diff --git a/src/Terminal.ts b/src/Terminal.ts
index 9f396af0..1b7a0c1a 100644
--- a/src/Terminal.ts
+++ b/src/Terminal.ts
@@ -51,34 +51,7 @@ import { ITheme, ILocalizableStrings, IMarker, IDisposable } from 'xterm';
 import { removeTerminalFromCache } from './renderer/atlas/CharAtlasCache';
 import { DomRenderer } from './renderer/dom/DomRenderer';
 import { IKeyboardEvent } from './base/Types';
-
-// reg + shift key mappings for digits and special chars
-const KEYCODE_KEY_MAPPINGS: { [key: number]: [string, string]} = {
-  // digits 0-9
-  48: ['0', ')'],
-  49: ['1', '!'],
-  50: ['2', '@'],
-  51: ['3', '#'],
-  52: ['4', '$'],
-  53: ['5', '%'],
-  54: ['6', '^'],
-  55: ['7', '&'],
-  56: ['8', '*'],
-  57: ['9', '('],
-
-  // special chars
-  186: [';', ':'],
-  187: ['=', '+'],
-  188: [',', '<'],
-  189: ['-', '_'],
-  190: ['.', '>'],
-  191: ['/', '?'],
-  192: ['`', '~'],
-  219: ['[', '{'],
-  220: ['\\', '|'],
-  221: [']', '}'],
-  222: ['\'', '"']
-};
+import { evaluateKeyboardEvent } from './core/input/Keyboard';
 
 // Let it work inside Node.js for automated testing purposes.
 const document = (typeof window !== 'undefined') ? window.document : null;
@@ -1449,7 +1422,7 @@ export class Terminal extends EventEmitter implements ITerminal, IDisposable, II
       return false;
     }
 
-    const result = this._evaluateKeyEscapeSequence(event);
+    const result = evaluateKeyboardEvent(event);
 
     // if (result.key === C0.DC3) { // XOFF
     //   this._writeStopped = true;
@@ -1496,329 +1469,6 @@ export class Terminal extends EventEmitter implements ITerminal, IDisposable, II
     return thirdLevelKey && (!ev.keyCode || ev.keyCode > 47);
   }
 
-  /**
-   * Returns an object that determines how a KeyboardEvent should be handled. The key of the
-   * returned value is the new key code to pass to the PTY.
-   *
-   * Reference: http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
-   * @param ev The keyboard event to be translated to key escape sequence.
-   */
-  protected _evaluateKeyEscapeSequence(ev: IKeyboardEvent): {cancel: boolean, key: string, scrollLines: number} {
-    const result: {cancel: boolean, key: string, scrollLines: number} = {
-      // Whether to cancel event propogation (NOTE: this may not be needed since the event is
-      // canceled at the end of keyDown
-      cancel: false,
-      // The new key even to emit
-      key: undefined,
-      // The number of characters to scroll, if this is defined it will cancel the event
-      scrollLines: undefined
-    };
-    const modifiers = (ev.shiftKey ? 1 : 0) | (ev.altKey ? 2 : 0) | (ev.ctrlKey ? 4 : 0) | (ev.metaKey ? 8 : 0);
-    switch (ev.keyCode) {
-      case 0:
-        if (ev.key === 'UIKeyInputUpArrow') {
-          if (this.applicationCursor) {
-            result.key = C0.ESC + 'OA';
-          } else {
-            result.key = C0.ESC + '[A';
-          }
-        }
-        else if (ev.key === 'UIKeyInputLeftArrow') {
-          if (this.applicationCursor) {
-            result.key = C0.ESC + 'OD';
-          } else {
-            result.key = C0.ESC + '[D';
-          }
-        }
-        else if (ev.key === 'UIKeyInputRightArrow') {
-          if (this.applicationCursor) {
-            result.key = C0.ESC + 'OC';
-          } else {
-            result.key = C0.ESC + '[C';
-          }
-        }
-        else if (ev.key === 'UIKeyInputDownArrow') {
-          if (this.applicationCursor) {
-            result.key = C0.ESC + 'OB';
-          } else {
-            result.key = C0.ESC + '[B';
-          }
-        }
-        break;
-      case 8:
-        // backspace
-        if (ev.shiftKey) {
-          result.key = C0.BS; // ^H
-          break;
-        } else if (ev.altKey) {
-          result.key = C0.ESC + C0.DEL; // \e ^?
