some colorization fixes

nes/nescoundrel.c

@@ -30,6 +30,14 @@
 #define GAME_YELLOW 2
 #define GAME_GREEN 3
 
+void ppu_off() {
+  PPU.mask &= 0xE7;
+}
+
+void ppu_on() {
+  PPU.mask |= 0x1A;
+}
+
 int joy_input_wait() {
   unsigned char last_joy = 0, joy, pressed;
   /* wait until the previous key is released */
@@ -88,6 +96,7 @@ void game_startup() {
   textcolor(0);
   init_palette();
   clrscr();
+  ppu_off();
   for(j=0;j<24;j+=4)
     for(i=3;i<32;i+=4)
       colorxy(i, j, 1 + ((++entropy) % 3));
@@ -120,6 +129,7 @@ void game_startup() {
   cputsxy(1, SCREEN_HEIGHT - 2, "Luxferre");
   cputsxy(SCREEN_WIDTH-5, SCREEN_HEIGHT - 2, "2026");
   joy_install(joy_static_stddrv);
+  ppu_on();
   while(1) {
     ++entropy;
     joy = joy_read(JOY_1);
@@ -134,6 +144,7 @@ void game_startup() {
 void win_screen(int score) {
   unsigned char i, j;
   clrscr();
+  ppu_off();
   for(j=0;j<12;j+=4)
     for(i=3;i<32;i+=4)
       colorxy(i, j, 1 + (rand() % 3));
@@ -153,6 +164,7 @@ void win_screen(int score) {
   cputs("\r\nOriginal concept by Zach Gage\r\nand Kurt Bieg, 2011");
   chlinexy(0, 23, SCREEN_WIDTH);
   cputsxy(10, 25, "Press Start");
+  ppu_on();
   while(joy_input_wait() != KEY_ST);
 }
 
@@ -273,6 +285,7 @@ void render_main_scene() {
   for(i=0;i<sizeof(deck);i++)
     if(deck[i]) deck_count++;
   clrscr();
+  ppu_off();
   /* render the frames */
   chlinexy(0,SCREEN_HEIGHT-1,SCREEN_WIDTH);
   chlinexy(0,SCREEN_HEIGHT-3,SCREEN_WIDTH);
@@ -299,6 +312,8 @@ void render_main_scene() {
   /* render status message */
   gotoxy(1, SCREEN_HEIGHT-2);
   cprintf("%s", status_msg);
+  ppu_on();
+  waitvsync();
 }
 
 /* Confirmation method */