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510 lines
14 KiB
JavaScript
510 lines
14 KiB
JavaScript
//
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// Applesoft BASIC in Javascript
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// DOS Emulation
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// Copyright (C) 2009-2011 Joshua Bell
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// Usage:
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// var dos = new DOS( tty ) // hooks tty's writeChar/readChar/readLine
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// dos.reset() // Close all open buffers
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/*global basic*/
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function DOS(tty) {
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/*jslint bitwise: false, browser: true*/
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var DOSErrors = {
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LANGUAGE_NOT_AVAILABLE: [1, "Language not available"],
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RANGE_ERROR: [2, 'Range error'],
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WRITE_PROTECTED: [4, 'Write protected'],
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END_OF_DATA: [5, 'End of data'],
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FILE_NOT_FOUND: [6, 'File not found'],
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VOLUME_MISMATCH: [7, 'Volume mismatch'],
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IO_ERROR: [8, 'I/O error'],
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DISK_FULL: [9, 'Disk full'],
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FILE_LOCKED: [10, 'File locked'],
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INVALID_OPTION: [11, 'Invalid option'],
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NO_BUFFERS_AVAILABLE: [12, 'No buffers available'],
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FILE_TYPE_MISMATCH: [13, 'File type mismatch'],
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PROGRAM_TOO_LARGE: [14, 'Program too large'],
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NOT_DIRECT_COMMAND: [15, 'Not direct command']
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},
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STORAGE_PREFIX = 'vfs/',
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// For MON/NOMON
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MON_I = 1,
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MON_C = 2,
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MON_O = 4,
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// Original versions of hooked I/O routines
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tty_readLine,
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tty_readChar,
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tty_writeChar,
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// character output state
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commandBuffer = "",
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commandMode = false,
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// I/O buffers
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buffers = {},
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activebuffer = null,
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mode = "",
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// other state
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monico = 0;
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function doserror(msg) {
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throw new basic.RuntimeError(msg[1], msg[0]);
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}
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// Internal - crack arguments e.g. ",S6,D1"
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function parseArgs(str, opts) {
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opts = opts || '';
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// Set these to zero so they're always defined when passed into command handlers
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var args = {
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V: 0, // Volume
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D: 0, // Drive
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S: 0, // Slot
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L: 0, // Length
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R: 0, // Record/Relative
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B: 0, // Byte
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A: 0, // Address
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C: undefined, // Echo Commands
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I: undefined, // Echo Input
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O: undefined // Echo Output
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};
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while (str.match(/^,?\s*([VDSLRBACIO])\s*([0-9]+|\$[0-9A-Fa-f]+)?\s*([\x20-\x7E]*)/)) {
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if (opts.indexOf(RegExp.$1) === -1) {
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doserror(DOSErrors.INVALID_OPTION);
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}
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args[RegExp.$1] = Number(RegExp.$2);
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str = RegExp.$3;
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}
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if (str.length > 0) {
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doserror(DOSErrors.INVALID_OPTION);
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}
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return args;
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}
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//----------------------------------------------------------------------
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// Browser-side VFS
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//----------------------------------------------------------------------
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function vfs_set(key, value) {
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return window.localStorage.setItem(STORAGE_PREFIX + key, encodeURIComponent(value));
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}
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function vfs_get(key) {
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var item = window.localStorage.getItem(STORAGE_PREFIX + key);
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return item !== null ? decodeURIComponent(item) : null;
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}
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function vfs_remove(key) {
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return window.localStorage.removeItem(STORAGE_PREFIX + key);
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}
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//----------------------------------------------------------------------
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// Implementation
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//----------------------------------------------------------------------
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this.reset = function _reset() {
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buffers = {};
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activebuffer = null;
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mode = "";
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};
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function unlink(filename) {
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var item = vfs_get(filename);
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if (item === null) {
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doserror(DOSErrors.FILE_NOT_FOUND);
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}
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vfs_remove(filename);
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}
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function rename(oldname, newname) {
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var item = vfs_get(oldname);
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if (item === null) {
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doserror(DOSErrors.FILE_NOT_FOUND);
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}
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vfs_remove(oldname);
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vfs_set(newname, item);
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}
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function open(filename, recordlength) {
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if (recordlength === 0) {
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// Sequential access
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recordlength = 1;
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}
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// Peek in the VFS cache first
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var file = vfs_get(filename),
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req, url, async;
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if (file === null) {
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// Not cached - do a synchronous XmlHttpRequest for the file here
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req = new XMLHttpRequest();
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try {
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url = "vfs/" + encodeURIComponent(filename.replace(/\./g, '_')) + ".txt";
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async = false;
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req.open("GET", url, async);
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req.send(null);
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if (req.status === 200 || req.status === 0) { // 0 for file:// protocol
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file = req.responseText.replace(/\r\n/g, "\r");
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vfs_set(filename, file);
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}
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} catch (e) {
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// File doesn't exist - APPEND/READ will fail
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throw e;
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}
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}
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// Create a buffer for the file
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buffers[filename] = {
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file: file,
