various changes?

1 files changed, 16 insertions, 9 deletions

diff --git a/src/apple.c b/src/apple.c
index ec7769a..52ef358 100644
--- a/src/apple.c
+++ b/src/apple.c
@@ -1,17 +1,21 @@
 #include"apple.h"
 
-void AppleOn(){
+byte* ROM;
+
+void AppleOn() {
 	Memory = calloc(MEMORY_SIZE, sizeof(byte));
+	ROM = calloc(256, sizeof(byte));
 	InitInstructionTable();
 
 	// Load ROM.
-	FILE *ROM = fopen ("rom.bin", "rb");
-	if (ROM == NULL) {
+	FILE *ROM_File = fopen ("rom.bin", "rb");
+	if (ROM_File == NULL) {
 		printf("\n\rROM does not exist.\n");
 		abort();
 	}
 	for (int i = 0; i < 256; i++) {
-		Memory[0xFF00+i] = fgetc(ROM);
+		ROM[i] = fgetc(ROM_File);
+		printf("%x", ROM[i]);
 	}
 }
 
@@ -43,18 +47,21 @@ byte ToAscii(char x)
 byte GetMemory(address x){
 	switch(x)
 	{
-		// I opted to make the kbd return successfully at all times for the sake of simplicity.
-		// This is not technically "accurate" behavior however.
+		// The keyboard does not act precisely as the real hardware, because there is no need to wait for the keyboard.
+		// So KBD_CR and DSP always return a high high-order bit, and when the keyboard data is requested it will wait for UserInput() to finish.
 	case KBD:
 		return 0b10000000 | UserInput();
 	case KBD_CR: case DSP:
 		return 0b10000000;
-	default:
-		return Memory[x];
 	}
 
+	if (x >= 0xFF00 && x <= 0xFFFF) {
+		return ROM[0x00FF & x];
+	}
 }
 
 void SetMemory(address x, byte y){
-	Memory[x] = y;
+	if (x < MEMORY_SIZE) {
+		Memory[x] = y;
+	}
 }