--- a/runtime/audio.js	2026-10-13 10:36:31.489048874 +0000
+++ b/runtime/audio.js	2026-10-13 10:36:31.492051502 +0000
@@ -26,7 +26,7 @@
         this.readPtr = 0;
         this.writePtr = 0;
 
-        this.scriptNode = this.audioContext.createScriptProcessor(0, 0, 2);
+        this.scriptNode = this.audioContext.createScriptProcessor(2048, 0, 2);
         this.scriptNode.onaudioprocess = (audioProcessingEvent) => {
             const outputBuffer = audioProcessingEvent.outputBuffer;
             const leftData = outputBuffer.getChannelData(0);
@@ -34,6 +34,15 @@
 
             let availableDataLength = this.writePtr - this.readPtr;
             if (availableDataLength < 0) availableDataLength += BUFFER_SIZE;
+            // jacar.es: never let the sound fall behind the picture. Samples pile
+            // up whenever frames are produced while the context is not playing
+            // them (started suspended, a stalled tab), and this loop only ever
+            // reads one buffer at a time, so the lag would stay for good: skip
+            // ahead to a small, fixed backlog instead.
+            if (availableDataLength > 2 * leftData.length + 2 * this.samplesPerFrame) {
+                this.readPtr = (this.writePtr - leftData.length - this.samplesPerFrame + BUFFER_SIZE) % BUFFER_SIZE;
+                availableDataLength = leftData.length + this.samplesPerFrame;
+            }
 
             if (availableDataLength >= leftData.length) {
                 // enough data is available to fill the buffer
--- a/runtime/jsspeccy.js	2026-10-13 10:36:31.489145458 +0000
+++ b/runtime/jsspeccy.js	2026-10-13 10:36:31.492103710 +0000
@@ -24,7 +24,7 @@
     constructor(canvas, opts) {
         super();
         this.canvas = canvas;
-        this.worker = new Worker(new URL('jsspeccy-worker.js', scriptUrl));
+        this.worker = new Worker(new URL('jsspeccy-worker.js' + new URL(scriptUrl).search, scriptUrl))  /* jacar.es: the page's version query, so a new worker is never served from cache */;
         this.keyboardEnabled = ('keyboardEnabled' in opts) ? opts.keyboardEnabled : true;
         if (this.keyboardEnabled) {
             this.keyboardHandler = (opts.keyboardMap == 'recreated')
@@ -392,6 +392,11 @@
             message: 'stopTape',
         });
     }
+    pokeMemory(pokes) {
+        this.worker.postMessage({
+            message: 'poke', pokes,
+        });
+    }
 
     exit() {
         this.pause();
@@ -727,5 +732,14 @@
             }
         },
         exit: () => {exit();},
+        // jacar.es: the tape transport, so a page can drive it from its own
+        // cassette deck (and follow it: 'playingTape' / 'stoppedTape')
+        playTape: () => {emu.playTape();},
+        stopTape: () => {emu.stopTape();},
+        isTapePlaying: () => emu.tapeIsPlaying,
+        setAutoLoadTapes: (val) => {emu.setAutoLoadTapes(val);},
+        reset: () => {emu.reset();},
+        poke: (pokes) => {emu.pokeMemory(pokes);},
+        on: (event, handler) => {emu.on(event, handler);},
     };
 };
--- a/runtime/worker.js	2026-10-13 10:36:31.489196249 +0000
+++ b/runtime/worker.js	2026-10-13 10:36:38.878030684 +0000
@@ -13,8 +13,13 @@
 let tapeIsPlaying = false;
 
 const loadCore = (baseUrl) => {
-    WebAssembly.instantiateStreaming(
-        fetch(new URL('jsspeccy-core.wasm', baseUrl), {})
+    // jacar.es: compile from the bytes, not the stream: instantiateStreaming
+    // insists on the application/wasm MIME type, and a server that sends .wasm
+    // as application/octet-stream left the emulator without its core.
+    fetch(new URL('jsspeccy-core.wasm', baseUrl)).then(
+        r => r.arrayBuffer()
+    ).then(
+        bytes => WebAssembly.instantiate(bytes, {})
     ).then(results => {
         core = results.instance.exports;
         memory = core.memory;
@@ -250,6 +255,10 @@
         case 'setTapeTraps':
             core.setTapeTraps(e.data.value);
             break;
+        case 'poke':
+            // jacar.es: write bytes into the running machine's memory (POKEs)
+            for (const [addr, val] of e.data.pokes) core.poke(addr, val);
+            break;
         default:
             console.log('message received by worker:', e.data);
     }