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recordlength: recordlength,
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recordnum: 0,
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filepointer: 0
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};
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}
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function append(filename, recordlength) {
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// Normal open logic
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open(filename, recordlength);
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if (!buffers.hasOwnProperty(filename)) {
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doserror(DOSErrors.FILE_NOT_FOUND);
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}
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var buf = buffers[filename];
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// Then seek to the end of the file
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buf.filepointer = buf.file.length;
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buf.recordnum = Math.floor(buf.filepointer / buf.recordlength);
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}
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function close(filename) {
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var buf, fn;
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// If not specified, close all buffers
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if (!filename) {
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for (fn in buffers) {
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if (buffers.hasOwnProperty(fn)) {
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close(fn);
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}
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}
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return;
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}
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buf = buffers[filename];
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if (buf) {
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// flush changes to "disk"
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vfs_set(filename, buf.file);
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delete buffers[filename];
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if (buf === activebuffer) {
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activebuffer = null;
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mode = "";
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}
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}
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}
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function read(filename, recordnum, bytenum) {
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var buf = buffers[filename];
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if (!buf) {
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// Open file if no such named buffer, but don't create it
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open(filename, 0);
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buf = buffers[filename];
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}
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if (buf.file === null) {
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doserror(DOSErrors.FILE_NOT_FOUND);
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}
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// Set the file position
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buf.recordnum = recordnum;
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buf.filepointer = buf.recordlength * recordnum + bytenum;
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// Set the active buffer into read mode
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activebuffer = buf;
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mode = "r";
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}
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function write(filename, recordnum, bytenum) {
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var buf = buffers[filename];
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if (!buf) {
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// Must open the file before writing
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doserror(DOSErrors.FILE_NOT_FOUND);
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}
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if (buf.file === null) {
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// If we still don't have it, create in VFS if necessary
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vfs_set(filename, '');
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buf.file = '';
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}
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// Set up the file position
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buf.recordnum = recordnum;
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if (buf.recordlength > 1) {
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buf.filepointer = buf.recordlength * recordnum;
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}
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buf.filepointer += bytenum;
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// Set the active buffer into write mode
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activebuffer = buf;
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mode = "w";
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}
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function position(filename, records) {
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var buf = buffers[filename];
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if (!buf) {
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// Open file if no such named buffer, but don't create it
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open(filename, 0, false);
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buf = buffers[filename];
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}
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// Set up the file position
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buf.recordnum += records;
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buf.filepointer += buf.recordlength * records;
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}
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//----------------------------------------------------------------------
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// Command Dispatch
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//----------------------------------------------------------------------
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function executeCommand(command) {
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// Delegate to various commands
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// http://www.xs4all.nl/~fjkraan/comp/apple2faq/app2doscmdfaq.html
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// http://www.textfiles.com/apple/ANATOMY/
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var filename, filename2, args, slot;
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if (monico & MON_C && tty) {
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tty.writeString(command + "\r");
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}
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if (command.match(/^MON([\x20-\x7E]*)/)) {
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// MON[,C][,I][,O] Traces DOS 3.3 commands ('Commands', 'Input' and 'Output')
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args = parseArgs(RegExp.$1, 'ICO');
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if (args.I !== undefined) {
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monico |= MON_I;
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}
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if (args.C !== undefined) {
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monico |= MON_C;
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}
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if (args.O !== undefined) {
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monico |= MON_O;
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}
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} else if (command.match(/^NOMON([\x20-\x7E]*)/)) {
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// NOMON[,C][,I][,O] Cancels tracing of DOS 3.3 commands ('Commands', 'Input' and 'Output')
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args = parseArgs(RegExp.$1, 'ICO');
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if (args.I !== undefined) {
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monico &= ~MON_I;
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}
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if (args.C !== undefined) {
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monico &= ~MON_C;
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}
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if (args.O !== undefined) {
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monico &= ~MON_O;
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}
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} else if (command.match(/^OPEN\s*([\x20-\x2B\x2D-\x7E]+)(,[\x20-\x7E]*)?/)) {
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// OPEN filename[,Llen] Opens a text file.
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filename = RegExp.$1;
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args = parseArgs(RegExp.$2, 'L');
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open(filename, args.L);
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} else if (command.match(/^APPEND\s*([\x20-\x2B\x2D-\x7E]+)(,[\x20-\x7E]*)?/)) {
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// APPEND filename Appends to a text file.
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filename = RegExp.$1;
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args = parseArgs(RegExp.$2);
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append(filename, args.L);
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} else if (command.match(/^CLOSE\s*([\x20-\x2B\x2D-\x7E]+)?(,[\x20-\x7E]*)?/)) {
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// CLOSE [filename] Closes specified (or all) open text files.
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filename = RegExp.$1;
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close(filename);
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} else if (command.match(/^POSITION\s*([\x20-\x2B\x2D-\x7E]+)(,[\x20-\x7E]*)?/)) {
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// POSITION filename[,Rnum] Advances position in text file.
