fonts + right sdl dimensions

2 files changed, 6 insertions, 2 deletions

diff --git a/chip8.c b/chip8.c
index 6b7040d..a911656 100644
--- a/chip8.c
+++ b/chip8.c
@@ -39,6 +39,10 @@ static u8 font[] = {
 
 void init_vm() {
   vm.PC = 0x200; // start of chip8 programs
+
+  for (int i = 0; i < sizeof(font); i++) {
+    vm.rom[0x100 + i] = font[i];
+  }
 }
 
 void load_rom(char *file_path) {
@@ -242,7 +246,7 @@ void vm_step() {
           vm.I += vm.Vx[in>>8&0xF];
           break;
         case 0x29: // LD F, Vx
-          // characters
+          vm.I = 0x100 + (vm.Vx[in>>8&0xF] * 5);
           break;
         case 0x33: // LD B, Vx
           vm.rom[vm.I] = (vm.Vx[in>>8&0xF] / 100);
diff --git a/ui_sdl.c b/ui_sdl.c
index ccadcbf..2295a74 100644
--- a/ui_sdl.c
+++ b/ui_sdl.c
@@ -28,7 +28,7 @@ void draw() {
   SDL_RenderClear(r);
   SDL_SetRenderDrawColor(r, 160, 200, 255, 255);
   //SDL_RenderFillRect(r, &box);
-  for (int x = 0; x < 0x3F; x++) {
+  for (int x = 0; x <= 0x3F; x++) {
     for (int y = 0; y <= 0x1F; y++) {
       int byte = y * 64 + x;
       int bit = byte & 0x07;