Writing implemented, but not working yet

Author: mattgodbolt

.vscode/settings.json

@@ -1,6 +1,6 @@
 {
-    "editor.defaultFormatter": "esbenp.prettier-vscode",
-    "[javascript]": {
-      "editor.defaultFormatter": "esbenp.prettier-vscode"
-    }
-  }
+  "editor.defaultFormatter": "esbenp.prettier-vscode",
+  "[javascript]": {
+    "editor.defaultFormatter": "esbenp.prettier-vscode"
+  }
+}

6502.js

@@ -1158,7 +1158,7 @@ export class Cpu6502 extends Base6502 {
             this.acia = new Acia(this, this.soundChip.toneGenerator, this.scheduler, this.touchScreen);
             this.serial = new Serial(this.acia);
             this.ddNoise.spinDown();
-            this.fdc = new this.model.Fdc(this, this.scheduler);
+            this.fdc = new this.model.Fdc(this, this.ddNoise, this.scheduler);
             this.crtc = this.video.crtc;
             this.ula = this.video.ula;
             this.adconverter = new Adc(this.sysvia, this.scheduler);

disc-drive.js

@@ -105,10 +105,7 @@ export class DiscDrive {
             this._headPosition = 0;
             this._checkTrackNeedsWrite();
         }
-        // Forcibly reschedule. Some of the callbacks may "stopSpinning/startSpinning" and thus
-        // rescheduled this callback already, but we want to override that.
-        this._timer.reschedule(nextTicks - thisTicks);
-        this._spinning = true;
+        if (this._spinning) this._timer.reschedule(nextTicks - thisTicks);
     }
 
     get headPosition() {
@@ -142,7 +139,7 @@ export class DiscDrive {
     get spinning() {
         // beebjit uses the timer's scheduledness here, but our schedule system deschedules timers
         // during callbacks, which makes this briefly "false" and disturbs things.
-        return this._spinning || this._timer.scheduled();
+        return this._spinning;
     }
 
     startSpinning() {
@@ -177,7 +174,16 @@ export class DiscDrive {
     }
 
     writePulses(pulses) {
-        throw new Error(`Not supported: ${pulses}`);
+        if (!this.disc) return;
+        // All drives seen have a write protect failsafe on the drive itself.
+        if (this.disc.writeProtected) return;
+        if (this._in32usMode) {
+            if (pulses & 0xffff0000) throw new Error(`Unable to write 32us pulses for ${pulses}`);
+            const existingPulses = this.disc.readPulses(this._isSideUpper, this.track, this.headPosition);
+            if (this._pulsePosition === 0) pulses = (existingPulses & 0x0000ffff) | (pulses << 16);
+            else pulses = (existingPulses & 0xffff0000) | pulses;
+        }
+        this.disc.writePulses(this._isSideUpper, this.track, this.headPosition, pulses);
     }
 
     get writeProtect() {

disc.js

@@ -272,9 +272,9 @@ export class Disc {
         return new Disc(true, true, new DiscConfig());
     }
     /**
-     * @param {boolean} isWriteable 
-     * @param {boolean} isMutable 
-     * @param {DiscConfig} config 
+     * @param {boolean} isWriteable
+     * @param {boolean} isMutable
+     * @param {DiscConfig} config
      */
     constructor(isWriteable, isMutable, config) {
         this.config = config;
@@ -302,7 +302,11 @@ export class Disc {
         this.load();
     }
 
-    /// @returns {Track}
+    get writeProtected() {
+        return !this.isWriteable;
+    }
+
+    /** @returns {Track} */
     getTrack(isSideUpper, trackNum) {
         return isSideUpper ? this.upperSide.tracks[trackNum] : this.lowerSide.tracks[trackNum];
     }
@@ -334,6 +338,26 @@ export class Disc {
         return this.getTrack(isSideUpper, track).pulses2Us[position];
     }
 
+    /**
+     * @param {boolean} isSideUpper
+     * @param {Number} track
+     * @param {Number} position
+     * @param {Number} pulses
+     */
+    writePulses(isSideUpper, track, position, pulses) {
+        const trackObj = this.getTrack(isSideUpper, track);
+        if (position >= trackObj.length)
+            throw new Error(`Attempt to write off end of track ${position} > ${track.length}`);
+        if (this.isDirty) {
+            if (isSideUpper !== this.dirtySide || track !== this.dirtyTrack)
+                throw new Error("Switched dirty track or side");
+        }
+        this.isDirty = true;
+        this.dirtySide = isSideUpper;
+        this.dirtyTrack = track;
+        trackObj.pulses2Us[position] = pulses;
+    }
+
     flushWrites() {
         if (!this.isDirty) {
             if (this.dirtySide !== -1 || this.dirtyTrack !== -1) throw new Error("Bad state in disc dirty tracking");

fdc.js

@@ -32,29 +32,30 @@ export function emptySsd(fdc) {
 
 export function discFor(fdc, name, stringData, onChange) {
     const data = typeof stringData !== "string" ? stringData : utils.stringToUint8Array(stringData);
-    // const prevData = new Uint8Array(data);
-
-    //// HACKY MCHACKFACE
-    const disc = new Disc(false, false, new DiscConfig());
-    return loadSsd(disc, data, false);
-
-    // function changed() {
-    //     let res = false;
-    //     for (let i = 0; i < data.length; ++i) {
-    //         if (data[i] !== prevData[i]) {
-    //             prevData[i] = data[i];
-    //             res = true;
-    //         }
-    //     }
-    //     return res;
-    // }
-
-    // return new BaseDisc(fdc, name, data, (disc) => {
-    //     if (!changed()) return;
-    //     if (onChange) {
-    //         onChange(disc.data);
-    //     }
-    // });
+    const prevData = new Uint8Array(data);
+
+    if (fdc.isPulseLevel) {
+        //// TODO: handle onChange
+        const disc = new Disc(false, false, new DiscConfig());
+        return loadSsd(disc, data, false);
+    }
+    function changed() {
+        let res = false;
+        for (let i = 0; i < data.length; ++i) {
+            if (data[i] !== prevData[i]) {
+                prevData[i] = data[i];
+                res = true;
+            }
+        }
+        return res;
+    }
+
+    return new BaseDisc(fdc, name, data, (disc) => {
+        if (!changed()) return;
+        if (onChange) {
+            onChange(disc.data);
+        }
+    });
 }
 
 export function localDisc(fdc, name) {