apple2js/js/formats/po.ts
2022-07-23 12:00:38 -07:00

45 lines
1.5 KiB
TypeScript

import { explodeSector16, PO } from './format_utils';
import { bytify } from '../util';
import type { byte } from '../types';
import { NibbleDisk, DiskOptions, ENCODING_NIBBLE } from './types';
/**
* Returns a `Disk` object from ProDOS-ordered image data.
* @param options the disk image and options
* @returns A nibblized disk
*/
export default function createDiskFromProDOS(options: DiskOptions) {
const { data, name, side, rawData, volume, readOnly } = options;
const disk: NibbleDisk = {
format: 'po',
encoding: ENCODING_NIBBLE,
name,
side,
volume: volume || 254,
tracks: [],
readOnly: readOnly || false,
};
for (let physical_track = 0; physical_track < 35; physical_track++) {
let track: byte[] = [];
for (let physical_sector = 0; physical_sector < 16; physical_sector++) {
const prodos_sector = PO[physical_sector];
let sector;
if (rawData) {
const off = (16 * physical_track + prodos_sector) * 256;
sector = new Uint8Array(rawData.slice(off, off + 256));
} else if (data) {
sector = data[physical_track][prodos_sector];
} else {
throw new Error('Requires data or rawData');
}
track = track.concat(
explodeSector16(volume, physical_track, physical_sector, sector)
);
}
disk.tracks[physical_track] = bytify(track);
}
return disk;
}