apple2js/js/formats/format_utils.ts
Ian Flanigan 910238bf63
Convert cards/disk2.js to Typescript (#54)
* Convert `cards/disk2.js` to Typescript

This is mostly a straightforward conversion of `cards/disk2.js` to
Typescript, with the following exceptions:

*   `setState()` did not restore the drive light state correctly
    because the callback was called with the old `on` value.

*   `setPhase()` did not work for WOZ images.

*   `getBinary()` did not work for `nib` files.

*   `getBase64()` did not work for `nib` files and maybe didn't work
    right at all.

Even with these fixes, local storage still doesn't work correctly.

I have also added several TODOs where methods don't support WOZ disks.

* Convert most uses of `memory` to `Uint8Array`

There are many places in the existing code where we use `Uint8Array`
directly. This change merely makes the `memory` type equivalent to
`Uint8Array`.

This change also changes most ROM data to be read-only in Typescript
to ensure that it is not modified by mistake. This can't be done just
by applying `as const` to the declaration because `Uint8Array`s are
can not be expressed as literals. Instead, we create a new type,
`ReadonlyUint8Array` that drops the mutation methods and makes indexed
access read-only.

See
https://www.growingwiththeweb.com/2020/10/typescript-readonly-typed-arrays.html
for details.

* Tighten types and document `disk2.ts`

While trying to understand the Disk ][ emulation, I tighted the types
and documented the parts that I could, including references to other
sources, like _Understanding the Apple //e_ by Jim Sather.

The one functional change is the addition of the P6 ROM of DOS 3.2 and
earlier. This is automatically selected if the card is initialized for
13 sector disks.
2021-02-07 20:50:50 -08:00

