apple2js/js/cards/disk2.ts
Ian Flanigan 7e41c69366
Add a basic write test for WOZ images (#138)
* Add a basic write test for WOZ images

The new test just tries to change some random nibbles at the beginning
of the image and then verifies that the change has been recorded.
This exposed a bug where `q7` was never set to `true` when write mode
was toggled on.

Also, the assumptions and limitations of `moveHead` are more clearly
documented.

* Address comments

* Improved `moveHead` documentation a bit more.
* Removed redundant variable in `readNibble`.
* Refactored `findSector` and commented out the chatty log line.

All tests pass. No lint warnings.
2022-06-23 06:38:36 -07:00

1017 lines
35 KiB
TypeScript
Raw Blame History

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import { base64_encode } from '../base64';
import type {
byte,
Card,
memory,
nibble,
rom,
} from '../types';
import {
FormatWorkerMessage,
FormatWorkerResponse,
NibbleFormat,
DISK_PROCESSED,
DRIVE_NUMBERS,
DriveNumber,
JSONDisk,
ENCODING_NIBBLE,
PROCESS_BINARY,
PROCESS_JSON_DISK,
PROCESS_JSON,
ENCODING_BITSTREAM,
MassStorageData,
} from '../formats/types';
import {
createDisk,
createDiskFromJsonDisk
} from '../formats/create_disk';
import { toHex } from '../util';
import { jsonDecode, jsonEncode, readSector } from '../formats/format_utils';
import { BOOTSTRAP_ROM_16, BOOTSTRAP_ROM_13 } from '../roms/cards/disk2';
import Apple2IO from '../apple2io';
/** Softswitch locations */
const LOC = {
// Disk II Controller Commands
// See Understanding the Apple IIe, Table 9.1
PHASE0OFF: 0x80, // Q0L: Phase 0 OFF
PHASE0ON: 0x81, // Q0H: Phase 0 ON
PHASE1OFF: 0x82, // Q1L: Phase 1 OFF
PHASE1ON: 0x83, // Q1H: Phase 1 ON
PHASE2OFF: 0x84, // Q2L: Phase 2 OFF
PHASE2ON: 0x85, // Q2H: Phase 2 ON
PHASE3OFF: 0x86, // Q3L: Phase 3 OFF
PHASE3ON: 0x87, // Q3H: Phase 3 ON
DRIVEOFF: 0x88, // Q4L: Drives OFF
DRIVEON: 0x89, // Q4H: Selected drive ON
DRIVE1: 0x8A, // Q5L: Select drive 1
DRIVE2: 0x8B, // Q5H: Select drive 2
DRIVEREAD: 0x8C, // Q6L: Shift while writing; read data
DRIVEWRITE: 0x8D, // Q6H: Load while writing; read write protect
DRIVEREADMODE: 0x8E, // Q7L: Read
DRIVEWRITEMODE: 0x8F // Q7H: Write
} as const;
/** Logic state sequencer ROM */
// See Understanding the Apple IIe, Table 9.3 Logic State Sequencer Commands
// CODE OPERATION BEFORE AFTER
// 0 CLR XXXXXXXX 00000000
// 8 NOP ABCDEFGH ABCDEFGH
// 9 SL0 ABCDEFGH BCDEFGH0
// A SR (write protected) ABCDEFGH 11111111
// (not write protected) ABCDEFGH 0ABCDEFG
// B LOAD XXXXXXXX YYYYYYYY
// D SL1 ABCDEFGH BCDEFGH1
const SEQUENCER_ROM_13 = [
// See Understanding the Apple IIe, Figure 9.10 The DOS 3.2 Logic State Sequencer
// Note that the column order here is NOT the same as in Figure 9.10 for Q7 H (Write).
