diff --git a/src/main.c b/src/main.c
index 7d96d27..6c0c25f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -50,15 +50,11 @@ init_chip8(void)
 {
     srand(time(NULL));
 
-    for (register uint_fast8_t t = 0; t < 16; ++t) {
-        v[t] = 0;
-        stack[t] = 0;
-        key[t] = 0;
-    }
-
-    for (register uint_fast8_t x = 0; x < 64; ++x)
-        for (register uint_fast8_t y = 0; y < 32; ++y)
-            gfx[x][y] = 0;
+    memset(v, 0, 16 * sizeof(byte));
+    memset(stack, 0, 16 * sizeof(word));
+    memset(key, 0, 16 * sizeof(byte));
+    memset(gfx, 0, 32 * 64 * sizeof(byte));
+    memset(oldgfx, 0, 32 * 64 * sizeof(byte));
 
     const byte fontset[80] = {
         0xF0, 0x90, 0x90, 0x90, 0xF0, // 0
@@ -79,11 +75,8 @@ init_chip8(void)
         0xF0, 0x80, 0xF0, 0x80, 0x80  // F
     };
 
-    for (register uint_fast8_t t = 0; t < 80; ++t)
-        memory[t] = fontset[t];
-
-    for (register uint_fast16_t t = 80; t < 4096; ++t)
-        memory[t] = 0;
+    memcpy(memory, fontset, 80 * sizeof(byte));
+    memset(memory + 80, 0, 4016);
 }
 
 void
@@ -332,9 +325,7 @@ op_handler(void)
 {
     switch (op) {
         case 0x00E0:
-            for (register uint_fast8_t x = 0; x < 64; ++x)
-                for (register uint_fast8_t y = 0; y < 32; ++y)
-                    gfx[x][y] = 0;
+            memset(gfx, 0, 32 * 63 * sizeof(byte));
 
             SDL_Rect r;
             r.h = 32 * SCALE;
@@ -500,12 +491,7 @@ op_handler(void)
                                     pc += 2;
                                     return 1;
                                 case 0xD000:
-                                    for (register uint_fast8_t x = 0; x < 64;
-                                         ++x)
-                                        for (register uint_fast8_t y = 0;
-                                             y < 32;
-                                             ++y)
-                                            oldgfx[x][y] = gfx[x][y];
+                                    memcpy(oldgfx, gfx, 32 * 64 * sizeof(byte));
 
                                     v[0xF] = 0;