Add tests for WOZ disks (#136)

* Add a test for the dirty callback on writes

This new test just checks that a clean disk becomes dirty after a
write _and_ that the dirty callback is fired.

* Add tests for WOZ disks

The new tests verify the basic read behavior of the state sequencer on
well-behaved disks, including sync bytes and so on.  Write tests are
still to come.

There's also a change to the Woz format to return the info chunk data
as well.

js/cards/disk2.ts

@@ -1,4 +1,4 @@
-import { base64_encode} from '../base64';
+import { base64_encode } from '../base64';
 import type {
     byte,
     Card,
@@ -28,7 +28,7 @@ import {
     createDiskFromJsonDisk
 } from '../formats/create_disk';
 
-import { debug, toHex } from '../util';
+import { toHex } from '../util';
 import { jsonDecode, jsonEncode, readSector } from '../formats/format_utils';
 
 import { BOOTSTRAP_ROM_16, BOOTSTRAP_ROM_13 } from '../roms/cards/disk2';
@@ -201,7 +201,7 @@ interface NibbleDrive extends BaseDrive {
 
 type Drive = WozDrive | NibbleDrive;
 
-function isNibbleDrive(drive: Drive): drive is NibbleDrive  {
+function isNibbleDrive(drive: Drive): drive is NibbleDrive {
     return drive.encoding === ENCODING_NIBBLE;
 }
 
@@ -395,12 +395,18 @@ export default class DiskII implements Card<State> {
         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.apply(this, arguments);
+        // debug(..._args);
     }
 
     // Only used for WOZ disks
@@ -422,7 +428,7 @@ export default class DiskII implements Card<State> {
             if (this.clock === 4) {
                 pulse = track[this.cur.head];
                 if (!pulse) {
-                    // More that 2 zeros can not be read reliably.
+                    // More than 2 zeros can not be read reliably.
                     if (++this.zeros > 2) {
                         pulse = Math.random() >= 0.5 ? 1 : 0;
                     }
@@ -440,9 +446,7 @@ export default class DiskII implements Card<State> {
 
             const command = this.sequencerRom[idx];
 
-            if (this.on && this.q7) {
-                debug('clock:', this.clock, 'command:', toHex(command), 'q6:', this.q6);
-            }
+            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
@@ -461,11 +465,13 @@ export default class DiskII implements Card<State> {
                     break;
                 case 0xB: // LD
                     this.latch = this.bus;
-                    debug('Loading', toHex(this.latch), 'from 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;
 
@@ -473,7 +479,7 @@ export default class DiskII implements Card<State> {
                 if (this.on) {
                     if (this.q7) {
                         track[this.cur.head] = this.state & 0x8 ? 0x01 : 0x00;
-                        debug('Wrote', this.state & 0x8 ? 0x01 : 0x00);
+                        this.debug('Wrote', this.state & 0x8 ? 0x01 : 0x00);
                     }
 
                     if (++this.cur.head >= track.length) {
@@ -544,6 +550,10 @@ export default class DiskII implements Card<State> {
             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;

js/formats/types.ts

@@ -1,5 +1,6 @@
 import type { byte, memory, MemberOf, word } from '../types';
 import type { GamepadConfiguration } from '../ui/types';
+import { InfoChunk } from './woz';
 
 export const DRIVE_NUMBERS = [1, 2] as const;
 export type DriveNumber = MemberOf<typeof DRIVE_NUMBERS>;
@@ -70,6 +71,7 @@ export interface WozDisk extends FloppyDisk {
     encoding: typeof ENCODING_BITSTREAM;
     trackMap: number[];
     rawTracks: Uint8Array[];
+    info: InfoChunk | undefined;
 }
 
 export interface BlockDisk extends Disk {

js/formats/woz.ts

@@ -155,6 +155,9 @@ export class TrksChunk2 extends TrksChunk {
             const end = start + trk.blockCount * 512;
             const slice = bits.slice(start, end);
             const trackData = new Uint8Array(slice);
+            if (trackNo === 0) {
+                // debug(`First bytes: ${toHex(trackData[0])} ${toHex(trackData[1])} ${toHex(trackData[2])} ${toHex(trackData[3])}`);
+            }
             for (let jdx = 0; jdx < trk.bitCount; jdx++) {
                 const byteIndex = jdx >> 3;
                 const bitIndex = 7 - (jdx & 0x07);
@@ -284,9 +287,9 @@ export default function createDiskFromWoz(options: DiskOptions): WozDisk {
         debug('Invalid woz header');
     }
 
