diff --git a/src/core/config/Categories.json b/src/core/config/Categories.json
index 3e0d108e..f3b73921 100755
--- a/src/core/config/Categories.json
+++ b/src/core/config/Categories.json
@@ -103,7 +103,8 @@
             "Citrix CTX1 Encode",
             "Citrix CTX1 Decode",
             "Pseudo-Random Number Generator",
-            "Enigma"
+            "Enigma",
+            "Typex"
         ]
     },
     {
diff --git a/src/core/operations/Typex.mjs b/src/core/operations/Typex.mjs
new file mode 100644
index 00000000..89114863
--- /dev/null
+++ b/src/core/operations/Typex.mjs
@@ -0,0 +1,396 @@
+/**
+ * Emulation of the Typex machine.
+ *
+ * @author s2224834
+ * @copyright Crown Copyright 2019
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import OperationError from "../errors/OperationError";
+import Utils from "../Utils";
+import * as Enigma from "../lib/Enigma";
+
+const ROTORS = [
+    {name: "1", value: "QWECYJIBFKMLTVZPOHUDGNRSXA<ACEINQTVY"},
+    {name: "2", value: "AJDKSIRUXBLHWTMCQGZNPYFVOE<ACEINQTVY"},
+    {name: "3", value: "BDFHJLCPRTXVZNYEIWGAKMUSQO<ACEINQTVY"},
+    {name: "4", value: "ESOVPZJAYQUIRHXLNFTGKDCMWB<ACEINQTVY"},
+    {name: "5", value: "VZBRGITYUPSDNHLXAWMJQOFECK<ACEINQTVY"},
+    {name: "6", value: "FVPJIAOYEDRZXWGCTKUQSBNMHL<ACEINQTVY"},
+    {name: "7", value: "KZGLIUCJEHADXRYWVTNSFQPMOB<ACEINQTVY"},
+    {name: "8", value: "ZLVGOIFTYWUEPMABNCXRQSDKHJ<ACEINQTVY"},
+];
+
+const REFLECTORS = [
+    {name: "Standard", value: "MO VW GL JX TZ AY EQ IP KN DH CU FS BR"},
+];
+
+// Special character handling on Typex keyboard
+const KEYBOARD = {
+    "Q": "1", "W": "2", "E": "3", "R": "4", "T": "5", "Y": "6", "U": "7", "I": "8", "O": "9", "P": "0",
+    "A": "-", "S": "/", "D": "Z", "F": "%", "G": "X", "H": "£", "K": "(", "L": ")",
+    "C": "V", "B": "'", "N": ",", "M": "."
+};
+const KEYBOARD_REV = {};
+for (const i of Object.keys(KEYBOARD)) {
+    KEYBOARD_REV[KEYBOARD[i]] = i;
+}
+
+/**
+ * Typex machine. A lot like the Enigma, but five rotors, of which the first two are static.
+ */
+class TypexMachine extends Enigma.EnigmaBase {
+    /**
+     * TypexMachine constructor.
+     *
+     * @param {Object[]} rotors - List of Rotors.
+     * @param {Object} reflector - A Reflector.
+     * @param {Plugboard} plugboard - A Plugboard.
+     */
+    constructor(rotors, reflector, plugboard, keyboard) {
+        super(rotors, reflector, plugboard);
+        if (rotors.length !== 5) {
+            throw new OperationError("Typex must have 5 rotors");
+        }
+        this.keyboard = keyboard;
+    }
+
+    /**
+     * This is the same as the Enigma step function, it's just that the right-
+     * most two rotors are static.
+     */
+    step() {
+        const r0 = this.rotors[2];
+        const r1 = this.rotors[3];
+        r0.step();
+        // The second test here is the double-stepping anomaly
+        if (r0.steps.has(r0.pos) || r1.steps.has(Utils.mod(r1.pos + 1, 26))) {
+            r1.step();
+            if (r1.steps.has(r1.pos)) {
+                const r2 = this.rotors[4];
+                r2.step();
+            }
+        }
+    }
+
+    /**
+     * Encrypt/decrypt data. This is identical to the Enigma version cryptographically, but we have
+     * additional handling for the Typex's keyboard (which handles various special characters by
+     * mapping them to particular letter combinations).
+     *
+     * @param {string} input - The data to encrypt/decrypt.