//
// Q7 L (Read) Q7 H (Write)
// Q6 L (Shift) Q6 H (Load) Q6 L (Shift) Q6 H (Load)
// QA L QA H QA L QA H QA L QA H QA L QA H
// 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0
0xD8, 0x18, 0x18, 0x08, 0x0A, 0x0A, 0x0A, 0x0A, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, // 0
0xD8, 0x2D, 0x28, 0x28, 0x0A, 0x0A, 0x0A, 0x0A, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, // 1
0xD8, 0x38, 0x38, 0x38, 0x0A, 0x0A, 0x0A, 0x0A, 0x39, 0x39, 0x39, 0x39, 0x3B, 0x3B, 0x3B, 0x3B, // 2
0xD8, 0x48, 0xD8, 0x48, 0x0A, 0x0A, 0x0A, 0x0A, 0x48, 0x48, 0x48, 0x48, 0x48, 0x48, 0x48, 0x48, // 3
0xD8, 0x58, 0xD8, 0x58, 0x0A, 0x0A, 0x0A, 0x0A, 0x58, 0x58, 0x58, 0x58, 0x58, 0x58, 0x58, 0x58, // 4
0xD8, 0x68, 0xD8, 0x68, 0x0A, 0x0A, 0x0A, 0x0A, 0x68, 0x68, 0x68, 0x68, 0x68, 0x68, 0x68, 0x68, // 5
0xD8, 0x78, 0xD8, 0x78, 0x0A, 0x0A, 0x0A, 0x0A, 0x78, 0x78, 0x78, 0x78, 0x78, 0x78, 0x78, 0x78, // 6
0xD8, 0x88, 0xD8, 0x88, 0x0A, 0x0A, 0x0A, 0x0A, 0x08, 0x08, 0x88, 0x88, 0x08, 0x08, 0x88, 0x88, // 7
0xD8, 0x98, 0xD8, 0x98, 0x0A, 0x0A, 0x0A, 0x0A, 0x98, 0x98, 0x98, 0x98, 0x98, 0x98, 0x98, 0x98, // 8
0xD8, 0x09, 0xD8, 0xA8, 0x0A, 0x0A, 0x0A, 0x0A, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, // 9
0xCD, 0xBD, 0xD8, 0xB8, 0x0A, 0x0A, 0x0A, 0x0A, 0xB9, 0xB9, 0xB9, 0xB9, 0xBB, 0xBB, 0xBB, 0xBB, // A
0xD9, 0x39, 0xD8, 0xC8, 0x0A, 0x0A, 0x0A, 0x0A, 0xC8, 0xC8, 0xC8, 0xC8, 0xC8, 0xC8, 0xC8, 0xC8, // B
0xD9, 0xD9, 0xD8, 0xA0, 0x0A, 0x0A, 0x0A, 0x0A, 0xD8, 0xD8, 0xD8, 0xD8, 0xD8, 0xD8, 0xD8, 0xD8, // C
0x1D, 0x0D, 0xE8, 0xE8, 0x0A, 0x0A, 0x0A, 0x0A, 0xE8, 0xE8, 0xE8, 0xE8, 0xE8, 0xE8, 0xE8, 0xE8, // D
0xFD, 0xFD, 0xF8, 0xF8, 0x0A, 0x0A, 0x0A, 0x0A, 0xF8, 0xF8, 0xF8, 0xF8, 0xF8, 0xF8, 0xF8, 0xF8, // E
0xDD, 0x4D, 0xE0, 0xE0, 0x0A, 0x0A, 0x0A, 0x0A, 0x88, 0x88, 0x08, 0x08, 0x88, 0x88, 0x08, 0x08 // F
] as const;
const SEQUENCER_ROM_16 = [
// See Understanding the Apple IIe, Figure 9.11 The DOS 3.3 Logic State Sequencer
// Note that the column order here is NOT the same as in Figure 9.11 for Q7 H (Write).
//
// Q7 L (Read) Q7 H (Write)
// Q6 L (Shift) Q6 H (Load) Q6 L (Shift) Q6 H (Load)
// QA L QA H QA L QA H QA L QA H QA L QA H
// 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0
0x18, 0x18, 0x18, 0x18, 0x0A, 0x0A, 0x0A, 0x0A, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, // 0
0x2D, 0x2D, 0x38, 0x38, 0x0A, 0x0A, 0x0A, 0x0A, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, // 1
0xD8, 0x38, 0x08, 0x28, 0x0A, 0x0A, 0x0A, 0x0A, 0x39, 0x39, 0x39, 0x39, 0x3B, 0x3B, 0x3B, 0x3B, // 2
