diff --git a/makefile b/makefile
index d821024..c99007c 100644
--- a/makefile
+++ b/makefile
@@ -2,10 +2,10 @@ SDL_CFLAGS = `sdl2-config --cflags`
 SDL_LDFLAGS = `sdl2-config --libs`
 
 lint:
-	verilator --lint-only --timing yayacemu.sv rom_loader.sv
+	verilator --lint-only --timing *.sv
 
 build: lint
-	verilator --cc --exe --build --timing -j 0 yayacemu.sv rom_loader.sv yayacemu.cpp -CFLAGS "${SDL_CFLAGS}" -LDFLAGS "${SDL_LDFLAGS}" && clear
+	verilator --cc --exe --build --timing -j 0 --top-module yayacemu *.sv yayacemu.cpp -CFLAGS "${SDL_CFLAGS}" -LDFLAGS "${SDL_LDFLAGS}" && clear
 
 run: build
 	obj_dir/Vyayacemu ${ROM_FILE}	
diff --git a/yayacemu.cpp b/yayacemu.cpp
index 7465205..735c0cb 100644
--- a/yayacemu.cpp
+++ b/yayacemu.cpp
@@ -37,15 +37,18 @@ void init_screen() {
   printf("INF_EMU: Screen initialized\n");
 }
 
-void draw_screen(const svLogicVecVal* vram, const svBit beep) {
-  uint32_t *screen = (uint32_t*) malloc(SCREEN_WIDTH*SCREEN_HEIGHT*32);
-  for(int i = 0; i < SCREEN_WIDTH * SCREEN_HEIGHT; i++) {
-      screen[i] = vram[i].aval;
-  }
+void set_beep(const svBit beep) {
   if (beep > 0)
       SDL_SetTextureColorMod(texture, 255, 0, 0);
   else
       SDL_SetTextureColorMod(texture, 255, 255, 255);
+}
+
+void draw_screen(const svLogicVecVal* vram) {
+  uint32_t *screen = (uint32_t*) malloc(SCREEN_WIDTH*SCREEN_HEIGHT*32);
+  for(int i = 0; i < SCREEN_WIDTH * SCREEN_HEIGHT; i++) {
+      screen[i] = vram[i].aval;
+  }
   SDL_UpdateTexture(texture, NULL, screen,
                         sizeof(screen[0]) * SCREEN_WIDTH);
   SDL_RenderClear(renderer);
diff --git a/yayacemu.sv b/yayacemu.sv
index 5ba46ba..a1a180e 100644
--- a/yayacemu.sv
+++ b/yayacemu.sv
@@ -1,8 +1,6 @@
 module yayacemu (
     input wire clk_in
     );
-    import "DPI-C" function void init_screen();
-
     wire [31:0] vram [0:2047];
     bit [7:0] memory [0:4095];
     wire [7:0] registers [0:15];
@@ -25,8 +23,9 @@ module yayacemu (
     randomizer randy(clk_in, program_counter, keyboard, cycle_counter, rand_num);
     keyboard kb(clk_in, keyboard);
     rom_loader rl (memory, rom_ready);
-    chip8_cpu cpu (memory, clk_in, keyboard, rand_num, vram, stack, index_reg, stack_pointer, registers, delay_timer, sound_timer, cycle_counter, program_counter, halt, watch_key);
-    chip8_gpu gpu (vram, sound_timer);
+    cpu cpu (memory, clk_in, keyboard, rand_num, vram, stack, index_reg, stack_pointer, registers, delay_timer, sound_timer, cycle_counter, program_counter, halt, watch_key);
+    beeper beeper(sound_timer);
+    gpu gpu (vram);
 
     int i;
     initial begin 
@@ -61,349 +60,6 @@ module yayacemu (
         cycle_counter = 0;
         program_counter = 'h200;
         stack_pointer = 4'b0000;
-        init_screen();
     end
 
 endmodule
-
-module keyboard (
-    input wire clk_in,
-    output bit keyboard [15:0]
-    );
-    int i;
-    import "DPI-C" function bit [7:0] get_key();
-    bit[7:0] keyval;
-    always_ff @(posedge clk_in) begin
-        keyval = get_key();
-        if (keyval != 8'b11111111) begin
-           keyboard[keyval[3:0]] = keyval[7]; 
-        end
-    end
-endmodule
-
-module chip8_cpu(
-    output bit [7:0] memory [0:4095],
-    input wire clk_in,
-    input wire keyboard [15:0],
-    input wire [7:0] random_number,
-    output wire [31:0] vram [0:2047],
-    output wire [15:0] stack [0:15],
-    output wire [15:0] index_reg,
-    output wire [3:0] stack_pointer,
-    output wire [7:0] registers [0:15],
-    output logic [7:0] delay_timer,
-    output logic [7:0] sound_timer,
-    output int cycle_counter,
-    output wire [15:0] program_counter,
-    output bit halt,
-    output int watch_key
-    );
-
-    logic [15:0] opcode;
-
-    logic [15:0] scratch;
-    logic [15:0] scratch2;
-
-    logic [7:0] scratch_8;
-    logic [7:0] scratch_82;
-
-    logic [31:0] x_cord;
-    logic [31:0] y_cord;
-    logic [7:0] size;
-    logic [31:0] screen_pixel;
-    logic [7:0] sprite_pixel;
-
-    int i;
-    logic [7:0] i8;