-    debug(chunks);
+    // debug(chunks);
 
-    const { meta, tmap, trks } = chunks;
+    const { meta, tmap, trks, info } = chunks;
 
     const disk: WozDisk = {
         encoding: ENCODING_BITSTREAM,
@@ -296,6 +299,7 @@ export default function createDiskFromWoz(options: DiskOptions): WozDisk {
         readOnly: true, //chunks.info.writeProtected === 1;
         name: meta?.values['title'] || options.name,
         side: meta?.values['side_name'] || meta?.values['side'],
+        info
     };
 
     return disk;

test/js/cards/disk2.spec.ts

@@ -1,7 +1,10 @@
 /** @jest-environment jsdom */
+import fs from 'fs';
+
 import Apple2IO from 'js/apple2io';
 import DiskII, { Callbacks } from 'js/cards/disk2';
 import CPU6502 from 'js/cpu6502';
+import { byte } from 'js/types';
 import { VideoModes } from 'js/videomodes';
 import { mocked } from 'ts-jest/utils';
 import { BYTES_BY_SECTOR_IMAGE, BYTES_BY_TRACK_IMAGE } from '../formats/testdata/16sector';
@@ -248,6 +251,7 @@ describe('DiskII', () => {
             diskII.ioSwitch(0x83);  // coil 1 on
             diskII.ioSwitch(0x80);  // coil 0 off
             diskII.ioSwitch(0x85);  // coil 2 on
+            diskII.ioSwitch(0x82);  // coil 1 off
             diskII.ioSwitch(0x87);  // coil 3 on
             diskII.ioSwitch(0x84);  // coil 2 off
             diskII.ioSwitch(0x81);  // coil 0 on
@@ -499,5 +503,196 @@ describe('DiskII', () => {
             expect(track0[0]).toBe(0x80);
             expect(track0[1]).toBe(0x81);
         });
+
+        it('sets disk state to dirty and calls the dirty callback when written', () => {
+            const diskII = new DiskII(mockApple2IO, callbacks);
+            diskII.setBinary(1, 'BYTES_BY_TRACK', 'po', BYTES_BY_TRACK_IMAGE);
+            let state = diskII.getState();
+            state.drives[0].dirty = false;
+            diskII.setState(state);
+            jest.resetAllMocks();
+
+            diskII.ioSwitch(0x89);        // turn on the motor
+            diskII.ioSwitch(0x8F, 0x80);  // write
+            diskII.ioSwitch(0x8C);        // shift
+
+            expect(callbacks.dirty).toHaveBeenCalledTimes(1);
+            expect(callbacks.dirty).toHaveBeenCalledWith(1, true);
+
+            state = diskII.getState();
+            expect(state.drives[0].dirty).toBeTruthy();
+        });
+    });
+
+    describe('reading WOZ-based disks', () => {
+        const DOS33_SYSTEM_MASTER_IMAGE =
+            fs.readFileSync('test/js/cards/data/DOS 3.3 System Master.woz').buffer;
+
+        it('accepts WOZ-based disks', () => {
+            const diskII = new DiskII(mockApple2IO, callbacks);
+            diskII.setBinary(1, 'DOS 3.3 System Master', 'woz', DOS33_SYSTEM_MASTER_IMAGE);
+
+            expect(true).toBeTruthy();
+        });
+
+        it('stops the head at the end of the image', () => {
+            const diskII = new DiskII(mockApple2IO, callbacks);
+            diskII.setBinary(1, 'DOS 3.3 System Master', 'woz', DOS33_SYSTEM_MASTER_IMAGE);
+            setTrack(diskII, 33);
+
+            diskII.ioSwitch(0x89);  // turn on the motor
+            diskII.ioSwitch(0x85);  // coil 2 on
+            for (let i = 0; i < 5; i++) {
+                diskII.ioSwitch(0x87);  // coil 3 on
+                diskII.ioSwitch(0x84);  // coil 2 off
+                diskII.ioSwitch(0x81);  // coil 0 on
+                diskII.ioSwitch(0x86);  // coil 3 off
+                diskII.ioSwitch(0x83);  // coil 1 on
+                diskII.ioSwitch(0x80);  // coil 0 off
+                diskII.ioSwitch(0x85);  // coil 2 on
+                diskII.ioSwitch(0x82);  // coil 1 off
+            }
+            diskII.ioSwitch(0x84);  // coil 2 off
+
+            const state = diskII.getState();
+            expect(state.drives[0].phase).toBe(2);
+            // For WOZ images, the number of tracks is the number in the image.
+            // The DOS3.3 System Master was imaged on a 40 track drive, so it
+            // has data for all 40 tracks, even though the last few are garbage.
+            expect(state.drives[0].track).toBe(40 * STEPS_PER_TRACK - 1);
+        });
+
+        it('spins the disk when motor is on', () => {
+            let cycles: number = 0;
+            mocked(mockApple2IO).cycles.mockImplementation(() => cycles);
+
+            const diskII = new DiskII(mockApple2IO, callbacks);
+            diskII.setBinary(1, 'DOS 3.3 System Master', 'woz', DOS33_SYSTEM_MASTER_IMAGE);
+
+            let state = diskII.getState();
+            expect(state.drives[0].head).toBe(0);
+
+            diskII.ioSwitch(0x89);  // turn on the motor
+            cycles += 10;
+            diskII.tick();
+
+            state = diskII.getState();
+            expect(state.drives[0].head).toBeGreaterThan(0);
+        });
+
+        it('does not spin the disk when motor is off', () => {