0xD8, 0x48, 0x48, 0x48, 0x0A, 0x0A, 0x0A, 0x0A, 0x48, 0x48, 0x48, 0x48, 0x48, 0x48, 0x48, 0x48, // 3
0xD8, 0x58, 0xD8, 0x58, 0x0A, 0x0A, 0x0A, 0x0A, 0x58, 0x58, 0x58, 0x58, 0x58, 0x58, 0x58, 0x58, // 4
0xD8, 0x68, 0xD8, 0x68, 0x0A, 0x0A, 0x0A, 0x0A, 0x68, 0x68, 0x68, 0x68, 0x68, 0x68, 0x68, 0x68, // 5
0xD8, 0x78, 0xD8, 0x78, 0x0A, 0x0A, 0x0A, 0x0A, 0x78, 0x78, 0x78, 0x78, 0x78, 0x78, 0x78, 0x78, // 6
0xD8, 0x88, 0xD8, 0x88, 0x0A, 0x0A, 0x0A, 0x0A, 0x08, 0x08, 0x88, 0x88, 0x08, 0x08, 0x88, 0x88, // 7
0xD8, 0x98, 0xD8, 0x98, 0x0A, 0x0A, 0x0A, 0x0A, 0x98, 0x98, 0x98, 0x98, 0x98, 0x98, 0x98, 0x98, // 8
0xD8, 0x29, 0xD8, 0xA8, 0x0A, 0x0A, 0x0A, 0x0A, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, // 9
0xCD, 0xBD, 0xD8, 0xB8, 0x0A, 0x0A, 0x0A, 0x0A, 0xB9, 0xB9, 0xB9, 0xB9, 0xBB, 0xBB, 0xBB, 0xBB, // A
0xD9, 0x59, 0xD8, 0xC8, 0x0A, 0x0A, 0x0A, 0x0A, 0xC8, 0xC8, 0xC8, 0xC8, 0xC8, 0xC8, 0xC8, 0xC8, // B
0xD9, 0xD9, 0xD8, 0xA0, 0x0A, 0x0A, 0x0A, 0x0A, 0xD8, 0xD8, 0xD8, 0xD8, 0xD8, 0xD8, 0xD8, 0xD8, // C
0xD8, 0x08, 0xE8, 0xE8, 0x0A, 0x0A, 0x0A, 0x0A, 0xE8, 0xE8, 0xE8, 0xE8, 0xE8, 0xE8, 0xE8, 0xE8, // D
0xFD, 0xFD, 0xF8, 0xF8, 0x0A, 0x0A, 0x0A, 0x0A, 0xF8, 0xF8, 0xF8, 0xF8, 0xF8, 0xF8, 0xF8, 0xF8, // E
0xDD, 0x4D, 0xE0, 0xE0, 0x0A, 0x0A, 0x0A, 0x0A, 0x88, 0x88, 0x08, 0x08, 0x88, 0x88, 0x08, 0x08 // F
] as const;
type LssClockCycle = 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7;
type Phase = 0 | 1 | 2 | 3;
/**
* How far the head moves, in quarter tracks, when in phase X and phase Y is
* activated. For example, if in phase 0 (top row), turning on phase 3 would
* step backwards a quarter track while turning on phase 2 would step forwards
* a half track.
*
* Note that this emulation is highly simplified as it only takes into account
* the order that coils are powered on and ignores when they are powered off.
* The actual hardware allows for multiple coils to be powered at the same time
* providing different levels of torque on the head arm. Along with that, the
* RWTS uses a complex delay system to drive the coils faster based on expected
* head momentum.
*
* Examining the https://computerhistory.org/blog/apple-ii-dos-source-code/,
* one finds that the SEEK routine on line 4831 of `appdos31.lst`. It uses
* `ONTABLE` and `OFFTABLE` (each 12 bytes) to know exactly how many
* microseconds to power on/off each coil as the head accelerates. At the end,
* the final coil is left powered on 9.5 milliseconds to ensure the head has
* settled.
*
* https://embeddedmicro.weebly.com/apple-2iie.html shows traces of the boot
* seek (which is slightly different) and a regular seek.