-          break;
-        }
-        result.key = C0.DEL; // ^?
-        break;
-      case 9:
-        // tab
-        if (ev.shiftKey) {
-          result.key = C0.ESC + '[Z';
-          break;
-        }
-        result.key = C0.HT;
-        result.cancel = true;
-        break;
-      case 13:
-        // return/enter
-        result.key = C0.CR;
-        result.cancel = true;
-        break;
-      case 27:
-        // escape
-        result.key = C0.ESC;
-        result.cancel = true;
-        break;
-      case 37:
-        // left-arrow
-        if (modifiers) {
-          result.key = C0.ESC + '[1;' + (modifiers + 1) + 'D';
-          // HACK: Make Alt + left-arrow behave like Ctrl + left-arrow: move one word backwards
-          // http://unix.stackexchange.com/a/108106
-          // macOS uses different escape sequences than linux
-          if (result.key === C0.ESC + '[1;3D') {
-            result.key = (this.browser.isMac) ? C0.ESC + 'b' : C0.ESC + '[1;5D';
-          }
-        } else if (this.applicationCursor) {
-          result.key = C0.ESC + 'OD';
-        } else {
-          result.key = C0.ESC + '[D';
-        }
-        break;
-      case 39:
-        // right-arrow
-        if (modifiers) {
-          result.key = C0.ESC + '[1;' + (modifiers + 1) + 'C';
-          // HACK: Make Alt + right-arrow behave like Ctrl + right-arrow: move one word forward
-          // http://unix.stackexchange.com/a/108106
-          // macOS uses different escape sequences than linux
-          if (result.key === C0.ESC + '[1;3C') {
-            result.key = (this.browser.isMac) ? C0.ESC + 'f' : C0.ESC + '[1;5C';
-          }
-        } else if (this.applicationCursor) {
-          result.key = C0.ESC + 'OC';
-        } else {
-          result.key = C0.ESC + '[C';
-        }
-        break;
-      case 38:
-        // up-arrow
-        if (modifiers) {
-          result.key = C0.ESC + '[1;' + (modifiers + 1) + 'A';
-          // HACK: Make Alt + up-arrow behave like Ctrl + up-arrow
-          // http://unix.stackexchange.com/a/108106
-          if (result.key === C0.ESC + '[1;3A') {
-            result.key = C0.ESC + '[1;5A';
-          }
-        } else if (this.applicationCursor) {
-          result.key = C0.ESC + 'OA';
-        } else {
-          result.key = C0.ESC + '[A';
-        }
-        break;
-      case 40:
-        // down-arrow
-        if (modifiers) {
-          result.key = C0.ESC + '[1;' + (modifiers + 1) + 'B';
-          // HACK: Make Alt + down-arrow behave like Ctrl + down-arrow
-          // http://unix.stackexchange.com/a/108106
-          if (result.key === C0.ESC + '[1;3B') {
-            result.key = C0.ESC + '[1;5B';
-          }
-        } else if (this.applicationCursor) {
-          result.key = C0.ESC + 'OB';
-        } else {
-          result.key = C0.ESC + '[B';
-        }
-        break;
-      case 45:
-        // insert
-        if (!ev.shiftKey && !ev.ctrlKey) {
-          // <Ctrl> or <Shift> + <Insert> are used to
-          // copy-paste on some systems.