+            let cycles: number = 0;
+            mocked(mockApple2IO).cycles.mockImplementation(() => cycles);
+
+            const diskII = new DiskII(mockApple2IO, callbacks);
+            diskII.setBinary(1, 'DOS 3.3 System Master', 'woz', DOS33_SYSTEM_MASTER_IMAGE);
+
+            let state = diskII.getState();
+            expect(state.drives[0].head).toBe(0);
+
+            cycles += 10;
+            diskII.tick();
+
+            state = diskII.getState();
+            expect(state.drives[0].head).toBe(0);
+        });
+
+        it('reads an FF sync byte from the beginning of the image', () => {
+            let cycles: number = 0;
+            mocked(mockApple2IO).cycles.mockImplementation(() => cycles);
+
+            const diskII = new DiskII(mockApple2IO, callbacks);
+            diskII.setBinary(1, 'DOS 3.3 System Master', 'woz', DOS33_SYSTEM_MASTER_IMAGE);
+
+            diskII.ioSwitch(0x89);  // turn on the motor
+            diskII.ioSwitch(0x8e);  // read mode
+
+            // The initial bytes in the image are: FF 3F CF F3
+            // making the bit stream:
+            //
+            //     1111 1111 0011 1111 1100 1111 1111 0011
+            //
+            // That's three FF sync bytes in a row. Assuming
+            // the sequencer is in state 2, each sync byte takes
+            // 32 clock cycles to read, is held for 8 clock
+            // cycles while the extra zeros are shifted in, then
+            // is held 8 more clock cycles while the sequencer
+            // reads the next two bits.
+            cycles += 40;  // shift 10 bits
+            const nibble = diskII.ioSwitch(0x8c);  // read data
+            expect(nibble).toBe(0xFF);
+        });
+
+        it('reads several FF sync bytes', () => {
+            let cycles: number = 0;
+            mocked(mockApple2IO).cycles.mockImplementation(() => cycles);
+
+            const diskII = new DiskII(mockApple2IO, callbacks);
+            diskII.setBinary(1, 'DOS 3.3 System Master', 'woz', DOS33_SYSTEM_MASTER_IMAGE);
+
+            diskII.ioSwitch(0x89);  // turn on the motor
+            diskII.ioSwitch(0x8e);  // read mode
+
+            // The initial bytes in the image are: FF 3F CF F3
+            // making the bit stream:
+            //
+            //     1111 1111 0011 1111 1100 1111 1111 0011
+            //
+            // That's three FF sync bytes in a row. Assuming
+            // the sequencer is in state 2, each sync byte takes
+            // 32 clock cycles to read, is held for 8 clock
+            // cycles while the extra zeros are shifted in, then
+            // is held 8 more clock cycles while the sequencer
+            // reads the next two bits.  This means that 3 sync
+            // bytes will be available for 3 * 40 + 8 cycles.
+            for (let i = 0; i < 3 * 40 + 8; i++) {
+                cycles++;
+                const nibble = diskII.ioSwitch(0x8c);  // read data
+                if (nibble & 0x80) {
+                    // Nibbles are only valid when the high bit is set.
+                    // eslint-disable-next-line jest/no-conditional-expect
+                    expect(nibble).toBe(0xFF);
+                }
+            }
+        });
+
+        it('reads random garbage on uninitialized tracks', () => {
+            let cycles: number = 0;
+            mocked(mockApple2IO).cycles.mockImplementation(() => cycles);
+
+            const diskII = new DiskII(mockApple2IO, callbacks);
+            diskII.setBinary(1, 'DOS 3.3 System Master', 'woz', DOS33_SYSTEM_MASTER_IMAGE);
+
+            // Step to track 0.5
+            diskII.ioSwitch(0x89);  // turn on the motor
+            diskII.ioSwitch(0x81);  // coil 0 on
+            diskII.ioSwitch(0x83);  // coil 1 on
+            diskII.ioSwitch(0x80);  // coil 0 off
+            diskII.ioSwitch(0x82);  // coil 1 off
+            diskII.ioSwitch(0x8e);  // read mode
+
+            // Read 5 nibbles
+            const nibbles: byte[] = [];
+            let read = false;
+            while (nibbles.length < 5) {
+                cycles++;
+                const nibble = diskII.ioSwitch(0x8c);  // read data
+                const qa = nibble & 0x80;
+                if (qa && !read) {
+                    nibbles.push(nibble);
+                    read = true;
+                }
+                if (!qa && read) {
+                    read = false;
+                }
+            }
+            // Test that the first doesn't equal any of the others.
+            // (Yes, this test could fail with some bad luck.)
+            let equal = false;
+            for (let i = 1; i < 5; i++) {
+                equal ||= nibbles[0] === nibbles[i];
+            }
+            expect(equal).not.toBeTruthy();
+        });
     });
 });

