diff --git a/programs/chip8_picture.ch8 b/programs/chip8_picture.ch8
new file mode 100644
index 0000000..74ab4bf
Binary files /dev/null and b/programs/chip8_picture.ch8 differ
diff --git a/programs/sierpinski.ch8 b/programs/sierpinski.ch8
new file mode 100644
index 0000000..e02d458
Binary files /dev/null and b/programs/sierpinski.ch8 differ
diff --git a/source/app.d b/source/app.d
index 739576f..96ca0a0 100644
--- a/source/app.d
+++ b/source/app.d
@@ -397,7 +397,7 @@ struct Chip8Status {
 
 		import std.file : read;
 
-		auto buf = read("programs/sqrt.ch8");
+		auto buf = read("programs/chip8_picture.ch8");
 		emu_.load(0x200, buf); // do ze load yes, will copy all the data in
 
 	} // loadShortcut
@@ -523,15 +523,15 @@ struct Chip8Status {
 						case SDL_SCANCODE_G: redrawShortcut(); break;
 						case SDL_SCANCODE_T: toggleRunShortcut(); break;
 						case SDL_SCANCODE_S: stepShortcut(); break;
-						case SDL_SCANCODE_Q: quitShortcut();
+						case SDL_SCANCODE_Q: quitShortcut(); break;
 						default: break;
 					}
 				} else {
 					if (ev.key.keysym.scancode == SDL_SCANCODE_ESCAPE) {
 						quitShortcut();
-						break;
 					}
 				}
+				break;
 			default:
 				break;
 		}
@@ -625,7 +625,8 @@ struct Chip8 {
 
 		cpu = cpu.init;
 		stack = stack.init;
-		ram = ram.init;
+		ram[0x200 .. $ - 1] = 0;
+		cpu.pc = 0x200;
 		sp = sp.init;
 
 		run_flag = run_flag.init;
@@ -758,7 +759,6 @@ struct Chip8 {
 						auto vx = cpu.v[x];
 						cpu.v[0xF] = (vx & 0b10000000) >> 7;
 						cpu.v[x] >>= 1;
-						cpu.v[x] /= 2;
 						break;
 
 					case 0x0007: // 0x8XY7 Sets VX to VY minus VX. VF is set to 0 when there's a borrow, and 1 when there isn't.
@@ -777,7 +777,6 @@ struct Chip8 {
 						auto vx = cpu.v[x];
 						cpu.v[0xF] = (vx & 0b10000000) >> 7;
 						cpu.v[x] <<= 1;
-						cpu.v[x] *= 2;
 						break;
 
 					default: // unhandled for some reason
@@ -801,13 +800,13 @@ struct Chip8 {
 				break;
 
 			case 0xB000: // 0xBNNN Jumps to the address NNN plus V0.
-				pc_target = cast(ubyte)cpu.opcode.capture!(0, 12) + cpu.v[0x0];
+				pc_target = cast(ProgramCounter)(cpu.opcode.capture!(0, 12) + cpu.v[0x0]);
 				break;
 
 			case 0xC000: // 0xCXNN Sets VX to the result of a bitwise and operation on a random number and NN.
 
 				import std.random : uniform;
-				auto x = cpu.opcode.capture!(8, 12);
+				auto x = cpu.opcode.capture!(0, 8);
 				cpu.v[x] = uniform(Register.min, Register.max) & cpu.opcode.capture!(0, 8);
 				break;
 
@@ -829,12 +828,19 @@ struct Chip8 {
 					ushort pixel = ram[spr_addr + row];
 
 					foreach (int col; 0 .. 8) {
-						if ((pixel & (0x80 >> col)) != 0) {
-							if (screen_buf[(x + col + ((y + row) * 64))] == 1) {
+						if ((pixel & 0x80) > 0) {
+							auto x_off = (x + col) % 64;
+							auto y_off = (y + row) % 32;
+							auto offset = x_off + (y_off * 64);
+							if (screen_buf[offset] == 1) {
 								cpu.v[0xF] = 1;
+							} else {
+								cpu.v[0xF] = 0;
 							}
-							screen_buf[x + row + ((y + col) * 64)] ^= 1;
+							screen_buf[offset] ^= 1;
+							writefln("write to offset: %d", offset);
 						}
+						pixel <<= 1;
 					}
 
 				}
@@ -971,18 +977,6 @@ struct Chip8 {
 
 	} // tick
 
-	void draw() {
-		
-		if (draw_flag) {
-			// update buffer with new pixel data
-			draw_flag = false;
-		}
-
-		// glPixelZoom(rt.width / 64, rt.height / 32);
-		// glDrawPixels(64, 32, GL_RGB, GL_UNSIGNED_BYTE, screen_data.ptr);
-
-	} // draw
-
 } // Emulator
 
 void loadLibs() {
@@ -1046,7 +1040,7 @@ struct Emulator {
 		emu.screen_buf[64*32 - 64] = 1;
 		emu.screen_buf[64*32 - 1] = 1;
 
-		// set up pixel buffer to poke a
+		// set up pixel buffer to poke at
 		buf.create(emu.screen_buf.ptr, 64, 32);
 
 	}
@@ -1100,6 +1094,7 @@ struct Emulator {
 		window.windowSize(w, h);
 		if (emu.draw_flag) {
 			buf.update(emu.screen_buf);
+			emu.draw_flag = false;
 		}
 		buf.draw(w, h);