464 lines
13 KiB
TypeScript

/* Copyright 2010-2019 Will Scullin <scullin@scullinsteel.com>
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation. No representations are made about the suitability of this
* software for any purpose. It is provided "as is" without express or
* implied warranty.
*/
import { byte, DiskFormat, memory } from '../types';
import { base64_decode, base64_encode } from '../base64';
import { bytify, debug, toHex } from '../util';
export type Disk = {
format: DiskFormat,
name: string,
volume: byte,
tracks: memory[],
readOnly: boolean,
};
export type Drive = {
format: DiskFormat,
volume: byte,
tracks: memory[],
readOnly: boolean,
dirty: boolean,
}
/**
* DOS 3.3 Physical sector order (index is physical sector, value is DOS sector).
*/
export const DO = [
0x0, 0x7, 0xE, 0x6, 0xD, 0x5, 0xC, 0x4,
0xB, 0x3, 0xA, 0x2, 0x9, 0x1, 0x8, 0xF
];
/**
* DOS 3.3 Logical sector order (index is DOS sector, value is physical sector).
*/
export const _DO = [
0x0, 0xD, 0xB, 0x9, 0x7, 0x5, 0x3, 0x1,
0xE, 0xC, 0xA, 0x8, 0x6, 0x4, 0x2, 0xF
];
/**
* ProDOS Physical sector order (index is physical sector, value is ProDOS sector).
*/
export const PO = [
0x0, 0x8, 0x1, 0x9, 0x2, 0xa, 0x3, 0xb,
0x4, 0xc, 0x5, 0xd, 0x6, 0xe, 0x7, 0xf
];
/**
* ProDOS Logical sector order (index is ProDOS sector, value is physical sector).
*/
export const _PO = [
0x0, 0x2, 0x4, 0x6, 0x8, 0xa, 0xc, 0xe,
0x1, 0x3, 0x5, 0x7, 0x9, 0xb, 0xd, 0xf
];
/**
* DOS 13-sector disk physical sector order (index is disk sector, value is
* physical sector).
*/
export const D13O = [
0x0, 0xa, 0x7, 0x4, 0x1, 0xb, 0x8, 0x5, 0x2, 0xc, 0x9, 0x6, 0x3
];
export const _D13O = [
0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa, 0xb, 0xc
];
const _trans53 = [
0xab, 0xad, 0xae, 0xaf, 0xb5, 0xb6, 0xb7, 0xba,
0xbb, 0xbd, 0xbe, 0xbf, 0xd6, 0xd7, 0xda, 0xdb,
0xdd, 0xde, 0xdf, 0xea, 0xeb, 0xed, 0xee, 0xef,
0xf5, 0xf6, 0xf7, 0xfa, 0xfb, 0xfd, 0xfe, 0xff
];
const _trans62 = [
0x96, 0x97, 0x9a, 0x9b, 0x9d, 0x9e, 0x9f, 0xa6,
0xa7, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb2, 0xb3,
0xb4, 0xb5, 0xb6, 0xb7, 0xb9, 0xba, 0xbb, 0xbc,
0xbd, 0xbe, 0xbf, 0xcb, 0xcd, 0xce, 0xcf, 0xd3,
0xd6, 0xd7, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde,
0xdf, 0xe5, 0xe6, 0xe7, 0xe9, 0xea, 0xeb, 0xec,
0xed, 0xee, 0xef, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6,
0xf7, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff
];
export const detrans62 = [
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
0x00, 0x00, 0x02, 0x03, 0x00, 0x04, 0x05, 0x06,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x08,
0x00, 0x00, 0x00, 0x09, 0x0A, 0x0B, 0x0C, 0x0D,
0x00, 0x00, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13,
0x00, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x1B, 0x00, 0x1C, 0x1D, 0x1E,
0x00, 0x00, 0x00, 0x1F, 0x00, 0x00, 0x20, 0x21,
0x00, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
0x00, 0x00, 0x00, 0x00, 0x00, 0x29, 0x2A, 0x2B,
0x00, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32,
0x00, 0x00, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38,
0x00, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F
];
/**
* From Beneath Apple DOS
*/
export function fourXfour(val: byte): [xx: byte, yy: byte] {
let xx = val & 0xaa;
let yy = val & 0x55;
xx >>= 1;
xx |= 0xaa;
yy |= 0xaa;
return [xx, yy];
}