-          result.key = C0.ESC + '[2~';
-        }
-        break;
-      case 46:
-        // delete
-        if (modifiers) {
-          result.key = C0.ESC + '[3;' + (modifiers + 1) + '~';
-        } else {
-          result.key = C0.ESC + '[3~';
-        }
-        break;
-      case 36:
-        // home
-        if (modifiers) {
-          result.key = C0.ESC + '[1;' + (modifiers + 1) + 'H';
-        } else if (this.applicationCursor) {
-          result.key = C0.ESC + 'OH';
-        } else {
-          result.key = C0.ESC + '[H';
-        }
-        break;
-      case 35:
-        // end
-        if (modifiers) {
-          result.key = C0.ESC + '[1;' + (modifiers + 1) + 'F';
-        } else if (this.applicationCursor) {
-          result.key = C0.ESC + 'OF';
-        } else {
-          result.key = C0.ESC + '[F';
-        }
-        break;
-      case 33:
-        // page up
-        if (ev.shiftKey) {
-          result.scrollLines = -(this.rows - 1);
-        } else {
-          result.key = C0.ESC + '[5~';
-        }
-        break;
-      case 34:
-        // page down
-        if (ev.shiftKey) {
-          result.scrollLines = this.rows - 1;
-        } else {
-          result.key = C0.ESC + '[6~';
-        }
-        break;
-      case 112:
-        // F1-F12
-        if (modifiers) {
-          result.key = C0.ESC + '[1;' + (modifiers + 1) + 'P';
-        } else {
-          result.key = C0.ESC + 'OP';
-        }
-        break;
-      case 113:
-        if (modifiers) {
-          result.key = C0.ESC + '[1;' + (modifiers + 1) + 'Q';
-        } else {
-          result.key = C0.ESC + 'OQ';
-        }
-        break;
-      case 114:
-        if (modifiers) {
-          result.key = C0.ESC + '[1;' + (modifiers + 1) + 'R';
-        } else {
-          result.key = C0.ESC + 'OR';
-        }
-        break;
-      case 115:
-        if (modifiers) {
-          result.key = C0.ESC + '[1;' + (modifiers + 1) + 'S';
-        } else {
-          result.key = C0.ESC + 'OS';
-        }
-        break;
-      case 116:
-        if (modifiers) {
-          result.key = C0.ESC + '[15;' + (modifiers + 1) + '~';
-        } else {
-          result.key = C0.ESC + '[15~';
-        }
-        break;
-      case 117:
-        if (modifiers) {
-          result.key = C0.ESC + '[17;' + (modifiers + 1) + '~';
-        } else {
-          result.key = C0.ESC + '[17~';
-        }
-        break;
-      case 118:
-        if (modifiers) {
-          result.key = C0.ESC + '[18;' + (modifiers + 1) + '~';
-        } else {
-          result.key = C0.ESC + '[18~';
-        }
-        break;
-      case 119:
-        if (modifiers) {
-          result.key = C0.ESC + '[19;' + (modifiers + 1) + '~';
-        } else {
-          result.key = C0.ESC + '[19~';
-        }
-        break;
-      case 120:
-        if (modifiers) {
-          result.key = C0.ESC + '[20;' + (modifiers + 1) + '~';
-        } else {
-          result.key = C0.ESC + '[20~';
-        }
-        break;
-      case 121:
-        if (modifiers) {
-          result.key = C0.ESC + '[21;' + (modifiers + 1) + '~';
