diff --git a/cpu.js b/cpu.js
index abe7cb3..832f580 100644
--- a/cpu.js
+++ b/cpu.js
@@ -10,7 +10,7 @@ const {
 
 const {
   num2hex,
-  num2bin_4bit,
+  bool2bit,
 } = require('./logging.js');
 const display = require('./display.js');
 
@@ -19,8 +19,8 @@ const CPU = {
   // Core state
   running: false,
   IP: INITIAL_IP_ADDRESS,
-  FLAGS: 0, // A bit field! 0000 = ONZC
-  FlagNames: ['C', 'Z', 'N', 'O'],
+  FLAGS: {'C': false, 'Z': false, 'N': false, 'O': false},
+  FLAGNUMS2NAMES: {0: 'C', 1: 'Z', 2: 'N', 3: 'O'},
   Acc: 0,
   memory: null,
 
@@ -38,24 +38,8 @@ const CPU = {
     CPU.previousIP = CPU.IP;
     CPU.IP = address;
   },
-  setFlagOverflow: () => { CPU.FLAGS |= 4 },
-  setFlagNegative: () => { CPU.FLAGS |= 4 },
-  setFlagZero:     () => { CPU.FLAGS |= 2 },
-  setFlagCarry:    () => { CPU.FLAGS |= 1 },
-  unsetFlagOverflow: () => { CPU.FLAGS &= ~8 },
-  unsetFlagNegative: () => { CPU.FLAGS &= ~4 },
-  unsetFlagZero:     () => { CPU.FLAGS &= ~2 },
-  unsetFlagCarry:    () => { CPU.FLAGS &= ~1 },
-  updateFlagZero: () => {
-    if (CPU.Acc === 0) {
-      CPU.setFlagZero();
-    } else {
-      CPU.unsetFlagZero();
-    }
-  },
-  updateFlagNegative: () => {
-    CPU.Acc & 128 ? CPU.setFlagNegative : CPU.unsetFlagNegative
-  },
+  updateFlagZero: () => { CPU.FLAGS.Z = CPU.Acc === 0; },
+  updateFlagNegative: () => { CPU.Acc & 128 ? CPU.FLAGS.N = true : CPU.FLAGS.N = false },
 
   // Debug info
   previousIP: 0,
@@ -110,19 +94,22 @@ const Instructions = {
     // Calculate sum
     let sum = CPU.Acc + lit;
     if (sum > 255) {
-      CPU.setFlagCarry();
+      CPU.FLAGS.C = true;
       sum = (sum % 255) - 1;
     } else {
-      CPU.unsetFlagCarry();
+      CPU.FLAGS.C = false;
     }
     // Calculate overflow flag status
     let bitSixCarry = 0;
     if ((CPU.Acc & 64) && (lit & 64)) { bitSixCarry = 1; }
-    let overflow = bitSixCarry ^ (CPU.FLAGS & 8);
+    // let overflow = bitSixCarry ^ (CPU.FLAGS & 8);
+    // FIXME FIXME FIXME
+    // I'm on a plane and can't remember how this works
+    let overflow = 0;
     if (overflow) {
-      CPU.setFlagOverflow();
+      CPU.FLAGS.O = true;
     } else {
-      CPU.unsetFlagOverflow();
+      CPU.FLAGS.O = false;
     }
     CPU.Acc = sum;
     CPU.updateFlagNegative();
@@ -135,19 +122,22 @@ const Instructions = {
     // Calculate sum
     let sum = CPU.Acc + CPU.memory[addr];
     if (sum > 255) {
-      CPU.setFlagCarry();
+      CPU.FLAGS.C = true;
       sum = (sum % 255) - 1;
     } else {
-      CPU.unsetFlagCarry();
+      CPU.FLAGS.C = false;
     }
     // Calculate overflow flag status
     let bitSixCarry = 0;
     if ((CPU.Acc & 64) && (addr & 64)) { bitSixCarry = 1; }
-    let overflow = bitSixCarry ^ (CPU.FLAGS & 8);
+    // let overflow = bitSixCarry ^ (CPU.FLAGS & 8);
+    // FIXME FIXME FIXME
+    // I'm on a plane and can't remember how this works
+    let overflow = 0;
     if (overflow) {
-      CPU.setFlagOverflow();
+      CPU.FLAGS.O = true;
     } else {
-      CPU.unsetFlagOverflow();
+      CPU.FLAGS.O = false;
     }
     CPU.Acc = sum;
     CPU.updateFlagNegative();
@@ -160,19 +150,22 @@ const Instructions = {
     // Calculate sum
     let sum = CPU.Acc - lit;
     if (sum < 0) {
-      CPU.setFlagCarry();
+      CPU.FLAGS.C = true;
       sum = sum + 256;
     } else {
-      CPU.unsetFlagCarry();
+      CPU.FLAGS.C = false;
     }
     // Calculate overflow flag status
     let bitSixCarry = 0;
     if ((CPU.Acc & 64) && (lit & 64)) { bitSixCarry = 1; }
-    let overflow = bitSixCarry ^ (CPU.FLAGS & 8);
+    // let overflow = bitSixCarry ^ (CPU.FLAGS & 8);
+    // FIXME FIXME FIXME
+    // I'm on a plane and can't remember how this works
+    let overflow = 0;
     if (overflow) {
-      CPU.setFlagOverflow();
+      CPU.FLAGS.O = true;
     } else {
-      CPU.unsetFlagOverflow();
+      CPU.FLAGS.O = false;
     }
     CPU.Acc = sum;
     CPU.updateFlagNegative();
@@ -185,19 +178,22 @@ const Instructions = {
     // Calculate sum
     let sum = CPU.Acc - CPU.memory[addr];
     if (sum < 0) {
-      CPU.setFlagCarry();
+      CPU.FLAGS.C = true;
       sum = sum + 256;
     } else {
-      CPU.unsetFlagCarry();
+      CPU.FLAGS.C = false;
     }
     // Calculate overflow flag status
     let bitSixCarry = 0;
     if ((CPU.Acc & 64) && (addr & 64)) { bitSixCarry = 1; }
-    let overflow = bitSixCarry ^ (CPU.FLAGS & 8);
+    // let overflow = bitSixCarry ^ (CPU.FLAGS & 8);
+    // FIXME FIXME FIXME
+    // I'm on a plane and can't remember how this works
+    let overflow = 0;
     if (overflow) {
-      CPU.setFlagOverflow();
+      CPU.FLAGS.O = true;
     } else {
-      CPU.unsetFlagOverflow();
+      CPU.FLAGS.O = false;
     }
     CPU.Acc = sum;
     CPU.updateFlagNegative();
@@ -234,26 +230,24 @@ const Instructions = {
   },
 