*/
const PHASE_DELTA = [
[0, 1, 2, -1],
[-1, 0, 1, 2],
[-2, -1, 0, 1],
[1, -2, -1, 0]
] as const;
export interface Callbacks {
driveLight: (drive: DriveNumber, on: boolean) => void;
dirty: (drive: DriveNumber, dirty: boolean) => void;
label: (drive: DriveNumber, name?: string, side?: string) => void;
}
/** Common information for Nibble and WOZ disks. */
interface BaseDrive {
/** Current disk format. */
format: NibbleFormat;
/** Current disk volume number. */
volume: byte;
/** Displayed disk name */
name: string;
/** (Optional) Disk side (Front/Back, A/B) */
side?: string | undefined;
/** Quarter track position of read/write head. */
track: byte;
/** Position of the head on the track. */
head: byte;
/** Current active coil in the head stepper motor. */
phase: Phase;
/** Whether the drive write protect is on. */
readOnly: boolean;
/** Whether the drive has been written to since it was loaded. */
dirty: boolean;
}
/** WOZ format track data from https://applesaucefdc.com/woz/reference2/. */
interface WozDrive extends BaseDrive {
/** Woz encoding */
encoding: typeof ENCODING_BITSTREAM;
/** Maps quarter tracks to data in rawTracks; `0xFF` = random garbage. */
trackMap: byte[];
/** Unique track bitstreams. The index is arbitrary; it is NOT the track number. */
rawTracks: Uint8Array[];
}
/** Nibble format track data. */
interface NibbleDrive extends BaseDrive {
/** Nibble encoding */
encoding: typeof ENCODING_NIBBLE;
/** Nibble data. The index is the track number. */
tracks: memory[];
}
type Drive = WozDrive | NibbleDrive;
function isNibbleDrive(drive: Drive): drive is NibbleDrive {
return drive.encoding === ENCODING_NIBBLE;
}
function isWozDrive(drive: Drive): drive is WozDrive {
return drive.encoding === ENCODING_BITSTREAM;
}
interface DriveState {
format: NibbleFormat;
encoding: typeof ENCODING_BITSTREAM | typeof ENCODING_NIBBLE;
volume: byte;
name: string;
side?: string | undefined;
tracks: memory[];
track: byte;
head: byte;
phase: Phase;
readOnly: boolean;
dirty: boolean;
trackMap: number[];
rawTracks: Uint8Array[];
}
interface State {
drives: DriveState[];
skip: number;
latch: number;
writeMode: boolean;
on: boolean;
drive: DriveNumber;
}
function getDriveState(drive: Drive): DriveState {
const result: DriveState = {
format: drive.format,
encoding: drive.encoding,
volume: drive.volume,
name: drive.name,
side: drive.side,
tracks: [],
track: drive.track,
head: drive.head,
phase: drive.phase,
readOnly: drive.readOnly,
dirty: drive.dirty,
trackMap: [],
rawTracks: [],
};
if (isNibbleDrive(drive)) {
for (let idx = 0; idx < drive.tracks.length; idx++) {
result.tracks.push(new Uint8Array(drive.tracks[idx]));
}
}
if (isWozDrive(drive)) {
result.trackMap = [...drive.trackMap];
for (let idx = 0; idx < drive.rawTracks.length; idx++) {
result.rawTracks.push(new Uint8Array(drive.rawTracks[idx]));
}
}
return result;
}
function setDriveState(state: DriveState) {
let result: Drive;
if (state.encoding === ENCODING_NIBBLE) {
result = {
format: state.format,
encoding: ENCODING_NIBBLE,
volume: state.volume,
name: state.name,
side: state.side,
tracks: [],
track: state.track,
head: state.head,
phase: state.phase,
readOnly: state.readOnly,
dirty: state.dirty,
};
for (let idx = 0; idx < state.tracks.length; idx++) {
result.tracks.push(new Uint8Array(state.tracks[idx]));
}
} else {
result = {
format: state.format,
encoding: ENCODING_BITSTREAM,
volume: state.volume,
name: state.name,
side: state.side,
track: state.track,
head: state.head,
phase: state.phase,
readOnly: state.readOnly,
dirty: state.dirty,
trackMap: [...state.trackMap],
rawTracks: [],
};
for (let idx = 0; idx < state.rawTracks.length; idx++) {
result.rawTracks.push(new Uint8Array(state.rawTracks[idx]));
}
}
return result;
}
/**
* Emulates the 16-sector and 13-sector versions of the Disk ][ drive and controller.
*/
export default class DiskII implements Card<State> {
private drives: Drive[] = [
{ // Drive 1
format: 'dsk',
encoding: ENCODING_NIBBLE,
volume: 254,
name: 'Disk 1',
tracks: [],
track: 0,
head: 0,
phase: 0,
readOnly: false,
dirty: false,
},
{ // Drive 2
format: 'dsk',
encoding: ENCODING_NIBBLE,
volume: 254,
name: 'Disk 2',
tracks: [],
track: 0,
head: 0,
phase: 0,
readOnly: false,
dirty: false,
}];
/**
* When `1`, the next nibble will be available for read; when `0`,
* the card is pretending to wait for data to be shifted in by the
* sequencer.
