implement SUB Vx, Vy

1 files changed, 5 insertions, 0 deletions

diff --git a/src/chip8.rs b/src/chip8.rs
index 248c302..a172fa6 100644
--- a/src/chip8.rs
+++ b/src/chip8.rs
@@ -130,6 +130,11 @@ impl Chip8 {
                     self.v[0xF] = if v > 255 { 1 } else { 0 };
                     self.v[x] = v as u8;
                 }
+                0x0005 => {
+                    eprintln!("SUB V{}, V{}", x, y);
+                    self.v[0xF] = if self.v[x] > self.v[y] { 1 } else { 0 };
+                    self.v[x] = self.v[x].wrapping_sub(self.v[y]);
+                }
                 _ => unknown_opcode(opcode),
             },
             0x9000 => {