    /*
    MIT License

    Copyright (c) 2019-2020 Andre Seidelt <superilu@yahoo.com>

    Permission is hereby granted, free of charge, to any person obtaining a copy
    of this software and associated documentation files (the "Software"), to deal
    in the Software without restriction, including without limitation the rights
    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    copies of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions:
    The above copyright notice and this permission notice shall be included in all
    copies or substantial portions of the Software.
    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    SOFTWARE.
    --------
    /**
    Additional code taken from MDN:
    https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String

    Code samples added on or after August 20, 2010 are in the public domain (CC0).
    No licensing notice is necessary, but if you need one, you can use:
    "Any copyright is dedicated to the Public Domain. http://creativecommons.org/publicdomain/zero/1.0/".
    */

    /** @module other */

    /**
     * @property {boolean} DEBUG enable/disable Debug() output.
     */
    DEBUG = false;

    /**
     * @property {boolean} REMOTE_DEBUG enable/disable Debug() sending via IPX.
     */
    REMOTE_DEBUG = false;

    /**
     * print javascript debug output if DEBUG is true.
     *
     * @param {string} str the message to print.
     */
    function Debug(str) {
    	_Debug(str);
    	if (REMOTE_DEBUG) {
    		IpxDebug(str + "\n");
    	}
    }

    /**
     * Internal debug which does not redirect to IPX if enabled.
     *
     * @param {string} str the message to print.
     */
    function _Debug(str) {
    	if (DEBUG) {
    		Println("-=> ", str);
    	}
    }

    /**
     * Print info message.
     *
     * @param {string} str the message to print.
     */
    function Info(str) {
    	Println(">>>", str);
    }

    /**
     * import a module.
     * @param {string} name module file name.
     * @returns the imported module.
     */
    function Require(name) {
    	// look in cache
    	if (name in Require._cache) {
    		Debug("Require(cached) " + name);
    		return Require._cache[name];
    	}

    	var names = [name, name + '.JS', 'JSBOOT/' + name, 'JSBOOT/' + name + '.JS'];
    	Debug("Require(names) " + JSON.stringify(names));

    	for (var i = 0; i < names.length; i++) {
    		var n = names[i];
    		Debug("Require() Trying '" + n + "'");
    		var content;
    		try {
    			content = Read(n);
    		} catch (e) {
    			Debug("Require() " + n + " Not found");
    			continue;
    		}
    		var exports = {};
    		Require._cache[name] = exports;
    		Function('exports', content)(exports);
    		return exports;
    	};

    	throw 'Could not load "' + name + '"';
    }
    Require._cache = Object.create(null);

    /**
     * include a module. The exported functions are copied into global scope.
     *
     * @param {string} name module file name.
     */
    function Include(name) {
    	var e = Require(name);
    	for (var key in e) {
    		Debug("Include(toGlobal) " + key);
    		global[key] = e[key];
    	}
    }

    /**
     * add toString() to Error class.
     */
    Error.prototype.toString = function () {
    	if (this.stackTrace) { return this.name + ': ' + this.message + this.stackTrace; }
    	return this.name + ': ' + this.message;
    };

    /**
     * print startup info with screen details.
     */
    function StartupInfo() {
    	var mode = GetScreenMode();
    	var width = SizeX();
    	var height = SizeY();

    	Info("Screen size: " + width + "x" + height + "x" + mode);
    	Info("Memory: " + JSON.stringify(MemoryInfo()));
    	Info("Command line args: " + JSON.stringify(ARGS));
    	Info("SerialPorts: " + JSON.stringify(GetSerialPorts().map(function (e) { return "0x" + e.toString(16) })));
    	Info("ParallelPorts: " + JSON.stringify(GetParallelPorts().map(function (e) { return "0x" + e.toString(16) })));

    	if (DEBUG) {
    		var funcs = [];
    		var other = [];
    		for (var e in global) {
    			if (typeof global[e] === "function") {
    				funcs.push(e + "()");
    			} else {
    				other.push(e);
    			}
    		}
    		funcs.sort();
    		other.sort();
    		_Debug("Known globals:");
    		for (var i = 0; i < other.length; i++) {
    			_Debug("    " + other[i]);
    		}
    		_Debug("Known functions:");
    		for (var i = 0; i < funcs.length; i++) {
    			_Debug("    " + funcs[i]);
    		}
    	}
    }
    StartupInfo();

    /**
     * get char code.
     *
     * @param {string} s a string
     * @returns the ASCII-code of the first character.
     */
    function CharCode(s) {
    	return s.charCodeAt(0);
    }

    /**
     * compare a keycode with a character.
     *
     * @param {number} k keycode from an Event
     * @param {string} s a string with one char
     */
    function CompareKey(k, s) {
    	return (k & 0xFF) == CharCode(s);
    }