*/
private skip = 0;
/** Last data written by the CPU to card softswitch 0x8D. */
private bus = 0;
/** Drive data register. */
private latch = 0;
/** Drive off timeout id or null. */
private offTimeout: number | null = null;
/** Q6 (Shift/Load): Used by WOZ disks. */
private q6 = 0;
/** Q7 (Read/Write): Used by WOZ disks. */
private q7: boolean = false;
/** Q7 (Read/Write): Used by Nibble disks. */
private writeMode = false;
/** Whether the selected drive is on. */
private on = false;
/** Current drive number (1, 2). */
private drive: DriveNumber = 1;
/** Current drive object. */
private cur = this.drives[this.drive - 1];
/** Nibbles read this on cycle */
private nibbleCount = 0;
/** Q0-Q3: Coil states. */
private q = [false, false, false, false];
/** The 8-cycle LSS clock. */
private clock: LssClockCycle = 0;
/** Current CPU cycle count. */
private lastCycles = 0;
/** Current state of the Logic State Sequencer. */
private state: nibble = 0;
/**
* Number of zeros read in a row. The Disk ][ can only read two zeros in a
* row reliably; above that and the drive starts reporting garbage. See
* "Freaking Out Like a MC3470" in the WOZ spec.
*/
private zeros = 0;
/** Contents of the P5 ROM at 0xCnXX. */
private bootstrapRom: rom;
/** Contents of the P6 ROM. */
private sequencerRom: typeof SEQUENCER_ROM_16 | typeof SEQUENCER_ROM_13;
private worker: Worker;
/** Builds a new Disk ][ card. */
constructor(private io: Apple2IO, private callbacks: Callbacks, private sectors = 16) {
this.debug('Disk ][');
this.lastCycles = this.io.cycles();
this.bootstrapRom = this.sectors === 16 ? BOOTSTRAP_ROM_16 : BOOTSTRAP_ROM_13;
this.sequencerRom = this.sectors === 16 ? SEQUENCER_ROM_16 : SEQUENCER_ROM_13;
// From the example in UtA2e, p. 9-29, col. 1, para. 1., this is
// essentially the start of the sequencer loop and produces
// correctly synced nibbles immediately. Starting at state 0
// would introduce a spurrious 1 in the latch at the beginning,
// which requires reading several more sync bytes to sync up.
this.state = 2;
this.initWorker();
}
private debug(..._args: unknown[]) {
// debug(..._args);
}
public head(): number {
return this.cur.head;
}
/**
* Spin the disk under the read/write head for WOZ images.
*
* This implementation emulates every clock cycle of the 2 MHz
* sequencer since the last time it was called in order to
* determine the current state. Because this is called on
* every access to the softswitches, the data in the latch
* will be correct on every read.
*
* The emulation of the disk makes a few simplifying assumptions:
*
* * The motor turns on instantly.
* * The head moves tracks instantly.
* * The length (in bits) of each track of the WOZ image
* represents one full rotation of the disk and that each
* bit is evenly spaced.
* * Writing will not change the track length. This means
* that short tracks stay short.
* * The read head picks up the next bit when the sequencer
* clock === 4.
* * Head position X on track T is equivalent to head position
* X on track T. (This is not the recommendation in the WOZ
* spec.)
* * Unspecified tracks contain a single zero bit. (A very
* short track, indeed!)
* * Two zero bits are sufficient to cause the MC3470 to freak
* out. When freaking out, it returns 0 and 1 with equal
* probability.
* * Any softswitch changes happen before `moveHead`. This is
* important because it means that if the clock is ever
* advanced more than one cycle between calls, the
* softswitch changes will appear to happen at the very
* beginning, not just before the last cycle.
*/
private moveHead() {
// TODO(flan): Short-circuit if the drive is not on.
const cycles = this.io.cycles();
// Spin the disk the number of elapsed cycles since last call
let workCycles = (cycles - this.lastCycles) * 2;
this.lastCycles = cycles;
if (!isWozDrive(this.cur)) {
return;
}
const track =
this.cur.rawTracks[this.cur.trackMap[this.cur.track]] || [0];
while (workCycles-- > 0) {
let pulse: number = 0;
if (this.clock === 4) {
pulse = track[this.cur.head];
if (!pulse) {
// More than 2 zeros can not be read reliably.