+     * @return {string}
+     */
+    crypt(input) {
+        let inputMod = input;
+        if (this.keyboard === "Encrypt") {
+            inputMod = "";
+            // true = in symbol mode
+            let mode = false;
+            for (const x of input) {
+                if (x === " ") {
+                    inputMod += "X";
+                } else if (mode) {
+                    if (KEYBOARD_REV.hasOwnProperty(x)) {
+                        inputMod += KEYBOARD_REV[x];
+                    } else {
+                        mode = false;
+                        inputMod += "V" + x;
+                    }
+                } else {
+                    if (KEYBOARD_REV.hasOwnProperty(x)) {
+                        mode = true;
+                        inputMod += "Z" + KEYBOARD_REV[x];
+                    } else {
+                        inputMod += x;
+                    }
+                }
+            }
+        }
+
+        const output = super.crypt(inputMod);
+
+        let outputMod = output;
+        if (this.keyboard === "Decrypt") {
+            outputMod = "";
+            let mode = false;
+            for (const x of output) {
+                if (x === "X") {
+                    outputMod += " ";
+                } else if (x === "V") {
+                    mode = false;
+                } else if (x === "Z") {
+                    mode = true;
+                } else if (mode) {
+                    outputMod += KEYBOARD[x];
+                } else {
+                    outputMod += x;
+                }
+            }
+        }
+        return outputMod;
+    }
+}
+
+/**
+ * Typex rotor. Like an Enigma rotor, but no ring setting, and can be reversed.
+ */
+class Rotor extends Enigma.Rotor {
+    /**
+     * Rotor constructor.
+     *
+     * @param {string} wiring - A 26 character string of the wiring order.
+     * @param {string} steps - A 0..26 character string of stepping points.
+     * @param {bool} reversed - Whether to reverse the rotor.
+     * @param {char} initialPosition - The initial position of the rotor.
+     */
+    constructor(wiring, steps, reversed, initialPos) {
+        let initialPosMod = initialPos;
+        let wiringMod = wiring;
+        if (reversed) {
+            initialPosMod = Enigma.i2a(Utils.mod(26 - Enigma.a2i(initialPos), 26));
+            const outMap = new Array(26).fill();
+            for (let i=0; i<26; i++) {
+                // wiring[i] is the original output
+                // Enigma.LETTERS[i] is the original input
+                const input = Utils.mod(26 - Enigma.a2i(wiring[i]), 26);
+                const output = Enigma.i2a(Utils.mod(26 - Enigma.a2i(Enigma.LETTERS[i]), 26));
+                outMap[input] = output;
+            }
+            wiringMod = outMap.join("");
+        }
+        super(wiringMod, steps, "A", initialPosMod);
+    }
+}
+
+/**
+ * Typex input plugboard. Based on a Rotor, because it allows arbitrary maps, not just switches
+ * like the Enigma plugboard.
+ * Not to be confused with the reflector plugboard.
+ */
+class Plugboard extends Enigma.Rotor {
+    /**
+     * Typex plugboard constructor.
+     *
+     * @param {string} wiring - 26 character string of mappings from A-Z, as per rotors, or "".
+     */
+    constructor(wiring) {
+        try {
+            super(wiring, "", "A", "A");
+        } catch (err) {
+            throw new OperationError(err.message.replace("Rotor", "Plugboard"));
+        }
+    }
+}
+
+/**
+ * Typex operation
+ */
+class TypexOp extends Operation {
+    /**
+     * Typex constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Typex";
+        this.module = "Default";
+        this.description = "Encipher/decipher with the WW2 Typex machine.<br><br>The standard set of rotors are provided. Later Typexes had a plugboard to configure the reflector: to configure this, enter a string of connected pairs of letters, e.g. <code>AB CD EF</code> connects A to B, C to D, and E to F (you'll need to connect every letter). These Typexes also have an input plugboard: unlike Enigma's plugboard, it's not restricted to pairs, so it's entered like a rotor. To create your own rotor, enter the letters that the rotor maps A to Z to, in order, optionally followed by <code>&lt;</code> then a list of stepping points.";
+        this.infoURL = "https://wikipedia.org/wiki/Typex";
+        this.inputType = "string";
+        this.outputType = "string";
+        this.args = [
+            {
+                name: "1st (right-hand, static) rotor",
+                type: "editableOption",
+                value: ROTORS,
+                defaultIndex: 4
+            },
+            {
+                name: "1st rotor reversed",
+                type: "boolean",
+                value: false
+            },
+            {
+                name: "1st rotor initial value",
+                type: "option",
+                value: Enigma.LETTERS
+            },
+            {
+                name: "2nd (static) rotor",
+                type: "editableOption",
+                value: ROTORS,
+                defaultIndex: 3