    /**
     * get random integer between min and max (or between 0 and min if max is not provided).
     *
     * @param {number} min min
     * @param {number} max max
     *
     * @returns {number} an integer between min and max.
     */
    function RandomInt(min, max) {
    	if (max === undefined) {
    		max = min;
    		min = 0;
    	}

    	return Math.floor(Math.random() * (max - min) + min);
    }

    // add startsWith() endsWith() to String class
    if (!String.prototype.startsWith) {
    	Object.defineProperty(String.prototype, 'startsWith', {
    		value: function (search, rawPos) {
    			var pos = rawPos > 0 ? rawPos | 0 : 0;
    			return this.substring(pos, pos + search.length) === search;
    		}
    	});
    }
    if (!String.prototype.endsWith) {
    	String.prototype.endsWith = function (search, this_len) {
    		if (this_len === undefined || this_len > this.length) {
    			this_len = this.length;
    		}
    		return this.substring(this_len - search.length, this_len) === search;
    	};
    }

    /**
     * Write the given value to io-port 80h to be displayed by a POST card.
     *
     * @param {number} val value to write to 0x80.
     */
    function POST(val) {
    	OutPortByte(0x80, val);
    }

    /*
    see:
    https://en.wikipedia.org/wiki/Parallel_port
    http://electrosofts.com/parallel/
    https://web.archive.org/web/20120301022928/http://retired.beyondlogic.org/spp/parallel.pdf
    https://stanislavs.org/helppc/bios_data_area.html
    */

    var _lptPorts = GetParallelPorts();

    /**
     * read/write data to LPT data register.
     *
     * @param {number} port port number (0-3).
     * @param {number} data data to write, null to read
     *
     * @returns {number} current LPT value if data was null.
     *
     * @see GetParallelPorts
     */
    function LPTRawData(port, data) {
    	if (port < 0 && ports >= _lptPorts.length) {
    		throw 'LPT port out of range';
    	}
    	var addr = _lptPorts[port];

    	var old = InPortByte(addr + PARALLEL.CONTROL.ADDR);
    	if (data) {
    		OutPortByte(addr + PARALLEL.CONTROL.ADDR, old & ~PARALLEL.CONTROL.BIDI);

    		OutPortByte(addr + PARALLEL.DATA.ADDR, data);
    	} else {
    		OutPortByte(addr + PARALLEL.CONTROL.ADDR, old | PARALLEL.CONTROL.BIDI);

    		return InPortByte(addr + PARALLEL.DATA.ADDR);
    	}
    }

    /**
     * read status register of LPT port.
     *
     * @param {number} port port number (0-3).
     *
     * @see GetParallelPorts
     */
    function LPTRawStatus(port) {
    	if (port < 0 && ports >= _lptPorts.length) {
    		throw 'LPT port out of range';
    	}
    	var addr = _lptPorts[port];

    	return InPortByte(addr + PARALLEL.STATUS.ADDR);
    }

    /**
     * write bits to LPT control register.
     *
     * @param {number} port port number (0-3).
     * @param {number} bits data to write
     *
     * @see GetParallelPorts
     */
    function LPTRawControl(port, bits) {
    	if (port < 0 && ports >= _lptPorts.length) {
    		throw 'LPT port out of range';
    	}
    	var addr = _lptPorts[port];

    	OutPortByte(addr + PARALLEL.CONTROL.ADDR, bits);
    }

    /**
     * reset parallel port.
     * @param {number} port port number (0-3).
     *
     * @see GetParallelPorts
     */
    function LPTReset(port) {
    	if (port < 0 && ports >= _lptPorts.length) {
    		throw 'LPT port out of range';
    	}
    	_LPTReset(port);
    }

    /**
     * send data to parallel port.
     * @param {number} port port number (0-3).
     * @param {string} data data to transfer.
     *
     * @see GetParallelPorts
     */
    function LPTSend(port, data) {
    	if (port < 0 && ports >= _lptPorts.length) {
    		throw 'LPT port out of range';
    	}
    	_LPTSend(port, data);
    }

    /**
     * read parallel port status.
     * @param {number} port port number (0-3).
     *
     * @see GetParallelPorts
     */
    function LPTStatus(port) {
    	if (port < 0 && ports >= _lptPorts.length) {
    		throw 'LPT port out of range';
    	}
    	return _LPTStatus(port);
    }