-        } else {
-          result.key = C0.ESC + '[21~';
-        }
-        break;
-      case 122:
-        if (modifiers) {
-          result.key = C0.ESC + '[23;' + (modifiers + 1) + '~';
-        } else {
-          result.key = C0.ESC + '[23~';
-        }
-        break;
-      case 123:
-        if (modifiers) {
-          result.key = C0.ESC + '[24;' + (modifiers + 1) + '~';
-        } else {
-          result.key = C0.ESC + '[24~';
-        }
-        break;
-      default:
-        // a-z and space
-        if (ev.ctrlKey && !ev.shiftKey && !ev.altKey && !ev.metaKey) {
-          if (ev.keyCode >= 65 && ev.keyCode <= 90) {
-            result.key = String.fromCharCode(ev.keyCode - 64);
-          } else if (ev.keyCode === 32) {
-            // NUL
-            result.key = String.fromCharCode(0);
-          } else if (ev.keyCode >= 51 && ev.keyCode <= 55) {
-            // escape, file sep, group sep, record sep, unit sep
-            result.key = String.fromCharCode(ev.keyCode - 51 + 27);
-          } else if (ev.keyCode === 56) {
-            // delete
-            result.key = String.fromCharCode(127);
-          } else if (ev.keyCode === 219) {
-            // ^[ - Control Sequence Introducer (CSI)
-            result.key = String.fromCharCode(27);
-          } else if (ev.keyCode === 220) {
-            // ^\ - String Terminator (ST)
-            result.key = String.fromCharCode(28);
-          } else if (ev.keyCode === 221) {
-            // ^] - Operating System Command (OSC)
-            result.key = String.fromCharCode(29);
-          }
-        } else if ((!this.browser.isMac || this.options.macOptionIsMeta) && ev.altKey && !ev.metaKey) {
-          // On macOS this is a third level shift when !macOptionIsMeta. Use <Esc> instead.
-          const keyMapping = KEYCODE_KEY_MAPPINGS[ev.keyCode];
-          const key = keyMapping && keyMapping[!ev.shiftKey ? 0 : 1];
-          if (key) {
-            result.key = C0.ESC + key;
-          } else if (ev.keyCode >= 65 && ev.keyCode <= 90) {
-            const keyCode = ev.ctrlKey ? ev.keyCode - 64 : ev.keyCode + 32;
-            result.key = C0.ESC + String.fromCharCode(keyCode);
-          }
-        } else if (this.browser.isMac && !ev.altKey && !ev.ctrlKey && ev.metaKey) {
-          if (ev.keyCode === 65) { // cmd + a
-            this.selectAll();
-          }
-        }
-        break;
-    }
-
-    return result;
-  }
-
   /**
    * Set the G level of the terminal
    * @param g
diff --git a/src/core/Types.ts b/src/core/Types.ts
new file mode 100644
index 00000000..374b8f7d
--- /dev/null
+++ b/src/core/Types.ts
@@ -0,0 +1,10 @@
+/**
+ * Copyright (c) 2018 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+export interface IKeyboardResult {
+  cancel: boolean;
+  key: string;
+  scrollLines: number;
+}
diff --git a/src/core/input/Keyboard.ts b/src/core/input/Keyboard.ts
new file mode 100644
index 00000000..caaa9189
--- /dev/null
+++ b/src/core/input/Keyboard.ts
@@ -0,0 +1,353 @@
+/**
+ * Copyright (c) 2014 The xterm.js authors. All rights reserved.
