Update src/opcode.rs

src/opcode.rs

@@ -16,8 +16,7 @@ pub enum Opcode {
     LBL    = 0x72,
     VCAST  = 0x80,
     VWEI   = 0x81,
-    MSND   = 0x90,
-    MRCV   = 0x91,
+    SIM    = 0x90,
     HALT   = 0xA0,
     NOOP   = 0xA1,
 }
@@ -42,8 +41,7 @@ impl Opcode {
             0x72 => LBL,
             0x80 => VCAST,
             0x81 => VWEI,
-            0x90 => MSND,
-            0x91 => MRCV,
+            0x90 => SIM,
             0xA0 => HALT,
             0xA1 => NOOP,
             _ => return None,