+            },
+            {
+                name: "2nd rotor reversed",
+                type: "boolean",
+                value: false
+            },
+            {
+                name: "2nd rotor initial value",
+                type: "option",
+                value: Enigma.LETTERS
+            },
+            {
+                name: "3rd rotor",
+                type: "editableOption",
+                value: ROTORS,
+                defaultIndex: 2
+            },
+            {
+                name: "3rd rotor reversed",
+                type: "boolean",
+                value: false
+            },
+            {
+                name: "3rd rotor initial value",
+                type: "option",
+                value: Enigma.LETTERS
+            },
+            {
+                name: "4th rotor",
+                type: "editableOption",
+                value: ROTORS,
+                defaultIndex: 1
+            },
+            {
+                name: "4th rotor reversed",
+                type: "boolean",
+                value: false
+            },
+            {
+                name: "4th rotor initial value",
+                type: "option",
+                value: Enigma.LETTERS
+            },
+            {
+                name: "5th rotor",
+                type: "editableOption",
+                value: ROTORS,
+                defaultIndex: 0
+            },
+            {
+                name: "5th rotor reversed",
+                type: "boolean",
+                value: false
+            },
+            {
+                name: "5th rotor initial value",
+                type: "option",
+                value: Enigma.LETTERS
+            },
+            {
+                name: "Reflector",
+                type: "editableOption",
+                value: REFLECTORS
+            },
+            {
+                name: "Plugboard",
+                type: "string",
+                value: ""
+            },
+            {
+                name: "Typex keyboard emulation",
+                type: "option",
+                value: ["None", "Encrypt", "Decrypt"]
+            },
+            {
+                name: "Strict output",
+                hint: "Remove non-alphabet letters and group output",
+                type: "boolean",
+                value: true
+            },
+        ];
+    }
+
+    /**
+     * Helper - for ease of use rotors are specified as a single string; this
+     * method breaks the spec string into wiring and steps parts.
+     *
+     * @param {string} rotor - Rotor specification string.
+     * @param {number} i - For error messages, the number of this rotor.
+     * @returns {string[]}
+     */
+    parseRotorStr(rotor, i) {
+        if (rotor === "") {
+            throw new OperationError(`Rotor ${i} must be provided.`);
+        }
+        if (!rotor.includes("<")) {
+            return [rotor, ""];
+        }
+        return rotor.split("<", 2);
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run(input, args) {
+        const reflectorstr = args[15];
+        const plugboardstr = args[16];
+        const typexKeyboard = args[17];
+        const removeOther = args[18];
+        const rotors = [];
+        for (let i=0; i<5; i++) {
+            const [rotorwiring, rotorsteps] = this.parseRotorStr(args[i*3]);
+            rotors.push(new Rotor(rotorwiring, rotorsteps, args[i*3 + 1], args[i*3+2]));
+        }
+        const reflector = new Enigma.Reflector(reflectorstr);
+        let plugboardstrMod = plugboardstr;
+        if (plugboardstrMod === "") {
+            plugboardstrMod = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+        }
+        const plugboard = new Plugboard(plugboardstrMod);
+        if (removeOther) {
+            if (typexKeyboard === "Encrypt") {
+                input = input.replace(/[^A-Za-z0-9 /%£()',.-]/g, "");
+            } else {
+                input = input.replace(/[^A-Za-z]/g, "");
+            }
+        }
+        const typex = new TypexMachine(rotors, reflector, plugboard, typexKeyboard);
+        let result = typex.crypt(input);
+        if (removeOther && typexKeyboard !== "Decrypt") {
+            // Five character cipher groups is traditional
+            result = result.replace(/([A-Z]{5})(?!$)/g, "$1 ");
+        }
+        return result;
+    }
+
+    /**
+     * Highlight Typex
+     * This is only possible if we're passing through non-alphabet characters.
+     *
+     * @param {Object[]} pos
+     * @param {number} pos[].start
+     * @param {number} pos[].end
+     * @param {Object[]} args
+     * @returns {Object[]} pos
+     */
+    highlight(pos, args) {
+        if (args[18] === false) {
+            return pos;
+        }
+    }
+
+    /**
+     * Highlight Typex in reverse
+     *
+     * @param {Object[]} pos
+     * @param {number} pos[].start
+     * @param {number} pos[].end
+     * @param {Object[]} args
+     * @returns {Object[]} pos
+     */
+    highlightReverse(pos, args) {
+        if (args[18] === false) {
+            return pos;
+        }
+    }
+
+}
+
+export default TypexOp;