+ * Copyright (c) 2012-2013, Christopher Jeffrey (MIT License)
+ * @license MIT
+ */
+
+import { IKeyboardEvent } from '../../base/Types';
+import { IKeyboardResult } from '../Types';
+import { C0 } from '../../EscapeSequences';
+
+// reg + shift key mappings for digits and special chars
+const KEYCODE_KEY_MAPPINGS: { [key: number]: [string, string]} = {
+  // digits 0-9
+  48: ['0', ')'],
+  49: ['1', '!'],
+  50: ['2', '@'],
+  51: ['3', '#'],
+  52: ['4', '$'],
+  53: ['5', '%'],
+  54: ['6', '^'],
+  55: ['7', '&'],
+  56: ['8', '*'],
+  57: ['9', '('],
+
+  // special chars
+  186: [';', ':'],
+  187: ['=', '+'],
+  188: [',', '<'],
+  189: ['-', '_'],
+  190: ['.', '>'],
+  191: ['/', '?'],
+  192: ['`', '~'],
+  219: ['[', '{'],
+  220: ['\\', '|'],
+  221: [']', '}'],
+  222: ['\'', '"']
+};
+
+export function evaluateKeyboardEvent(ev: IKeyboardEvent): IKeyboardResult {
+  const result: IKeyboardResult = {
+    // Whether to cancel event propogation (NOTE: this may not be needed since the event is
+    // canceled at the end of keyDown
+    cancel: false,
+    // The new key even to emit
+    key: undefined,
+    // The number of characters to scroll, if this is defined it will cancel the event
+    scrollLines: undefined
+  };
+  const modifiers = (ev.shiftKey ? 1 : 0) | (ev.altKey ? 2 : 0) | (ev.ctrlKey ? 4 : 0) | (ev.metaKey ? 8 : 0);
+  switch (ev.keyCode) {
+    case 0:
+      if (ev.key === 'UIKeyInputUpArrow') {
+        if (this.applicationCursor) {
+          result.key = C0.ESC + 'OA';
+        } else {
+          result.key = C0.ESC + '[A';
+        }
+      }
+      else if (ev.key === 'UIKeyInputLeftArrow') {
+        if (this.applicationCursor) {
+          result.key = C0.ESC + 'OD';
+        } else {
+          result.key = C0.ESC + '[D';
+        }
+      }
+      else if (ev.key === 'UIKeyInputRightArrow') {
+        if (this.applicationCursor) {
+          result.key = C0.ESC + 'OC';
+        } else {
+          result.key = C0.ESC + '[C';
+        }
+      }
+      else if (ev.key === 'UIKeyInputDownArrow') {
+        if (this.applicationCursor) {
+          result.key = C0.ESC + 'OB';
+        } else {
+          result.key = C0.ESC + '[B';
+        }
+      }
+      break;
+    case 8:
+      // backspace
+      if (ev.shiftKey) {
+        result.key = C0.BS; // ^H
+        break;
+      } else if (ev.altKey) {
+        result.key = C0.ESC + C0.DEL; // \e ^?
+        break;
+      }
+      result.key = C0.DEL; // ^?
+      break;
+    case 9:
+      // tab
+      if (ev.shiftKey) {
+        result.key = C0.ESC + '[Z';
+        break;
+      }
+      result.key = C0.HT;
+      result.cancel = true;
+      break;
+    case 13:
+      // return/enter
+      result.key = C0.CR;
+      result.cancel = true;
+      break;
+    case 27:
+      // escape
+      result.key = C0.ESC;
+      result.cancel = true;
+      break;
+    case 37:
+      // left-arrow
+      if (modifiers) {
+        result.key = C0.ESC + '[1;' + (modifiers + 1) + 'D';
+        // HACK: Make Alt + left-arrow behave like Ctrl + left-arrow: move one word backwards
+        // http://unix.stackexchange.com/a/108106
+        // macOS uses different escape sequences than linux
+        if (result.key === C0.ESC + '[1;3D') {
+          result.key = (this.browser.isMac) ? C0.ESC + 'b' : C0.ESC + '[1;5D';
+        }
+      } else if (this.applicationCursor) {
+        result.key = C0.ESC + 'OD';
+      } else {
+        result.key = C0.ESC + '[D';