    /**
     * parallel port IO register definitions.
     *
     *  [*] CONTROL.BIDI must be set to 1 in order to read from DATA. Not supported by all ports!
     *
     * @property {*} DATA.BIT0 Data 0, pin 2 (out/in*)
     * @property {*} DATA.BIT1 Data 1, pin 3 (out/in*)
     * @property {*} DATA.BIT2 Data 2, pin 4 (out/in*)
     * @property {*} DATA.BIT3 Data 3, pin 5 (out/in*)
     * @property {*} DATA.BIT4 Data 4, pin 6 (out/in*)
     * @property {*} DATA.BIT5 Data 5, pin 7 (out/in*)
     * @property {*} DATA.BIT6 Data 6, pin 8 (out/in*)
     * @property {*} DATA.BIT7 Data 7, pin 9 (out/in*)
     *
     * @property {*} STATUS.BUSY pin 11, inverted (in)
     * @property {*} STATUS.ACK pin 10 (in)
     * @property {*} STATUS.PAPER_OUT pin 12 (in)
     * @property {*} STATUS.SELECT_IN pin 13 (in)
     * @property {*} STATUS.ERROR pin 15 (in)
     * @property {*} STATUS.TIMEOUT LPTStatus() only
     *
     * @property {*} CONTROL.BIDI this bit must be set in order to read DATA
     * @property {*} CONTROL.SELECT_OUT pin 17, inverted (out)
     * @property {*} CONTROL.RESET pin 16 (out)
     * @property {*} CONTROL.LINEFEED pin 14, inverted (out)
     * @property {*} CONTROL.STROBE pin 1, inverted (out)
     */
    PARALLEL = {
    	DATA: {
    		ADDR: 0,
    		BIT0: (1 << 0),
    		BIT1: (1 << 1),
    		BIT2: (1 << 2),
    		BIT3: (1 << 3),
    		BIT4: (1 << 4),
    		BIT5: (1 << 5),
    		BIT6: (1 << 6),
    		BIT7: (1 << 7)
    	},
    	STATUS: {
    		ADDR: 1,
    		BUSY: (1 << 7),
    		ACK: (1 << 6),
    		PAPER_OUT: (1 << 5),
    		SELECT_IN: (1 << 4),
    		ERROR: (1 << 3),
    		TIMEOUT: (1 << 1)
    	},
    	CONTROL: {
    		ADDR: 2,
    		BIDI: (1 << 5),
    		SELECT_OUT: (1 << 3),
    		RESET: (1 << 2),
    		LINEFEED: (1 << 1),
    		STROBE: (1 << 0)
    	}
    };

    /**
     * sound input selection.
     * @property {*} Input.MIC use microphone input
     * @property {*} Input.LINE use line input
     * @property {*} Input.CD use CD input
     * @property {*} Bits.BITS8 use 8 bits
     * @property {*} Bits.BITS16 use 16 bits
     */
    SOUND = {
    	Input: {
    		MIC: 1,
    		LINE: 2,
    		CD: 3
    	},
    	Bits: {
    		BITS8: 8,
    		BITS16: 16
    	}
    };

    /**
     * System() flags for subsystem shutdown/restart.
     * @property {*} MOUSE de/reinit mouse
     * @property {*} SOUND de/reinit sound
     * @property {*} JOYSTICK de/reinit joystick
     * @property {*} KEYBOARD de/reinit keyboard
     * @property {*} TIMER de/reinit timer
     */
    SYSTEM = {
    	MOUSE: 0x01,
    	SOUND: 0x02,
    	JOYSTICK: 0x04,
    	KEYBOARD: 0x08,
    	TIMER: 0x10
    };

    /**
     * event interface.
     * @property {*} Mode.NONE no cursor
     * @property {*} Mode.ARROW arrow cursor
     * @property {*} Mode.BUSY busy cursor
     * @property {*} Mode.QUESTION questionmark cursor
     * @property {*} Mode.CURSOR_EDIT edit cursor
     * @property {*} Buttons mouse button definitions
     * @property {*} Buttons.LEFT
     * @property {*} Buttons.RIGHT
     * @property {*} Buttons.MIDDLE
     */
    MOUSE = {
    	Mode: {
    		NONE: 0,
    		ARROW: 2,
    		BUSY: 3,
    		QUESTION: 4,
    		CURSOR_EDIT: 5
    	},
    	Buttons: {
    		LEFT: 0x01,
    		RIGHT: 0x02,
    		MIDDLE: 0x04
    	}
    };

    /**
     * keyboard input.
     * @property {*} Code key definitions.
     */
    KEY = {
    	Code: {
    		NoKey: -1,		/* no key available */
    		/* Letters and numbers are missing from the definitions but can be obtained by e.g. CharCode('A'). */