   flag_toggle: (flagNum) => {
-    CPU.currentInstruction.mnemonic = `FTG; ${CPU.FlagNames[flagNum]}`;
-    let mask = null;
-    if (flagNum === 0) { mask = 1; }
-    if (flagNum === 1) { mask = 2; }
-    if (flagNum === 2) { mask = 8; }
-    if (flagNum === 3) { mask = 16; }
-    if (mask === null) { throw new Error('Invalid flag number'); }
-    CPU.FLAGS = CPU.FLAGS ^= mask;
+    if (flagNum === null) {
+      console.error('Invalid flag number');
+      process.exit();
+    }
+    const flagName = CPU.FLAGNUMS2NAMES[flagNum];
+    CPU.currentInstruction.mnemonic = `FTG ${flagName}`;
+    CPU.FLAGS[flagName] = !CPU.FLAGS[flagName];
     CPU.incrementIP(2);
   },
 
   flag_hop: (flagNum) => {
-    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 = 8; }
-    if (flagNum === 3) { mask = 16; }
-    if (mask === null) { throw new Error('Invalid flag number'); }
-    if (CPU.FLAGS & mask) {
+    if (flagNum === null) {
+      console.error('Invalid flag number');
+      process.exit();
+    }
+    const flagName = CPU.FLAGNUMS2NAMES[flagNum];
+    CPU.currentInstruction.mnemonic = `FHP ${flagName}; IP+2: ${CPU.memory[CPU.IP+2]}, IP+3: ${CPU.memory[CPU.IP+3]}`;
+    if (CPU.FLAGS[CPU.FLAGNUMS2NAMES[flagNum]]) {
       CPU.incrementIP(4);
     } else {
       CPU.incrementIP(2);
@@ -373,7 +367,11 @@ exports.runProgram =
       // Animate the output by pausing between steps
       const loop = setInterval(async () => {
         stepCPU(debugInfo, debug, prettyPrint);
-        if (!CPU.running) process.exit();
+        if (!CPU.running) {
+          logCPUState(debugInfo, debug, prettyPrint);
+          console.log('Halted');
+          process.exit();
+        }
       }, clockSpeed);
     }
   };
@@ -412,12 +410,12 @@ function logCPUState(debugInfo, debug = false, prettyPrintDisplay = false) {
     console.log();
     if (debugInfo) {
       console.log(`Line ${debugInfo.lineNumber}: ${debugInfo.source}`);
-    console.log();
+      console.log();
     }
     console.log('Mnemonic:', CPU.currentInstruction.mnemonic);
     console.log(`Machine:  $${num2hex(CPU.currentInstruction.opcode)} $${num2hex(CPU.currentInstruction.operand)}`);
     console.log();
-    console.log(`IP: $${num2hex(CPU.IP)}  Acc: $${num2hex(CPU.Acc)}  ONZC: ${num2bin_4bit(CPU.FLAGS)}`);
+    console.log(`IP: $${num2hex(CPU.IP)}  Acc: $${num2hex(CPU.Acc)}  ONZC ${bool2bit(CPU.FLAGS.O)}${bool2bit(CPU.FLAGS.N)}${bool2bit(CPU.FLAGS.Z)}${bool2bit(CPU.FLAGS.C)}`);
     console.log(`KEY: $${num2hex(CPU.memory[KEYPAD_ADDR])}  ${CPU.running ? "running" : "halted" }`);
     console.log();
     console.log();
diff --git a/logging.js b/logging.js
index a662a71..39ee03e 100644
--- a/logging.js
+++ b/logging.js
@@ -72,6 +72,12 @@ const num2bin_4bit = (num) => (num >>> 0).toString(2).padStart(4, "0");
  */
 const bin2num = (bin) => parseInt(bin, 2)
 
+/**
+ * @param {Boolean} bool
+ * @returns {0|1}
+ **/
+const bool2bit = (bool) => bool ? 1 : 0;
+
 
 module.exports = {
   "logMemory": logMemory,
@@ -81,4 +87,5 @@ module.exports = {
   "num2bin": num2bin,
   "num2bin_4bit": num2bin_4bit,
   "bin2num": bin2num,
+  "bool2bit": bool2bit,
 }
\ No newline at end of file