-
-    int r;
-    int c;
-    always_ff @(posedge clk_in) begin
-        opcode = {memory[program_counter+0],  memory[program_counter+1]};
-        $display("HW     : opcode is 0x%h (%b)", opcode, opcode);
-        $display("HW     : PC %0d 0x%h", program_counter, program_counter);
-
-        // 480Hz / 8 = 60 Hz
-        if (cycle_counter % 20 == 0) begin
-            if (delay_timer > 0)
-                delay_timer--;
-            if (sound_timer > 0)
-                sound_timer--;
-        end
-
-        casez(opcode)
-            'h00E0: begin 
-                $display("HW     : INSTR CLS");
-                for(i = 0; i < 2048; i++) begin
-                    vram[i] = 0;
-                end
-            end
-            'h00EE: begin
-               $display("HW     : INSTR RET"); 
-               stack_pointer--;
-               program_counter = stack[stack_pointer];
-            end
-            'h0???: $display("HW     : INSTR SYS addr (Treating as NOP)");
-            'h1???: begin 
-                $display("HW     : INSTR JP addr");
-                program_counter = (opcode & 'h0FFF) - 2;
-            end
-            'h2???: begin
-                $display("HW     : INSTR CALL addr");
-                stack[stack_pointer] = program_counter;
-                stack_pointer++;
-                program_counter = (opcode & 'h0FFF) - 2;
-            end 
-            'h3???: begin
-                $display("HW     : INSTR SE Vx, byte");
-                scratch = (opcode & 'h00FF);
-                if (scratch[7:0] == registers[(opcode & 'h0F00) >> 8]) begin
-                    program_counter += 2;
-                end
-            end
-            'h4???: begin
-                $display("HW     : INSTR SNE Vx, byte");
-                scratch = (opcode & 'h00FF);
-                if (scratch[7:0] != registers[(opcode & 'h0F00) >> 8]) begin
-                    program_counter += 2;
-                end
-            end
-            'h5??0: begin
-                $display("HW     : INSTR SE Vx, Vy");
-                if (registers[(opcode & 'h00F0) >> 4] == registers[(opcode & 'h0F00) >> 8]) begin
-                    program_counter += 2;
-                end
-            end
-            'h6???: begin
-                $display("HW     : INSTR LD Vx, byte");
-                scratch = (opcode & 'h00FF);
-                registers[(opcode & 'h0F00) >> 8] = scratch[7:0];
-            end
-            'h7???: begin
-                $display("HW     : INSTR ADD Vx, byte");
-                scratch = (opcode & 'h00FF);
-                registers[(opcode & 'h0F00) >> 8] += scratch[7:0];
-            end
-            'h8??0: begin
-                $display("HW     : INSTR LD Vx, Vy");
-                registers[(opcode & 'h0F00) >> 8] = registers[(opcode & 'h00F0) >> 4];
-            end
-            'h8??1: begin
-                $display("HW     : INSTR OR Vx, Vy");
-                registers[(opcode & 'h0F00) >> 8] |= registers[(opcode & 'h00F0) >> 4];
-                registers[15] = 0;
-            end
-            'h8??2: begin
-                $display("HW     : INSTR AND Vx, Vy");
-                registers[(opcode & 'h0F00) >> 8] &= registers[(opcode & 'h00F0) >> 4];
-                registers[15] = 0;
-            end
-            'h8??3: begin
-                $display("HW     : INSTR XOR Vx, Vy");
-                registers[(opcode & 'h0F00) >> 8] ^= registers[(opcode & 'h00F0) >> 4];
-                registers[15] = 0;
-            end
-            'h8??4: begin
-                $display("HW     : INSTR ADD Vx, Vy");
-                scratch_8 = registers[(opcode & 'h0F00) >> 8];
-                registers[(opcode & 'h0F00) >> 8] += registers[(opcode & 'h00F0) >> 4];
-                registers[15] = {7'b0000000, scratch_8 > registers[(opcode & 'h0F00) >> 8]};
-            end
-            'h8??5: begin
-                $display("HW     : INSTR SUB Vx, Vy");
-                scratch_8 = registers[(opcode & 'h0F00) >> 8];
