diff --git a/src/chip8.c b/src/chip8.c
new file mode 100644
index 0000000..dc733b0
--- /dev/null
+++ b/src/chip8.c
@@ -0,0 +1,247 @@
+#include "chip8.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+const uint8_t fontset[80] = {
+  0xF0, 0x90, 0x90, 0x90, 0xF0, // 0
+  0x20, 0x60, 0x20, 0x20, 0x70, // 1
+  0xF0, 0x10, 0xF0, 0x80, 0xF0, // 2
+  0xF0, 0x10, 0xF0, 0x10, 0xF0, // 3
+  0x90, 0x90, 0xF0, 0x10, 0x10, // 4
+  0xF0, 0x80, 0xF0, 0x10, 0xF0, // 5
+  0xF0, 0x80, 0xF0, 0x90, 0xF0, // 6
+  0xF0, 0x10, 0x20, 0x40, 0x40, // 7
+  0xF0, 0x90, 0xF0, 0x90, 0xF0, // 8
+  0xF0, 0x90, 0xF0, 0x10, 0xF0, // 9
+  0xF0, 0x90, 0xF0, 0x90, 0x90, // A
+  0xE0, 0x90, 0xE0, 0x90, 0xE0, // B
+  0xF0, 0x80, 0x80, 0x80, 0xF0, // C
+  0xE0, 0x90, 0x90, 0x90, 0xE0, // D
+  0xF0, 0x80, 0xF0, 0x80, 0xF0, // E
+  0xF0, 0x80, 0xF0, 0x80, 0x80  // F
+};
+
+void chip8_init(chip_eight_t *chip) {
+  memset(chip, 0, sizeof(chip_eight_t));
+  chip->pc = PROGRAM_START;
+  chip->dt = 0;
+  chip->st = 0;
+  chip->waiting_for_key = false;
+
+  for (int i = 0; i < 80; i++) {
+    chip->memory[FONT_START + i] = fontset[i];
+  }
+}
+
+int chip8_load_rom(chip_eight_t *chip, const char *file_path) {
+  FILE *file_ptr = fopen(file_path, "rb");
+
+  if (file_ptr == NULL) {
+    return FILE_MISSING;
+  }
+
+  fseek(file_ptr, 0, SEEK_END);
+  int num_of_bytes = ftell(file_ptr);
+
+  int max_program_size = MEMORY_SIZE - PROGRAM_START;
+
+  if (num_of_bytes > max_program_size) {
+    fclose(file_ptr);
+    return PROGRAM_TOO_LARGE;
+  }
+
+  fseek(file_ptr, 0, SEEK_SET);
+
+  size_t bytes_read = fread(&chip->memory[PROGRAM_START], sizeof(uint8_t), num_of_bytes, file_ptr);
+  (void)bytes_read; // Ignore unused warning
+  
+  fclose(file_ptr);
+
+  return COMPLETED_SUCCESSFULLY;
+}
+
+static void draw_sprite(chip_eight_t *chip, uint16_t n, uint16_t x, uint16_t y) {
+  uint8_t x_coordinate = chip->V[x] % SCREEN_WIDTH;
+  uint8_t y_coordinate = chip->V[y] % SCREEN_HEIGHT;
+  chip->V[15] = 0;
+
+  for (int row = 0; row < n; row++) {
+    uint8_t sprite_byte = chip->memory[chip->I + row];
+
+    if ((y_coordinate + row) >= SCREEN_HEIGHT) {
+      break;
+    }
+
+    for (int col = 0; col < 8; col++) {
+      if ((x_coordinate + col) >= SCREEN_WIDTH) {
+        break;
+      }
+      
+      uint8_t sprite_pixel = sprite_byte & (128 >> col);
+      int sprite_screen_index = ((y_coordinate + row) * SCREEN_WIDTH) + (x_coordinate + col);
+      uint32_t *screen_pixel = &chip->display[sprite_screen_index];
+
+      if (sprite_pixel != 0) {
+        if (*screen_pixel == 1) {
+          chip->V[15] = 1;
+        }
+
+        *screen_pixel ^= 1;
+      }
+    }
+  }
+}
+
+void chip8_step(chip_eight_t *chip) {
+  if (chip->waiting_for_key) {
+    return;
+  }
+
+  uint16_t opcode = (chip->memory[chip->pc] << 8) | (chip->memory[chip->pc + 1]);
+  chip->pc += 2;
+  
+  uint16_t nnn = opcode & 4095;
+  uint8_t nn = opcode & 255;
+  uint16_t n = opcode & 15;
+  uint16_t x = (opcode & 3840) >> 8;
+  uint16_t y = (opcode & 240) >> 4;
+  uint16_t kk = opcode & 255;
+
+  switch(opcode & 61440) {
+    case OPCODE_GROUP_SYS_OR_RET: 
+      if (opcode == OPCODE_CLS) {
+        memset(chip->display, 0, sizeof(chip->display));
+      } else if (opcode == OPCODE_RET) {
+        chip->sc -= 1;
+        chip->pc = chip->stack[chip->sc];
+      }
+      break;
+    case OPCODE_GROUP_JUMP:
+      chip->pc = nnn;
+      break;
+    case OPCODE_GROUP_CALL:
+      chip->stack[chip->sc] = chip->pc;
+      chip->sc += 1;
+      chip->pc = nnn;
+      break;
+    case OPCODE_GROUP_SE_VX_BYTE:
