diff --git a/src/f6502.c b/src/f6502.c
index 8a664b7..2a23007 100644
--- a/src/f6502.c
+++ b/src/f6502.c
@@ -39,7 +39,7 @@ static inline uint8_t f6502_read(nes_Memory* mem,
     return mem->ram[addr];
 #else
     if (addr >= 0x8000U) {
-        return mem->rom_bank[(addr - 0x8000U) >> 13][addr & 0x1FFFFU];
+        return mem->rom_bank[(addr - 0x8000U) >> 13][addr & 0x1FFFU];
     }
 
     switch (addr & 0x6000U) {
@@ -1548,5 +1548,6 @@ int f6502_step(f6502_Core* core, int clocks) {
     }
 */
     clocks_elapsed += f6502_check_interrupts(core);
-    return (clocks_elapsed + f6502_do_step(core, clocks));
+    return (    f6502_do_step(core, clocks - clocks_elapsed) +
+                clocks_elapsed);
 }
diff --git a/src/nes.c b/src/nes.c
index c511048..801c6e0 100644
--- a/src/nes.c
+++ b/src/nes.c
@@ -6,6 +6,14 @@
 
 void nes_init(nes* sys) {
     f6502_init(&sys->core);
+    // TODO: Init PPU
+    // TODO: Init APU
+}
+
+void nes_reset(nes* sys) {
+    f6502_reset(&sys->core);
+    // TODO: Reset PPU
+    // TODO: Reset APU
 }
 
 void nes_done(nes* sys) {
@@ -15,7 +23,11 @@ void nes_done(nes* sys) {
 static int nes_vsync(nes* sys) {
     int status = 0;
 
-    // TODO: PPU Set VBlank flag
+    sys->core.memory.ppu.status |= ppu_Status_VBlank;
+    if (sys->core.memory.ppu.ctrl & ppu_Control_VBlank) {
+        f6502_set_NMI(&sys->core, 1);
+    }
+
     // TODO: APU Sync
     // TODO: APU Frame IRQ
 
@@ -25,8 +37,6 @@ static int nes_vsync(nes* sys) {
         status = nese_update_input(&sys->input);
     }
 
-    // TODO: NMI
-
     return status;
 }
 
@@ -56,6 +66,7 @@ static int nes_hsync(nes* sys) {
 
     switch (sys->ppu.scanline) {
     case nes_ppu_prerender_line:
+        f6502_set_NMI(&sys->core, 0);
         sys->core.memory.ppu.status &= ~(   ppu_Status_VBlank |
                                             ppu_Status_Hit);
         nes_ppu_find_hit_line(&sys->ppu, &sys->core.memory.ppu);
diff --git a/src/nes.h b/src/nes.h
index 2c3b333..6887c7d 100644
--- a/src/nes.h
+++ b/src/nes.h
@@ -17,6 +17,7 @@ typedef struct {
 } nes;
 
 void nes_init(nes*);
+void nes_reset(nes*);
 void nes_done(nes*);
 int nes_loop(nes*);
 
diff --git a/src/nese.c b/src/nese.c
index 057e6c7..d1a8a2a 100644
--- a/src/nese.c
+++ b/src/nese.c
@@ -39,6 +39,8 @@ int nese_start(nes* sys, const char* filename) {
 
     nes_init(sys);
 
+    nes_reset(sys);
+
     nes_loop(sys);
 
     if (cart_data) nese_unmap_file(cart_data, filesize);