A .gitignore

@@ -0,0 +1,2 @@ 
+xyw.exe
+*.o

A Makefile

@@ -0,0 +1,14 @@ 
+CC = gcc
+CFLAGS = -Wall -Wextra -g
+LDFLAGS =
+
+.PHONY: clean
+
+xyw: xyw.o
+	$(CC) $(CFLAGS) $(LDFLAGS) xyw.o -o xyw 
+
+xyw.o: xyw.c xyw.h
+	$(CC) $(CFLAGS) -c xyw.c -o xyw.o
+
+clean:
+	rm -f xyw xyw.exe xyw.o

M xyw.c → xyw.c

@@ -1,7 +1,5 @@ 
 #include <stdio.h>
-
-typedef unsigned char xyw_byte;
-typedef unsigned short xyw_short;
+#include "xyw.h"
 
 #define MEMORY_SIZE 0xffff
 #define STACK_SIZE 0xff
@@ -20,7 +18,8 @@ #define SYSTEM_Y 0x05
 #define SYSTEM_XW 0x06
 #define SYSTEM_YW 0x08
 #define SYSTEM_PC 0x0A
-#define SYSTEM_ON_ERROR 0x0C
+#define SYSTEM_PAGE 0x0C
+#define SYSTEM_ON_ERROR 0x0D
 
 /* console device */
 #define CONSOLE_BASE 0x10
@@ -50,25 +49,27 @@ #define FILE_READ 0x35
 #define FILE_WRITE 0x36
 #define FILE_APPEND 0x37
 
-/* video device */
-#define VIDEO_WIDTH 0x40
-#define VIDEO_HEIGHT 0x41
-#define VIDEO_FILL 0x42
-#define VIDEO_X 0x43
-#define VIDEO_Y 0x44
-#define VIDEO_ON_RENDER 0x45
+/* display device */
+#define DISPLAY_WIDTH 0x40
+#define DISPLAY_HEIGHT 0x41
+#define DISPLAY_FILL 0x42
+#define DISPLAY_X 0x43
+#define DISPLAY_Y 0x44
+#define DISPLAY_ON_RENDER 0x45
 
-/* audio device */
-#define AUDIO_STATE 0x50
-#define AUDIO_SAMPLES 0x51
-#define AUDIO_N_SAMPLES 0x53
-#define AUDIO_ON_STOP 0x55
+/* display device */
+#define BUZZER_STATE 0x50
+#define BUZZER_SAMPLES 0x51
+#define BUZZER_N_SAMPLES 0x53
+#define BUZZER_ON_STOP 0x55
 
 xyw_byte xyw_memory[MEMORY_SIZE];
+xyw_byte system_stack[STACK_SIZE];
+xyw_byte user_stack[STACK_SIZE];
 
 //// 1-byte pointers
-xyw_byte *ssp = &xyw_memory[SYSTEM_STACK_START];
-xyw_byte *usp = &xyw_memory[USER_STACK_START];
+xyw_byte *ssp = &xyw_memory[SYSTEM_SSP];
+xyw_byte *usp = &xyw_memory[SYSTEM_USP];
 xyw_byte *x = &xyw_memory[SYSTEM_X];
 xyw_byte *y = &xyw_memory[SYSTEM_Y];
 
@@ -102,3 +103,10 @@ static inline void xw_add(int delta) { madd(SYSTEM_XW, delta); }
 static inline xyw_short yw(void) { return mget(SYSTEM_YW); }
 static inline void yw_set(xyw_short val) { mset(SYSTEM_YW, val); }
 static inline void yw_add(int delta) { madd(SYSTEM_YW, delta); }
+
+//// Main Function
+int main(int argc, char *argv[])
+{
+    (void)argc;
+    (void)argv;
+}

A xyw.h

@@ -0,0 +1,7 @@ 
+#ifndef XYW_H
+#define XYW_H
+
+typedef unsigned char xyw_byte;
+typedef unsigned short xyw_short;
+
+#endif // XYW_H