    		KEY_A: 1,
    		KEY_B: 2,
    		KEY_C: 3,
    		KEY_D: 4,
    		KEY_E: 5,
    		KEY_F: 6,
    		KEY_G: 7,
    		KEY_H: 8,
    		KEY_I: 9,
    		KEY_J: 10,
    		KEY_K: 11,
    		KEY_L: 12,
    		KEY_M: 13,
    		KEY_N: 14,
    		KEY_O: 15,
    		KEY_P: 16,
    		KEY_Q: 17,
    		KEY_R: 18,
    		KEY_S: 19,
    		KEY_T: 20,
    		KEY_U: 21,
    		KEY_V: 22,
    		KEY_W: 23,
    		KEY_X: 24,
    		KEY_Y: 25,
    		KEY_Z: 26,
    		KEY_0: 27,
    		KEY_1: 28,
    		KEY_2: 29,
    		KEY_3: 30,
    		KEY_4: 31,
    		KEY_5: 32,
    		KEY_6: 33,
    		KEY_7: 34,
    		KEY_8: 35,
    		KEY_9: 36,
    		KEY_0_PAD: 37,
    		KEY_1_PAD: 38,
    		KEY_2_PAD: 39,
    		KEY_3_PAD: 40,
    		KEY_4_PAD: 41,
    		KEY_5_PAD: 42,
    		KEY_6_PAD: 43,
    		KEY_7_PAD: 44,
    		KEY_8_PAD: 45,
    		KEY_9_PAD: 46,
    		KEY_F1: 47,
    		KEY_F2: 48,
    		KEY_F3: 49,
    		KEY_F4: 50,
    		KEY_F5: 51,
    		KEY_F6: 52,
    		KEY_F7: 53,
    		KEY_F8: 54,
    		KEY_F9: 55,
    		KEY_F10: 56,
    		KEY_F11: 57,
    		KEY_F12: 58,
    		KEY_ESC: 59,
    		KEY_TILDE: 60,
    		KEY_MINUS: 61,
    		KEY_EQUALS: 62,
    		KEY_BACKSPACE: 63,
    		KEY_TAB: 64,
    		KEY_OPENBRACE: 65,
    		KEY_CLOSEBRACE: 66,
    		KEY_ENTER: 67,
    		KEY_COLON: 68,
    		KEY_QUOTE: 69,
    		KEY_BACKSLASH: 70,
    		KEY_BACKSLASH2: 71,
    		KEY_COMMA: 72,
    		KEY_STOP: 73,
    		KEY_SLASH: 74,
    		KEY_SPACE: 75,
    		KEY_INSERT: 76,
    		KEY_DEL: 77,
    		KEY_HOME: 78,
    		KEY_END: 79,
    		KEY_PGUP: 80,
    		KEY_PGDN: 81,
    		KEY_LEFT: 82,
    		KEY_RIGHT: 83,
    		KEY_UP: 84,
    		KEY_DOWN: 85,
    		KEY_SLASH_PAD: 86,
    		KEY_ASTERISK: 87,
    		KEY_MINUS_PAD: 88,
    		KEY_PLUS_PAD: 89,
    		KEY_DEL_PAD: 90,
    		KEY_ENTER_PAD: 91,
    		KEY_PRTSCR: 92,
    		KEY_PAUSE: 93,
    		KEY_ABNT_C1: 94,
    		KEY_YEN: 95,
    		KEY_KANA: 96,
    		KEY_CONVERT: 97,
    		KEY_NOCONVERT: 98,
    		KEY_AT: 99,
    		KEY_CIRCUMFLEX: 100,
    		KEY_COLON2: 101,
    		KEY_KANJI: 102,
    		KEY_EQUALS_PAD: 103,  /* MacOS X */
    		KEY_BACKQUOTE: 104,  /* MacOS X */
    		KEY_SEMICOLON: 105,  /* MacOS X */
    		KEY_COMMAND: 106,  /* MacOS X */
    		KEY_UNKNOWN1: 107,
    		KEY_UNKNOWN2: 108,
    		KEY_UNKNOWN3: 109,
    		KEY_UNKNOWN4: 110,
    		KEY_UNKNOWN5: 111,
    		KEY_UNKNOWN6: 112,
    		KEY_UNKNOWN7: 113,
    		KEY_UNKNOWN8: 114,

    		KEY_MODIFIERS: 115,

    		KEY_LSHIFT: 115,
    		KEY_RSHIFT: 116,
    		KEY_LCONTROL: 117,
    		KEY_RCONTROL: 118,
    		KEY_ALT: 119,
    		KEY_ALTGR: 120,
    		KEY_LWIN: 121,
    		KEY_RWIN: 122,
    		KEY_MENU: 123,
    		KEY_SCRLOCK: 124,
    		KEY_NUMLOCK: 125,
    		KEY_CAPSLOCK: 126
    	}
    };