+      if (chip->V[x] == kk) {
+        chip->pc += 2;
+      }
+      break;
+    case OPCODE_GROUP_SNE_VX_BYTE:
+      if (chip->V[x] != kk) {
+        chip->pc += 2;
+      }
+      break;
+    case OPCODE_GROUP_SE_VX_VY:
+      if (chip->V[x] == chip->V[y]) {
+        chip->pc += 2;
+      }
+      break;
+    case OPCODE_GROUP_LD_VX_BYTE:
+      chip->V[x] = kk;
+      break;
+    case OPCODE_GROUP_ADD_VX_BYTE:
+      chip->V[x] += kk;
+      break;
+    case OPCODE_GROUP_ARITHMETIC:
+      if (n == SUB_OP_LD) {
+        chip->V[x] = chip->V[y];
+      } else if (n == SUB_OP_OR) {
+        chip->V[x] = chip->V[x] | chip->V[y];
+      } else if (n == SUB_OP_AND) {
+        chip->V[x] = chip->V[x] & chip->V[y];
+      } else if (n == SUB_OP_XOR) {
+        chip->V[x] = chip->V[x] ^ chip->V[y];
+      } else if (n == SUB_OP_ADD) {
+        uint16_t r = chip->V[x] + chip->V[y];
+        chip->V[15] = (r > 255) ? 1 : 0;
+        chip->V[x] = r & 255;
+      } else if (n == SUB_OP_SUB) {
+        chip->V[15] = (chip->V[x] >= chip->V[y]) ? 1 : 0;
+        chip->V[x] = chip->V[x] - chip->V[y];
+      } else if (n == SUB_OP_SHR) {
+        uint8_t flag = chip->V[x] & 1;
+        chip->V[15] = flag;
+        chip->V[x] /= 2;
+      } else if (n == SUB_OP_SUBN) {
+        chip->V[15] = (chip->V[y] >= chip->V[x]) ? 1 : 0;
+        chip->V[x] = chip->V[y] - chip->V[x];
+      } else if (n == SUB_OP_SHL) {
+        uint8_t flag = (chip->V[x] & 128) >> 7;
+        chip->V[15] = flag;
+        chip->V[x] *= 2;
+      }
+      break;
+    case OPCODE_GROUP_SNE_VX_VY:
+      if (chip->V[x] != chip->V[y]) {
+        chip->pc += 2;
+      }
+      break;
+    case OPCODE_GROUP_LD_I_ADDR:
+      chip->I = nnn;
+      break;
+    case OPCODE_GROUP_JP_V0_ADDR:
+      chip->pc = nnn + chip->V[0];
+      break;
+    case OPCODE_GROUP_RND_VX_BYTE:
+      uint8_t num = rand() % 256;
+      chip->V[x] = kk & num;
+      break;
+    case OPCODE_GROUP_DRW_VX_VY_N:
+      draw_sprite(chip, n, x, y);
+      break;
+    case OPCODE_GROUP_KEY_SKIP:
+      if (nn == OPCODE_SKP) {
+        if (chip->keys[chip->V[x] & 0x0F] == 1) {
+          chip->pc += 2;
+        }
+      } else if (nn == OPCODE_SKNP) {
+        if (chip->keys[chip->V[x] & 0x0F] != 1) {
+          chip->pc += 2;
+        }
+      }
+      break;
+    case OPCODE_GROUP_MISC:
+      if (nn == SUB_OP_LD_VX_DT) {
+        chip->V[x] = chip->dt;
+      } else if (nn == SUB_OP_LD_VX_K) {
+        chip->waiting_for_key = true;
+        chip->key_register = x;
+      } else if (nn == SUB_OP_LD_DT_VX) {
+        chip->dt = chip->V[x];
+      } else if (nn == SUB_OP_LD_ST_VX) {
+        chip->st = chip->V[x];
+      } else if (nn == SUB_OP_ADD_I_VX) {
+        chip->I += chip->V[x];
+      } else if (nn == SUB_OP_LD_F_VX) {
+        chip->I = FONT_START + ((chip->V[x] & 0x0F) * 5);
+      } else if (nn == SUB_OP_LD_B_VX) {
+        chip->memory[chip->I] = chip->V[x] / 100;
+        chip->memory[chip->I + 1] = (chip->V[x] / 10) % 10;
+        chip->memory[chip->I + 2] = chip->V[x] % 10;
+      } else if (nn == SUB_OP_LD_I_REG) {
+        for (int i = 0; i <= x; i++) {
+          chip->memory[chip->I + i] = chip->V[i];
+        }
+      } else if (nn == SUB_OP_LD_REG_I) {
+        for (int i = 0; i <= x; i++) {
+          chip->V[i] = chip->memory[chip->I + i];
+        }
+      }
+      break;
+    default:
+      break;
+  }
+}
+
+void chip8_tick_timers(chip_eight_t *chip) {
+  if (chip->dt > 0) {
+    chip->dt--;
+  }
+  if (chip->st > 0) {
+    chip->st--;
+  }
+}