+      }
+      break;
+    case 39:
+      // right-arrow
+      if (modifiers) {
+        result.key = C0.ESC + '[1;' + (modifiers + 1) + 'C';
+        // HACK: Make Alt + right-arrow behave like Ctrl + right-arrow: move one word forward
+        // http://unix.stackexchange.com/a/108106
+        // macOS uses different escape sequences than linux
+        if (result.key === C0.ESC + '[1;3C') {
+          result.key = (this.browser.isMac) ? C0.ESC + 'f' : C0.ESC + '[1;5C';
+        }
+      } else if (this.applicationCursor) {
+        result.key = C0.ESC + 'OC';
+      } else {
+        result.key = C0.ESC + '[C';
+      }
+      break;
+    case 38:
+      // up-arrow
+      if (modifiers) {
+        result.key = C0.ESC + '[1;' + (modifiers + 1) + 'A';
+        // HACK: Make Alt + up-arrow behave like Ctrl + up-arrow
+        // http://unix.stackexchange.com/a/108106
+        if (result.key === C0.ESC + '[1;3A') {
+          result.key = C0.ESC + '[1;5A';
+        }
+      } else if (this.applicationCursor) {
+        result.key = C0.ESC + 'OA';
+      } else {
+        result.key = C0.ESC + '[A';
+      }
+      break;
+    case 40:
+      // down-arrow
+      if (modifiers) {
+        result.key = C0.ESC + '[1;' + (modifiers + 1) + 'B';
+        // HACK: Make Alt + down-arrow behave like Ctrl + down-arrow
+        // http://unix.stackexchange.com/a/108106
+        if (result.key === C0.ESC + '[1;3B') {
+          result.key = C0.ESC + '[1;5B';
+        }
+      } else if (this.applicationCursor) {
+        result.key = C0.ESC + 'OB';
+      } else {
+        result.key = C0.ESC + '[B';
+      }
+      break;
+    case 45:
+      // insert
+      if (!ev.shiftKey && !ev.ctrlKey) {
+        // <Ctrl> or <Shift> + <Insert> are used to
+        // copy-paste on some systems.
+        result.key = C0.ESC + '[2~';
+      }
+      break;
+    case 46:
+      // delete
+      if (modifiers) {
+        result.key = C0.ESC + '[3;' + (modifiers + 1) + '~';
+      } else {
+        result.key = C0.ESC + '[3~';
+      }
+      break;
+    case 36:
+      // home
+      if (modifiers) {
+        result.key = C0.ESC + '[1;' + (modifiers + 1) + 'H';
+      } else if (this.applicationCursor) {
+        result.key = C0.ESC + 'OH';
+      } else {
+        result.key = C0.ESC + '[H';
+      }
+      break;
+    case 35:
+      // end
+      if (modifiers) {
+        result.key = C0.ESC + '[1;' + (modifiers + 1) + 'F';
+      } else if (this.applicationCursor) {
+        result.key = C0.ESC + 'OF';
+      } else {
+        result.key = C0.ESC + '[F';
+      }
+      break;
+    case 33:
+      // page up
+      if (ev.shiftKey) {
+        result.scrollLines = -(this.rows - 1);
+      } else {
+        result.key = C0.ESC + '[5~';
+      }
+      break;
+    case 34:
+      // page down
+      if (ev.shiftKey) {
+        result.scrollLines = this.rows - 1;
+      } else {
+        result.key = C0.ESC + '[6~';
+      }
+      break;
+    case 112:
+      // F1-F12
+      if (modifiers) {
+        result.key = C0.ESC + '[1;' + (modifiers + 1) + 'P';
+      } else {
+        result.key = C0.ESC + 'OP';
+      }
+      break;
+    case 113:
+      if (modifiers) {
+        result.key = C0.ESC + '[1;' + (modifiers + 1) + 'Q';
+      } else {
+        result.key = C0.ESC + 'OQ';
+      }
+      break;
+    case 114:
+      if (modifiers) {
+        result.key = C0.ESC + '[1;' + (modifiers + 1) + 'R';
+      } else {
+        result.key = C0.ESC + 'OR';
+      }