-                registers[(opcode & 'h0F00) >> 8] -= registers[(opcode & 'h00F0) >> 4];
-                registers[15] = {7'b0000000, scratch_8 >= registers[(opcode & 'h0F00) >> 8]};
-            end
-            'h8??6: begin
-                $display("HW     : INSTR SHR Vx {, Vy}");
-                scratch_8 = registers[(opcode & 'h0F00) >> 8];
-                registers[(opcode & 'h0F00) >> 8] = registers[(opcode & 'h00F0) >> 4]>> 1;
-                registers[15] = {7'b0000000,  ((scratch_8 & 8'h01) == 8'h01)};
-            end
-            'h8??7: begin
-                $display("HW     : INSTR SUBN Vx, Vy");
-                scratch_8 = registers[(opcode & 'h00F0) >> 4];
-                scratch_82 = registers[(opcode & 'h0F00) >> 8];
-                registers[(opcode & 'h0F00) >> 8] = registers[(opcode & 'h00F0) >> 4] - registers[(opcode & 'h0F00) >> 8];
-                registers[15] = {7'b0000000, (scratch_8 >= scratch_82)};
-            end
-            'h8??E: begin
-                $display("HW     : INSTR SHL Vx {, Vy}");
-                scratch_8 = registers[(opcode & 'h0F00) >> 8];
-                registers[(opcode & 'h0F00) >> 8] = registers[(opcode & 'h00F0) >> 4]<< 1;
-
-                registers[15] = {7'b0000000, (scratch_8[7]) };
-            end
-            'h9??0: begin
-                $display("HW     : INSTR SNE Vx, Vy");
-                if (registers[(opcode & 'h00F0) >> 4] != registers[(opcode & 'h0F00) >> 8]) begin
-                    program_counter += 2;
-                end
-            end
-            'hA???: begin
-                $display("HW     : INSTR LD I, addr");
-                index_reg = (opcode & 'h0FFF);
-            end
-            'hb???: begin
-                $display("HW     : INSTR JP V0, addr");
-                program_counter = {8'h00, registers[0]} + (opcode & 'h0FFF) - 2;
-            end
-            'hc???: begin
-                $display("HW     : RND Vx, addr");
-                // TODO: use a real RNG module, this is not synthesizeable
-                scratch = {8'h00, random_number} % 16'h0100;
-                scratch2 = (opcode & 'h00FF);
-                registers[(opcode & 'h0F00) >> 8] = scratch[7:0] & scratch2[7:0];
-            end
-            'hD???: begin
-                if (cycle_counter % 20 != 0) begin
-                    halt = 1;
-                end else begin
-                    halt = 0;
-                $display("HW     : INSTR DRW Vx, Vy, nibble");
-                x_cord = {24'h000000, registers[(opcode & 'h0F00) >> 8]};
-                y_cord = {24'h000000, registers[(opcode & 'h00F0) >> 4]};
-
-                x_cord %= 64;
-                y_cord %= 32;
-
-                scratch = (opcode & 'h000F);
-                size = scratch[7:0];
-                registers[15] = 0;
-
-                for (r = 0; r < size; r++) begin 
-                    for ( c = 0; c < 8; c++) begin 
-                        if (r + y_cord >= 32 || x_cord + c >= 64)
-                            continue;
-                        screen_pixel = vram[((r + y_cord) * 64) + (x_cord + c)];
-                        sprite_pixel = memory[{16'h0000, index_reg} + r] & ('h80 >> c);
-        
-                        if (|sprite_pixel) begin 
-                           if (screen_pixel == 32'hFFFFFFFF) begin 
-                                registers[15] = 1;
-                           end 
-                           vram[((r + y_cord) * 64) + (x_cord + c)] ^= 32'hFFFFFFFF;
-                        end 
-                  end 
-                end
-            end
-            end
-            'hE?9E: begin
-                $display("HW     : INSTR SKP Vx");
-                if (keyboard[{registers[(opcode & 'h0F00) >> 8]}[3:0]] == 1) begin
-                    program_counter += 2;
-                end
-            end
-            'hE?A1: begin
-                $display("HW     : INSTR SNE Vx");