if (++this.zeros > 2) {
pulse = Math.random() >= 0.5 ? 1 : 0;
}
} else {
this.zeros = 0;
}
}
let idx = 0;
idx |= pulse ? 0x00 : 0x01;
idx |= this.latch & 0x80 ? 0x02 : 0x00;
idx |= this.q6 ? 0x04 : 0x00;
idx |= this.q7 ? 0x08 : 0x00;
idx |= this.state << 4;
const command = this.sequencerRom[idx];
this.debug(`clock: ${this.clock} state: ${toHex(this.state)} pulse: ${pulse} command: ${toHex(command)} q6: ${this.q6} latch: ${toHex(this.latch)}`);
switch (command & 0xf) {
case 0x0: // CLR
this.latch = 0;
break;
case 0x8: // NOP
break;
case 0x9: // SL0
this.latch = (this.latch << 1) & 0xff;
break;
case 0xA: // SR
this.latch >>= 1;
if (this.cur.readOnly) {
this.latch |= 0x80;
}
break;
case 0xB: // LD
this.latch = this.bus;
this.debug('Loading', toHex(this.latch), 'from bus');
break;
case 0xD: // SL1
this.latch = ((this.latch << 1) | 0x01) & 0xff;
break;
default:
this.debug(`unknown command: ${toHex(command & 0xf)}`);
}
this.state = (command >> 4 & 0xF) as nibble;
if (this.clock === 4) {
if (this.on) {
if (this.q7) {
track[this.cur.head] = this.state & 0x8 ? 0x01 : 0x00;
this.debug('Wrote', this.state & 0x8 ? 0x01 : 0x00);
}
if (++this.cur.head >= track.length) {
this.cur.head = 0;
}
}
}
if (++this.clock > 7) {
this.clock = 0;
}
}
}
// Only called for non-WOZ disks
private readWriteNext() {
if (!isNibbleDrive(this.cur)) {
return;
}
if (this.on && (this.skip || this.writeMode)) {
const track = this.cur.tracks[this.cur.track >> 2];
if (track && track.length) {
if (this.cur.head >= track.length) {
this.cur.head = 0;
}
if (this.writeMode) {
if (!this.cur.readOnly) {
track[this.cur.head] = this.bus;
if (!this.cur.dirty) {
this.updateDirty(this.drive, true);
}
}
} else {
this.latch = track[this.cur.head];
}
++this.cur.head;
}
} else {
this.latch = 0;
}
this.skip = (++this.skip % 2);
}
/**
* Sets whether the head positioning stepper motor coil for the given
* phase is on or off. Normally, the motor must be stepped two phases
* per track. Half tracks can be written by stepping only once; quarter
* tracks by activating two neighboring coils at once.
*/
private setPhase(phase: Phase, on: boolean) {
// According to Sather, UtA2e, p. 9-12, Drive On/Off and Drive
// Select:
// Turning a drive on ($C089,X) [...]:
// 1. [...]
// 5. [...] enables head positioning [...]
//
// Therefore do nothing if no drive is on.
if (!this.on) {
this.debug(`ignoring phase ${phase}${on ? ' on' : ' off'}`);
return;
}
this.debug(`phase ${phase}${on ? ' on' : ' off'}`);
if (on) {
this.cur.track += PHASE_DELTA[this.cur.phase][phase] * 2;
this.cur.phase = phase;
}
// The emulator clamps the track to the valid track range available
// in the image, but real Disk II drives can seek past track 34 by
// at least a half track, usually a full track. Some 3rd party
// drives can seek to track 39.
const maxTrack = isNibbleDrive(this.cur)
? this.cur.tracks.length * 4 - 1
: this.cur.trackMap.length - 1;
if (this.cur.track > maxTrack) {
this.cur.track = maxTrack;
}
if (this.cur.track < 0x0) {
this.cur.track = 0x0;
}
// debug(
// 'Drive', _drive, 'track', toHex(_cur.track >> 2) + '.' + (_cur.track & 0x3),
// '(' + toHex(_cur.track) + ')',
// '[' + phase + ':' + (on ? 'on' : 'off') + ']');
this.q[phase] = on;
}
private access(off: byte, val?: byte) {
let result = 0;
const readMode = val === undefined;
switch (off & 0x8f) {
case LOC.PHASE0OFF: // 0x00
this.setPhase(0, false);
break;
case LOC.PHASE0ON: // 0x01
this.setPhase(0, true);
break;
case LOC.PHASE1OFF: // 0x02
this.setPhase(1, false);
break;
case LOC.PHASE1ON: // 0x03
this.setPhase(1, true);
break;
case LOC.PHASE2OFF: // 0x04
this.setPhase(2, false);
break;
case LOC.PHASE2ON: // 0x05
this.setPhase(2, true);
break;
case LOC.PHASE3OFF: // 0x06
this.setPhase(3, false);
break;
case LOC.PHASE3ON: // 0x07
this.setPhase(3, true);
break;
case LOC.DRIVEOFF: // 0x08
if (!this.offTimeout) {
if (this.on) {
// TODO(flan): This is fragile because it relies on
// wall-clock time instead of emulator time.
