = value;
 			break;
 		case MBC1:
-			if (enableRAM)
+			if (enableRAM && ((ramBankNumber * 0x2000) < ramSize))
 				externalRam[address - 0xA000 + (ramBankNumber * 0x2000)] = value;
+			else if (enableRAM)
+				externalRam[address - 0xA000] = value;
 			break;
 		default:
 			externalRam[address - 0xA000] = value;
@@ -318,7 +320,7 @@ Byte MemoryMap::readMemory(Word address)
 			return externalRam[address - 0xA000];
 		case MBC1:
 			if (enableRAM) {
-				if (ramBankNumber * 0x2000 < ramSize)
+				if ((ramBankNumber * 0x2000) < ramSize)
 					return externalRam[address - 0xA000 + (ramBankNumber * 0x2000)];
 				else
 					return externalRam[address - 0xA000];