export function defourXfour(xx: byte, yy: byte): byte {
return ((xx << 1) | 0x01) & yy;
}
export function explodeSector16(volume: byte, track: byte, sector: byte, data: memory) {
let buf = [];
let gap;
/*
* Gap 1/3 (40/0x28 bytes)
*/
if (sector === 0) // Gap 1
gap = 0x80;
else { // Gap 3
gap = track === 0 ? 0x28 : 0x26;
}
for (let idx = 0; idx < gap; idx++) {
buf.push(0xff);
}
/*
* Address Field
*/
const checksum = volume ^ track ^ sector;
buf = buf.concat([0xd5, 0xaa, 0x96]); // Address Prolog D5 AA 96
buf = buf.concat(fourXfour(volume));
buf = buf.concat(fourXfour(track));
buf = buf.concat(fourXfour(sector));
buf = buf.concat(fourXfour(checksum));
buf = buf.concat([0xde, 0xaa, 0xeb]); // Epilog DE AA EB
/*
* Gap 2 (5 bytes)
*/
for (let idx = 0; idx < 0x05; idx++) {
buf.push(0xff);
}
/*
* Data Field
*/
buf = buf.concat([0xd5, 0xaa, 0xad]); // Data Prolog D5 AA AD
const nibbles: byte[] = [];
const ptr2 = 0;
const ptr6 = 0x56;
for (let idx = 0; idx < 0x156; idx++) {
nibbles[idx] = 0;
}
let idx2 = 0x55;
for (let idx6 = 0x101; idx6 >= 0; idx6--) {
let val6 = data[idx6 % 0x100];
let val2: byte = nibbles[ptr2 + idx2];
val2 = (val2 << 1) | (val6 & 1);
val6 >>= 1;
val2 = (val2 << 1) | (val6 & 1);
val6 >>= 1;
nibbles[ptr6 + idx6] = val6;
nibbles[ptr2 + idx2] = val2;
if (--idx2 < 0)
idx2 = 0x55;
}
let last = 0;
for (let idx = 0; idx < 0x156; idx++) {
const val = nibbles[idx];
buf.push(_trans62[last ^ val]);
last = val;
}
buf.push(_trans62[last]);
buf = buf.concat([0xde, 0xaa, 0xeb]); // Epilog DE AA EB
/*
* Gap 3
*/
buf.push(0xff);
return buf;
}
export function explodeSector13(volume: byte, track: byte, sector: byte, data: byte[]) {
let buf = [];
let gap;
/*
* Gap 1/3 (40/0x28 bytes)
*/
if (sector === 0) // Gap 1
gap = 0x80;
else { // Gap 3
gap = track === 0 ? 0x28 : 0x26;
}
for (let idx = 0; idx < gap; idx++) {
buf.push(0xff);
}
/*
* Address Field
*/
const checksum = volume ^ track ^ sector;
buf = buf.concat([0xd5, 0xaa, 0xb5]); // Address Prolog D5 AA B5
buf = buf.concat(fourXfour(volume));
buf = buf.concat(fourXfour(track));
buf = buf.concat(fourXfour(sector));
buf = buf.concat(fourXfour(checksum));
buf = buf.concat([0xde, 0xaa, 0xeb]); // Epilog DE AA EB
/*
* Gap 2 (5 bytes)
*/
for (let idx = 0; idx < 0x05; idx++) {
buf.push(0xff);
}
/*
* Data Field
*/
buf = buf.concat([0xd5, 0xaa, 0xad]); // Data Prolog D5 AA AD
const nibbles = [];
let jdx = 0;
for (let idx = 0x32; idx >= 0; idx--) {
const a5 = data[jdx] >> 3;
const a3 = data[jdx] & 0x07;
jdx++;
const b5 = data[jdx] >> 3;
const b3 = data[jdx] & 0x07;
jdx++;
const c5 = data[jdx] >> 3;
const c3 = data[jdx] & 0x07;
jdx++;
const d5 = data[jdx] >> 3;
const d3 = data[jdx] & 0x07;
jdx++;
const e5 = data[jdx] >> 3;
const e3 = data[jdx] & 0x07;
jdx++;
nibbles[idx + 0x00] = a5;
nibbles[idx + 0x33] = b5;
nibbles[idx + 0x66] = c5;
nibbles[idx + 0x99] = d5;
nibbles[idx + 0xcc] = e5;
nibbles[idx + 0x100] = a3 << 2 | (d3 & 0x4) >> 1 | (e3 & 0x4) >> 2;
nibbles[idx + 0x133] = b3 << 2 | (d3 & 0x2) | (e3 & 0x2) >> 1;
nibbles[idx + 0x166] = c3 << 2 | (d3 & 0x1) << 1 | (e3 & 0x1);
}
nibbles[0xff] = data[jdx] >> 3;
nibbles[0x199] = data[jdx] & 0x07;
let last = 0;
for (let idx = 0x199; idx >= 0x100; idx--) {
const val = nibbles[idx];
buf.push(_trans53[last ^ val]);
last = val;
}
for (let idx = 0x0; idx < 0x100; idx++) {
const val = nibbles[idx];
buf.push(_trans53[last ^ val]);
last = val;
}
