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b647b3c2bb
* CFFA * CFFA multi-disk and write functionaliity. * Clean up multi-devices/partition behavior. * ProDOS WIP * Update against refactored codebase. * WIP * Wait until disks load, show progress. * Don't wait so long to boot floppies. * Forgot to save :|. * Credit.
83 lines
2.5 KiB
JavaScript
83 lines
2.5 KiB
JavaScript
/* Copyright 2010-2019 Will Scullin <scullin@scullinsteel.com>
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*
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* Permission to use, copy, modify, distribute, and sell this software and its
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* documentation for any purpose is hereby granted without fee, provided that
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* the above copyright notice appear in all copies and that both that
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* copyright notice and this permission notice appear in supporting
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* documentation. No representations are made about the suitability of this
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* software for any purpose. It is provided "as is" without express or
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* implied warranty.
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*/
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import BlockVolume from './block';
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import DOS from './do';
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import Nibble from './nib';
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import ProDOS from './po';
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import { numToString, debug } from '../util';
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export default function _2MG(options) {
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var OFFSETS = {
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CREATOR: 0x04,
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FLAGS: 0x0A,
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FORMAT: 0x0C,
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BLOCKS: 0x14,
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DATA_OFFSET: 0x18,
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BYTES: 0x1C,
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};
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var FLAGS = {
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READ_ONLY: 0x80000000,
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VOLUME_VALID: 0x00000100,
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VOLUME_MASK: 0x000000FF
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};
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var { rawData, arrayConstructor } = options;
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var disk;
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var volume = 254;
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// Standard header size is 64 bytes. Make assumptions.
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var prefix = new DataView(rawData);
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var signature = numToString(prefix.getInt32(0x0, true));
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if (signature !== '2IMG') {
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throw new Error('Unrecognized 2mg signature: ' + signature);
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}
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var creator = numToString(prefix.getInt32(OFFSETS.CREATOR, true));
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var format = prefix.getInt32(OFFSETS.FORMAT, true);
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var bytes = prefix.getInt32(OFFSETS.BYTES, true);
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var offset = prefix.getInt32(OFFSETS.DATA_OFFSET, true);
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var flags = prefix.getInt32(OFFSETS.FLAGS, true);
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var readOnly = (flags & FLAGS.READ_ONLY) !== 0;
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if (flags & FLAGS.VOLUME_VALID) {
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volume = flags & FLAGS.VOLUME_MASK;
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}
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debug('created by', creator);
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rawData = rawData.slice(offset, offset + bytes);
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var blockVolume = options.blockVolume || rawData.byteLength >= (800 * 1024);
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options = { rawData, readOnly, volume, arrayConstructor };
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if (blockVolume) {
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disk = new BlockVolume(options);
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} else {
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// Check image format.
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// Sure, it's really 64 bits. But only 2 are actually used.
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switch (format) {
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case 1: // PO
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disk = new ProDOS(options);
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break;
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case 2: // NIB
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disk = new Nibble(options);
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break;
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case 0: // dsk
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default: // Something hinky, assume 'dsk'
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disk = new DOS(options);
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break;
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}
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}
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return disk;
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}
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