diff --git a/cpu.js b/cpu.js
index 56b3370..31e458b 100644
--- a/cpu.js
+++ b/cpu.js
@@ -20,6 +20,7 @@ const CPU = {
   running: false,
   IP: INITIAL_IP_ADDRESS,
   FLAGS: 0, // A bit field! 0000 = ONZC
+  FlagNames: ['C', 'Z', 'N', 'O'],
   Acc: 0,
   memory: null,
 
@@ -233,24 +234,24 @@ const Instructions = {
   },
 
   flag_toggle: (flagNum) => {
-    CPU.currentInstruction.mnemonic = 'FTG';
+    CPU.currentInstruction.mnemonic = `FTG; ${CPU.FlagNames[flagNum]}`;
     let mask = null;
     if (flagNum === 0) { mask = 1; }
     if (flagNum === 1) { mask = 2; }
-    if (flagNum === 2) { mask = 4; }
-    if (flagNum === 3) { mask = 8; }
+    if (flagNum === 2) { mask = 8; }
+    if (flagNum === 3) { mask = 16; }
     if (mask === null) { throw new Error('Invalid flag number'); }
     CPU.FLAGS = CPU.FLAGS ^= mask;
     CPU.incrementIP(2);
   },
 
   flag_hop: (flagNum) => {
-    CPU.currentInstruction.mnemonic = `FHP; IP+2: ${CPU.memory[CPU.IP+2]}, IP+3: ${CPU.memory[CPU.IP+3]}`;
+    CPU.currentInstruction.mnemonic = `FTG; ${CPU.FlagNames[flagNum]}; IP+2: ${CPU.memory[CPU.IP+2]}, IP+3: ${CPU.memory[CPU.IP+3]}`;
     let mask = null;
     if (flagNum === 0) { mask = 1; }
     if (flagNum === 1) { mask = 2; }
-    if (flagNum === 2) { mask = 4; }
-    if (flagNum === 3) { mask = 8; }
+    if (flagNum === 2) { mask = 8; }
+    if (flagNum === 3) { mask = 16; }
     if (mask === null) { throw new Error('Invalid flag number'); }
     if (CPU.FLAGS & mask) {
       CPU.incrementIP(4);