test/js/formats/woz.spec.ts

@@ -19,7 +19,7 @@ describe('woz', () => {
             rawData: mockWoz1
         };
 
-        const disk = createDiskFromWoz(options) ;
+        const disk = createDiskFromWoz(options);
         expect(disk).toEqual({
             name: 'Mock Woz 1',
             readOnly: true,
@@ -31,9 +31,7 @@ describe('woz', () => {
                 1, 0, 0, 1, 0, 1, 1, 0,
             ])],
             tracks: [new Uint8Array([0xD5, 0xAA, 0x96])],
-        });
-        expect(console.log).toHaveBeenCalledWith(expect.objectContaining({
-            info:  {
+            info: {
                 bitTiming: 0,
                 bootSector: 0,
                 cleaned: 0,
@@ -47,7 +45,7 @@ describe('woz', () => {
                 version: 1,
                 writeProtected: 0
             }
-        }));
+        });
     });
 
     it('can parse Woz version 2', () => {
@@ -58,7 +56,7 @@ describe('woz', () => {
             rawData: mockWoz2
         };
 
-        const disk = createDiskFromWoz(options) ;
+        const disk = createDiskFromWoz(options);
         expect(disk).toEqual({
             name: 'Mock Woz 2',
             side: 'B',
@@ -71,9 +69,7 @@ describe('woz', () => {
                 1, 0, 0, 1, 0, 1, 1, 0,
             ])],
             tracks: [new Uint8Array([0xD5, 0xAA, 0x96])],
-        });
-        expect(console.log).toHaveBeenCalledWith(expect.objectContaining({
-            info:  {
+            info: {
                 bitTiming: 0,
                 bootSector: 0,
                 cleaned: 0,
@@ -87,6 +83,6 @@ describe('woz', () => {
                 version: 2,
                 writeProtected: 0
             }
-        }));
+        });
     });
 });