+      break;
+    case 115:
+      if (modifiers) {
+        result.key = C0.ESC + '[1;' + (modifiers + 1) + 'S';
+      } else {
+        result.key = C0.ESC + 'OS';
+      }
+      break;
+    case 116:
+      if (modifiers) {
+        result.key = C0.ESC + '[15;' + (modifiers + 1) + '~';
+      } else {
+        result.key = C0.ESC + '[15~';
+      }
+      break;
+    case 117:
+      if (modifiers) {
+        result.key = C0.ESC + '[17;' + (modifiers + 1) + '~';
+      } else {
+        result.key = C0.ESC + '[17~';
+      }
+      break;
+    case 118:
+      if (modifiers) {
+        result.key = C0.ESC + '[18;' + (modifiers + 1) + '~';
+      } else {
+        result.key = C0.ESC + '[18~';
+      }
+      break;
+    case 119:
+      if (modifiers) {
+        result.key = C0.ESC + '[19;' + (modifiers + 1) + '~';
+      } else {
+        result.key = C0.ESC + '[19~';
+      }
+      break;
+    case 120:
+      if (modifiers) {
+        result.key = C0.ESC + '[20;' + (modifiers + 1) + '~';
+      } else {
+        result.key = C0.ESC + '[20~';
+      }
+      break;
+    case 121:
+      if (modifiers) {
+        result.key = C0.ESC + '[21;' + (modifiers + 1) + '~';
+      } else {
+        result.key = C0.ESC + '[21~';
+      }
+      break;
+    case 122:
+      if (modifiers) {
+        result.key = C0.ESC + '[23;' + (modifiers + 1) + '~';
+      } else {
+        result.key = C0.ESC + '[23~';
+      }
+      break;
+    case 123:
+      if (modifiers) {
+        result.key = C0.ESC + '[24;' + (modifiers + 1) + '~';
+      } else {
+        result.key = C0.ESC + '[24~';
+      }
+      break;
+    default:
+      // a-z and space
+      if (ev.ctrlKey && !ev.shiftKey && !ev.altKey && !ev.metaKey) {
+        if (ev.keyCode >= 65 && ev.keyCode <= 90) {
+          result.key = String.fromCharCode(ev.keyCode - 64);
+        } else if (ev.keyCode === 32) {
+          // NUL
+          result.key = String.fromCharCode(0);
+        } else if (ev.keyCode >= 51 && ev.keyCode <= 55) {
+          // escape, file sep, group sep, record sep, unit sep
+          result.key = String.fromCharCode(ev.keyCode - 51 + 27);
+        } else if (ev.keyCode === 56) {
+          // delete
+          result.key = String.fromCharCode(127);
+        } else if (ev.keyCode === 219) {
+          // ^[ - Control Sequence Introducer (CSI)
+          result.key = String.fromCharCode(27);
+        } else if (ev.keyCode === 220) {
+          // ^\ - String Terminator (ST)
+          result.key = String.fromCharCode(28);
+        } else if (ev.keyCode === 221) {
+          // ^] - Operating System Command (OSC)
+          result.key = String.fromCharCode(29);
+        }
+      } else if ((!this.browser.isMac || this.options.macOptionIsMeta) && ev.altKey && !ev.metaKey) {
+        // On macOS this is a third level shift when !macOptionIsMeta. Use <Esc> instead.
+        const keyMapping = KEYCODE_KEY_MAPPINGS[ev.keyCode];
+        const key = keyMapping && keyMapping[!ev.shiftKey ? 0 : 1];
+        if (key) {
+          result.key = C0.ESC + key;
+        } else if (ev.keyCode >= 65 && ev.keyCode <= 90) {
+          const keyCode = ev.ctrlKey ? ev.keyCode - 64 : ev.keyCode + 32;
+          result.key = C0.ESC + String.fromCharCode(keyCode);
+        }
+      } else if (this.browser.isMac && !ev.altKey && !ev.ctrlKey && ev.metaKey) {
+        if (ev.keyCode === 65) { // cmd + a
+          this.selectAll();
+        }
+      }
+      break;
+  }
+
+  return result;
+}