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filename = RegExp.$1;
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args = parseArgs(RegExp.$2, 'R');
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position(filename, args.R);
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} else if (command.match(/^READ\s*([\x20-\x2B\x2D-\x7E]+)(,[\x20-\x7E]*)?/)) {
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// READ filename[,Rnum][,Bbyte] Reads from a text file.
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filename = RegExp.$1;
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args = parseArgs(RegExp.$2, 'RB');
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read(filename, args.R, args.B);
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} else if (command.match(/^WRITE\s*([\x20-\x2B\x2D-\x7E]+)(,[\x20-\x7E]*)?/)) {
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// WRITE filename[,Rnum][,Bbyte] Writes to a text file.
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filename = RegExp.$1;
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args = parseArgs(RegExp.$2, 'RB');
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write(filename, args.R, args.B);
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} else if (command.match(/^DELETE\s*([\x20-\x2B\x2D-\x7E]+)(,[\x20-\x7E]*)?/)) {
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// DELETE filename Delete a file
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filename = RegExp.$1;
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args = parseArgs(RegExp.$2);
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unlink(filename);
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} else if (command.match(/^RENAME\s*([\x20-\x2B\x2D-\x7E]+),\s*([\x20-\x2B\x2D-\x7E]+)(,[\x20-\x7E]*)?/)) {
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// RENAME filename,filename Rename a file
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filename = RegExp.$1;
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filename2 = RegExp.$2;
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args = parseArgs(RegExp.$3);
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rename(filename, filename2);
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} else if (command.match(/^PR#\s*([\x20-\x2B\x2D-\x7E]+)(,[\x20-\x7E]*)?/)) {
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// PR# slot Direct output to slot
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slot = Number(RegExp.$1);
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args = parseArgs(RegExp.$2);
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if (slot === 0) {
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if (tty.setFirmwareActive) { tty.setFirmwareActive(false); }
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} else if (slot === 3) {
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if (tty.setFirmwareActive) { tty.setFirmwareActive(true); }
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} else {
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doserror(DOSErrors.RANGE_ERROR);
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}
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} else if (command.match(/^$/)) {
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// Null command - terminates a READ/WRITE, but doesn't CLOSE
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// (leaves record length intact on open buffer)
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activebuffer = null;
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mode = "";
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} else {
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doserror(DOSErrors.INVALID_OPTION);
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}
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}
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//----------------------------------------------------------------------
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// Install TTY Hooks
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//----------------------------------------------------------------------
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tty_readLine = tty.readLine;
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tty_readChar = tty.readChar;
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tty_writeChar = tty.writeChar;
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tty.readLine = function _dos_readLine(callback, prompt) {
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var string = "", c, data, len, fp, buffer;
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if (mode === "r") {
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// Cache for performance
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data = activebuffer.file;
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len = data.length;
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fp = activebuffer.filepointer;
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if (fp >= len) {
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doserror(DOSErrors.END_OF_DATA);
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}
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buffer = [];
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while (fp < len) {
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// Sequential Access
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c = data[fp];
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fp += 1;
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if (c === "\r" || c === "\n" || c === "\x00") {
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break;
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} else {
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buffer.push(c);
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}
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}
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activebuffer.filepointer = fp;
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string = buffer.join("");
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if (monico & MON_I) {
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tty.writeString(prompt + string + "\r");
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}
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// Non-blocking return
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setTimeout(function() { callback(string); }, 0);
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} else {
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tty_readLine(callback, prompt);
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}
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};
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tty.readChar = function _dos_readChar(callback) {
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var character = "";
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if (mode === "r") {
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if (activebuffer.filepointer >= activebuffer.file.length) {
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doserror(DOSErrors.END_OF_DATA);
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}
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character = activebuffer.file[activebuffer.filepointer];
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activebuffer.filepointer += 1;
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if (monico & MON_I && tty) {
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tty_writeChar(character);
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}
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// Non-blocking return
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setTimeout(function() { callback(character); }, 0);
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} else {
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tty_readChar(callback);
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}
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};
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tty.writeChar = function _dos_writeChar(c) {
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if (commandMode) {
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if (c === "\r") {
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commandMode = false;
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executeCommand(commandBuffer);
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commandBuffer = "";
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} else {
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commandBuffer += c;
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}
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return;
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} else if (c === "\x04") {
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commandBuffer = "";
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commandMode = true;
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return;
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}
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if (mode === "w") {
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var buf, d;
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if (monico & MON_O) {
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tty_writeChar(c);
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}
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buf = activebuffer;
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// Extend file to necessary length
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while (buf.filepointer > buf.file.length) {
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buf.file += "\x00";
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}
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// Append or insert character
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if (buf.filepointer === buf.file.length) {
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buf.file += c;
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} else {
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d = buf.file.substring(0, buf.filepointer);
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d += c;
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d += buf.file.substring(buf.filepointer + 1);
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buf.file = d;
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}
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buf.filepointer += 1;
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} else {
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tty_writeChar(c);
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}
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}; // writeChar
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}
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