this.offTimeout = window.setTimeout(() => {
this.debug('Drive Off');
this.on = false;
this.callbacks.driveLight(this.drive, false);
this.debug('nibbles read', this.nibbleCount);
}, 1000);
}
}
break;
case LOC.DRIVEON: // 0x09
if (this.offTimeout) {
// TODO(flan): Fragile—see above
window.clearTimeout(this.offTimeout);
this.offTimeout = null;
}
if (!this.on) {
this.debug('Drive On');
this.nibbleCount = 0;
this.on = true;
this.lastCycles = this.io.cycles();
this.callbacks.driveLight(this.drive, true);
}
break;
case LOC.DRIVE1: // 0x0a
this.debug('Disk 1');
this.drive = 1;
this.cur = this.drives[this.drive - 1];
if (this.on) {
this.callbacks.driveLight(2, false);
this.callbacks.driveLight(1, true);
}
break;
case LOC.DRIVE2: // 0x0b
this.debug('Disk 2');
this.drive = 2;
this.cur = this.drives[this.drive - 1];
if (this.on) {
this.callbacks.driveLight(1, false);
this.callbacks.driveLight(2, true);
}
break;
case LOC.DRIVEREAD: // 0x0c (Q6L) Shift
this.q6 = 0;
if (this.writeMode) {
this.debug('clearing _q6/SHIFT');
}
if (isNibbleDrive(this.cur)) {
this.readWriteNext();
}
break;
case LOC.DRIVEWRITE: // 0x0d (Q6H) LOAD
this.q6 = 1;
if (this.writeMode) {
this.debug('setting _q6/LOAD');
}
if (isNibbleDrive(this.cur)) {
if (readMode && !this.writeMode) {
if (this.cur.readOnly) {
this.latch = 0xff;
this.debug('Setting readOnly');
} else {
this.latch = this.latch >> 1;
this.debug('Clearing readOnly');
}
}
}
break;
case LOC.DRIVEREADMODE: // 0x0e (Q7L)
this.debug('Read Mode');
this.q7 = false;
this.writeMode = false;
break;
case LOC.DRIVEWRITEMODE: // 0x0f (Q7H)
this.debug('Write Mode');
this.q7 = true;
this.writeMode = true;
break;
default:
break;
}
this.moveHead();
if (readMode) {
// According to UtAIIe, p. 9-13 to 9-14, any even address can be
// used to read the data register onto the CPU bus, although some
// also cause conflicts with the disk controller commands.
if ((off & 0x01) === 0) {
result = this.latch;
if (result & 0x80) {
this.nibbleCount++;
}
} else {
result = 0;
}
} else {
// It's not explicitly stated, but writes to any address set the
// data register.
this.bus = val;
}
return result;
}
private updateDirty(drive: DriveNumber, dirty: boolean) {
this.drives[drive - 1].dirty = dirty;
if (this.callbacks.dirty) {
this.callbacks.dirty(drive, dirty);
}
}
ioSwitch(off: byte, val?: byte) {
return this.access(off, val);
}
read(_page: byte, off: byte) {
return this.bootstrapRom[off];
}
write() {
// not writable
}
reset() {
if (this.on) {
this.callbacks.driveLight(this.drive, false);
this.writeMode = false;
this.on = false;
this.drive = 1;
this.cur = this.drives[this.drive - 1];
}
for (let idx = 0; idx < 4; idx++) {
this.q[idx] = false;
}
}
tick() {
this.moveHead();
}
getState(): State {
// TODO(flan): This does not accurately save state. It's missing
// all of the state for WOZ disks and the current status of the
// bus.
const result = {
drives: [] as DriveState[],
skip: this.skip,
latch: this.latch,
writeMode: this.writeMode,
on: this.on,
drive: this.drive
};
this.drives.forEach(function (drive, idx) {
result.drives[idx] = getDriveState(drive);
});
return result;
}
setState(state: State) {
this.skip = state.skip;
this.latch = state.latch;
this.writeMode = state.writeMode;
this.on = state.on;
this.drive = state.drive;
for (const d of DRIVE_NUMBERS) {
const idx = d - 1;
this.drives[idx] = setDriveState(state.drives[idx]);
const { name, side, dirty } = state.drives[idx];
this.callbacks.label(d, name, side);
this.callbacks.driveLight(d, this.on);
this.callbacks.dirty(d, dirty);
}
this.cur = this.drives[this.drive - 1];
}
getMetadata(driveNo: DriveNumber) {
const drive = this.drives[driveNo - 1];
return {
format: drive.format,
volume: drive.volume,
track: drive.track,
head: drive.head,
phase: drive.phase,
readOnly: drive.readOnly,
dirty: drive.dirty
};
}
// TODO(flan): Does not work on WOZ disks
rwts(disk: DriveNumber, track: byte, sector: byte) {
const cur = this.drives[disk - 1];
if (!isNibbleDrive(cur)) {
throw new Error('Can\'t read WOZ disks');
}
return readSector(cur, track, sector);
}
/** Sets the data for `drive` from `disk`, which is expected to be JSON. */
// TODO(flan): This implementation is not very safe.
