Added memory manager

src/memory.c

@@ -0,0 +1,64 @@
+#include <stdint.h>
+#include "memory.h"
+
+uint8_t read6502(uint16_t address){
+	switch (address){
+		case RAMLOC ... RAMLOC + RAMSIZE:
+			return ram[address - RAMLOC];
+			break;
+			
+		case ROMLOC ... ROMLOC + ROMSIZE:
+			return rom[address - ROMLOC];
+			break;
+			
+		case VIDADDRS ... VIDADDRS + PAGESIZE:
+			if ((address - VIDADDRS) % 4 == 3) return readVideo();
+			else return 0;
+			break;
+		
+		case 0xBD00:
+			scanKeyboard();
+			return keyboardResult;
+			break;
+			
+		default: 
+			return NOP;
+			break;
+	}
+}
+
+void write6502(uint16_t address, uint8_t value){
+	switch (address){
+		case RAMLOC ... RAMLOC + RAMSIZE:
+			ram[address - RAMLOC] = value;
+			break;
+			
+		case ROMLOC ... ROMLOC + ROMSIZE:
+			rom[address - ROMLOC] = value;
+			break;
+			
+		case VIDADDRS ... VIDADDRS + PAGESIZE:
+			switch ((address - VIDADDRS) % 4){
+				case 0:			/* Video X Register */
+					videoX = value;
+					break;
+				case 1:			/* Video Y Register */
+					videoY = value;
+					break;
+				case 2:			/* Video M Register */
+					videoMode = value;
+					break;
+				case 3:			/* Video A Register */
+					videoA = value;
+					writeVideo();
+					break;
+			}
+			break;
+				case 0xBC00:
+					systemRegister = value;
+					break;
+					
+				default: 
+					break;
+	}
+}

src/memory.h

@@ -0,0 +1,21 @@
+#include <stdint.h>
+
+#include "config.h"
+
+extern void scanKeyboard();
+extern void writeVideo();
+extern uint8_t readVideo();
+extern uint8_t videoX;
+extern uint8_t videoY;
+extern uint8_t videoMode;
+extern uint8_t videoA;
+
+static int8_t ram[RAMSIZE + 1];
+static int8_t rom[ROMSIZE + 1];
+
+static uint8_t systemRegister;
+static uint8_t keyboardResult;
+
+
+uint8_t read6502(uint16_t address);
+void write6502(uint16_t address, uint8_t value);