buf.push(_trans53[last]);
buf = buf.concat([0xde, 0xaa, 0xeb]); // Epilog DE AA EB
/*
* Gap 3
*/
buf.push(0xff);
return buf;
}
// TODO(flan): Does not work on WOZ disks
export function readSector(drive: Drive, track: byte, sector: byte) {
const _sector = drive.format == 'po' ? _PO[sector] : _DO[sector];
let val, state = 0;
let idx = 0;
let retry = 0;
const cur = drive.tracks[track];
function _readNext() {
const result = cur[idx++];
if (idx >= cur.length) {
idx = 0;
retry++;
}
return result;
}
function _skipBytes(count: number) {
idx += count;
if (idx >= cur.length) {
idx %= cur.length;
retry++;
}
}
let t = 0, s = 0, v = 0, checkSum;
const data = new Uint8Array(256);
while (retry < 4) {
switch (state) {
case 0:
val = _readNext();
state = (val === 0xd5) ? 1 : 0;
break;
case 1:
val = _readNext();
state = (val === 0xaa) ? 2 : 0;
break;
case 2:
val = _readNext();
state = (val === 0x96) ? 3 : (val === 0xad ? 4 : 0);
break;
case 3: // Address
v = defourXfour(_readNext(), _readNext()); // Volume
t = defourXfour(_readNext(), _readNext());
s = defourXfour(_readNext(), _readNext());
checkSum = defourXfour(_readNext(), _readNext());
if (checkSum != (v ^ t ^ s)) {
debug('Invalid header checksum:', toHex(v), toHex(t), toHex(s), toHex(checkSum));
}
_skipBytes(3); // Skip footer
state = 0;
break;
case 4: // Data
if (s === _sector && t === track) {
const data2 = [];
let last = 0;
for (let jdx = 0x55; jdx >= 0; jdx--) {
val = detrans62[_readNext() - 0x80] ^ last;
data2[jdx] = val;
last = val;
}
for (let jdx = 0; jdx < 0x100; jdx++) {
val = detrans62[_readNext() - 0x80] ^ last;
data[jdx] = val;
last = val;
}
checkSum = detrans62[_readNext() - 0x80] ^ last;
if (checkSum) {
debug('Invalid data checksum:', toHex(v), toHex(t), toHex(s), toHex(checkSum));
}
for (let kdx = 0, jdx = 0x55; kdx < 0x100; kdx++) {
data[kdx] <<= 1;
if ((data2[jdx] & 0x01) !== 0) {
data[kdx] |= 0x01;
}
data2[jdx] >>= 1;
data[kdx] <<= 1;
if ((data2[jdx] & 0x01) !== 0) {
data[kdx] |= 0x01;
}
data2[jdx] >>= 1;
if (--jdx < 0) jdx = 0x55;
}
return data;
}
else
_skipBytes(0x159); // Skip data, checksum and footer
state = 0;
break;
default:
break;
}
}
return new Uint8Array();
}
export function jsonEncode(cur: Drive, pretty: boolean) {
// For 'nib', tracks are encoded as strings. For all other formats,
// tracks are arrays of sectors which are encoded as strings.
const data: string[] | string[][] = [];
let format = 'dsk';
for (let t = 0; t < cur.tracks.length; t++) {
data[t] = [];
if (cur.format === 'nib') {
format = 'nib';
data[t] = base64_encode(cur.tracks[t]);
} else {
for (let s = 0; s < 0x10; s++) {
(data[t] as string[])[s] = base64_encode(readSector(cur, t, s));
}
}
}
return JSON.stringify({
'type': format,
'encoding': 'base64',
'volume': cur.volume,
'data': data,
'readOnly': cur.readOnly,
}, undefined, pretty ? ' ' : undefined);
}
export function jsonDecode(data: string) {
const tracks: memory[] = [];
const json = JSON.parse(data);
const v = json.volume;
const readOnly = json.readOnly;
for (let t = 0; t < json.data.length; t++) {
let track: byte[] = [];
for (let s = 0; s < json.data[t].length; s++) {
const _s = 15 - s;
const sector: string = json.data[t][_s];
const d = base64_decode(sector);
track = track.concat(explodeSector16(v, t, s, d));
}
tracks[t] = bytify(track);
}
const cur: Drive = {
volume: v,
format: json.type,
tracks,
readOnly,
dirty: false,
};
return cur;
}