setDisk(drive: DriveNumber, jsonDisk: JSONDisk) {
if (this.worker) {
const message: FormatWorkerMessage = {
type: PROCESS_JSON_DISK,
payload: {
drive,
jsonDisk
},
};
this.worker.postMessage(message);
return true;
} else {
const disk = createDiskFromJsonDisk(jsonDisk);
if (disk) {
const cur = this.drives[drive - 1];
Object.assign(cur, disk);
this.updateDirty(drive, false);
this.callbacks.label(drive, disk.name, disk.side);
return true;
}
}
return false;
}
getJSON(drive: DriveNumber, pretty: boolean = false) {
const cur = this.drives[drive - 1];
if (!isNibbleDrive(cur)) {
throw new Error('Can\'t save WOZ disks to JSON');
}
return jsonEncode(cur, pretty);
}
setJSON(drive: DriveNumber, json: string) {
if (this.worker) {
const message: FormatWorkerMessage = {
type: PROCESS_JSON,
payload: {
drive,
json
},
};
this.worker.postMessage(message);
} else {
const cur = this.drives[drive - 1];
Object.assign(cur, jsonDecode(json));
}
return true;
}
setBinary(drive: DriveNumber, name: string, fmt: NibbleFormat, rawData: ArrayBuffer) {
const readOnly = false;
const volume = 254;
const options = {
name,
rawData,
readOnly,
volume,
};
if (this.worker) {
const message: FormatWorkerMessage = {
type: PROCESS_BINARY,
payload: {
drive,
fmt,
options,
}
};
this.worker.postMessage(message);
return true;
} else {
const disk = createDisk(fmt, options);
if (disk) {
const cur = this.drives[drive - 1];
const { name, side } = cur;
Object.assign(cur, disk);
this.updateDirty(drive, true);
this.callbacks.label(drive, name, side);
return true;
}
}
return false;
}
initWorker() {
if (!window.Worker) {
return;
}
this.worker = new Worker('dist/format_worker.bundle.js');
this.worker.addEventListener('message', (message: MessageEvent<FormatWorkerResponse>) => {
const { data } = message;
switch (data.type) {
case DISK_PROCESSED:
{
const { drive, disk } = data.payload;
if (disk) {
const cur = this.drives[drive - 1];
Object.assign(cur, disk);
const { name, side } = cur;
this.updateDirty(drive, true);
this.callbacks.label(drive, name, side);
}
}
break;
}
});
}
// TODO(flan): Does not work with WOZ disks
getBinary(drive: DriveNumber): MassStorageData | null {
const cur = this.drives[drive - 1];
if (!isNibbleDrive(cur)) {
return null;
}
// TODO(flan): Assumes 16-sectors
const len = (16 * cur.tracks.length * 256);
const data = new Uint8Array(len);
let idx = 0;
for (let t = 0; t < cur.tracks.length; t++) {
if (cur.format === 'nib') {
data.set(cur.tracks[t], idx);
idx += cur.tracks[t].length;
} else {
for (let s = 0; s < 0x10; s++) {
const sector = readSector(cur, t, s);
data.set(sector, idx);
idx += sector.length;
}
}
}
return {
ext: 'dsk',
name: cur.name,
data: data.buffer
};
}
// TODO(flan): Does not work with WOZ disks
getBase64(drive: DriveNumber) {
const cur = this.drives[drive - 1];
if (!isNibbleDrive(cur)) {
return null;
}
const data: string[][] | string[] = [];
for (let t = 0; t < cur.tracks.length; t++) {
if (cur.format === 'nib') {
data[t] = base64_encode(cur.tracks[t]);
} else {
const track: string[] = [];
for (let s = 0; s < 0x10; s++) {
track[s] = base64_encode(readSector(cur, t, s));
}
data[t] = track;
}
}
return data;
}
}