-                if (keyboard[{registers[(opcode & 'h0F00) >> 8]}[3:0]] != 1) begin
-                    program_counter += 2;
-                end
-            end
-            'hF?07: begin
-                $display("HW     : INSTR LD Vx, DT");
-                registers[(opcode & 'h0F00) >> 8] = delay_timer;
-            end
-            'hF?0A: begin
-                $display("HW     : INSTR LD Vx, K");
-                halt = 1;
-                for(i = 0; i < 16; i++) begin
-                    if (watch_key == 255) begin
-                        if (keyboard[i]) begin
-                           watch_key = i; 
-                        end
-                    end else begin
-                        if (!keyboard[watch_key]) begin
-                            halt = 0;
-                            watch_key = 255;
-                        end
-                    end
-                end
-            end
-            'hF?15: begin
-                $display("HW     : INSTR LD DT, Vx");
-               delay_timer =  registers[(opcode & 'h0F00) >> 8];
-            end
-            'hF?18: begin
-                $display("HW     : INSTR LD ST, Vx");
-               sound_timer =  registers[(opcode & 'h0F00) >> 8];
-            end
-            'hF?1E: begin
-                $display("HW     : INSTR ADD I, Vx");
-                index_reg = index_reg + {8'h00, registers[(opcode & 'h0F00) >> 8]};
-            end
-            'hF?29: begin
-                $display("HW     : INSTR LDL F, Vx");
-                index_reg = registers[(opcode & 'h0F00) >> 8] * 5;
-            end
-            'hF?33: begin
-               $display("HW     : INSTR LD B, Vx"); 
-                scratch = {8'h00, registers[(opcode & 'h0F00) >> 8]};
-                scratch2 = scratch % 10;
-                memory[index_reg + 2] = scratch2[7:0];
-                scratch /= 10;
-                scratch2 = scratch % 10;
-                memory[index_reg + 1] = scratch2[7:0];
-                scratch /= 10;
-                scratch2 = scratch % 10;
-                memory[index_reg + 0] = scratch2[7:0];
-            end
-            'hF?55: begin
-               $display("HW     : INSTR LD [I], Vx"); 
-                scratch = (opcode & 'h0F00) >> 8;
-                for (i8 = 0; i8 <= scratch[7:0]; i8++) begin 
-                  scratch2 = index_reg + {8'h00, i8};
-                  memory[scratch2[11:0]] = registers[i8[3:0]];
-                end 
-                index_reg++;
-            end
-            'hF?65: begin
-                $display("HW     : INSTR LD Vx, [I]");
-                scratch = (opcode & 'h0F00) >> 8;
-                for (i8 = 0; i8 <= scratch[7:0]; i8++) begin 
-                  scratch2 = index_reg + {8'h00, i8};
-                  registers[i8[3:0]] = memory[scratch2[11:0]];
-                end 
-                index_reg++;
-            end
-            default: $display("HW     : ILLEGAL INSTRUCTION");
-        endcase
-        if (!halt) 
-            program_counter += 2;
-        cycle_counter++;
-    end
-endmodule
-
-// pseudo random number generator
-module randomizer (
-    input wire clk_in,
-    input wire [15:0] pc,
-    input bit keyboard [15:0],
-    input int cycle_counter,
-    output bit [7:0] rand_bit
-    );
-
-    bit [7:0] last;
-    int i;
-    
-    always_ff @(posedge clk_in) begin
-        for (i = 0; i < 8; i++) begin
-            rand_bit[i] ^= ~keyboard[i] ? cycle_counter[i] : cycle_counter[7-i];
-            rand_bit[i] ^= (cycle_counter % 7) == 0 ? pc[i] : ~pc[i];
-            rand_bit[i] ^= keyboard[i+7] ? ~last[i] : last[i];
-        end 
-        last = rand_bit;
-        $display("Randomizer is: %b", rand_bit);
-    end
-endmodule
-
-module chip8_gpu (
-    input wire [31:0] vram [0:2047],
-    input wire [7:0] sound_timer
-    );
-    import "DPI-C" function void draw_screen(logic [31:0] vram [0:2047], bit beep);
-    always_comb begin
-       draw_screen(vram, sound_timer > 0); 
-    end
-endmodule