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Documentation Index

Fetch the complete documentation index at: https://mintlify.com/mihaip/infinite-mac/llms.txt

Use this file to discover all available pages before exploring further.

The embedded Infinite Mac emulator supports two-way communication with the parent page through the browser’s standard window.postMessage API. You can send control commands to the emulator (pause, keyboard/mouse input, disk loading) and listen for status notifications (boot complete, screen updates). The full TypeScript definitions for both directions live in src/embed-types.ts.

​
Basic Send / Receive Pattern

// Get a reference to the iframe
const iframe = document.getElementById("my-mac");

// Send a command TO the emulator
iframe.contentWindow.postMessage({ type: "emulator_pause" }, "*");

// Receive notifications FROM the emulator
window.addEventListener("message", (event) => {
  switch (event.data.type) {
    case "emulator_loaded":
      console.log("Mac has finished booting!");
      break;
    case "emulator_screen":
      const { data, width, height } = event.data;
      console.log(`Screen frame: ${width}×${height}`);
      break;
  }
});

​
Sending Messages — EmbedControlEvent

​
emulator_pause

Pause the emulator. Useful for reducing CPU and GPU usage when the user is not actively interacting with the embed. See also the paused and auto_pause URL parameters for automatic pause behaviour. 
{ type: "emulator_pause" }

iframe.contentWindow.postMessage({ type: "emulator_pause" }, "*");

​
emulator_unpause

Resume a paused emulator. 
{ type: "emulator_unpause" }

iframe.contentWindow.postMessage({ type: "emulator_unpause" }, "*");

​
emulator_mouse_move

Send a mouse movement event. The coordinate semantics depend on the underlying emulator:
  • Absolute coordinates (x, y) — supported by Mini vMac, Basilisk II, SheepShaver, and Snow.
  • Relative coordinates (deltaX, deltaY) — used by Previous, DingusPPC, and PearPC.
You should always supply all four fields; each emulator will read the ones it supports. 
{
  type: "emulator_mouse_move";
  x: number;       // absolute X position
  y: number;       // absolute Y position
  deltaX: number;  // relative X delta
  deltaY: number;  // relative Y delta
}

// Move to absolute position (320, 240) / relative (+2, +4)
iframe.contentWindow.postMessage(
  { type: "emulator_mouse_move", x: 320, y: 240, deltaX: 2, deltaY: 4 },
  "*"
);

​
emulator_mouse_down / emulator_mouse_up

Send a mouse button press or release. button follows the same numbering as MouseEvent.button: 0 = left, 1 = middle, 2 = right. Right-click (button: 2) is only supported by certain emulator and OS combinations — specifically Previous, and DingusPPC running Mac OS X. 
{
  type: "emulator_mouse_down" | "emulator_mouse_up";
  button: number;  // 0 = left, 1 = middle, 2 = right
}

// Left click
iframe.contentWindow.postMessage({ type: "emulator_mouse_down", button: 0 }, "*");
iframe.contentWindow.postMessage({ type: "emulator_mouse_up",   button: 0 }, "*");

// Right click (Previous / DingusPPC + Mac OS X only)
iframe.contentWindow.postMessage({ type: "emulator_mouse_down", button: 2 }, "*");
iframe.contentWindow.postMessage({ type: "emulator_mouse_up",   button: 2 }, "*");

​
emulator_key_down / emulator_key_up

Send a physical key press or release. The code property uses the same values as the KeyboardEvent.code property — for example "KeyA", "ArrowLeft", "MetaLeft", "Enter". 
{
  type: "emulator_key_down" | "emulator_key_up";
  code: string;  // KeyboardEvent.code value
}

// Type the letter "A"
iframe.contentWindow.postMessage({ type: "emulator_key_down", code: "KeyA" }, "*");
iframe.contentWindow.postMessage({ type: "emulator_key_up",   code: "KeyA" }, "*");
See src/emulator/common/key-codes.ts for the full list of key codes recognised by the emulator.

​
emulator_load_disk

Load a disk image from a URL into the running emulator. The url must point to an uncompressed disk image file (.dsk, .img, .iso, .toast, etc.). Supported emulators: Mini vMac, Basilisk II, SheepShaver, Previous, and Snow (machines with a SCSI bus). Not supported by DingusPPC or PearPC. 
{
  type: "emulator_load_disk";
  url: string;  // URL to an uncompressed disk image
}

iframe.contentWindow.postMessage(
  { type: "emulator_load_disk", url: "https://example.com/my-app.dsk" },
  "*"
);

​
Receiving Messages — EmbedNotificationEvent

​
emulator_loaded

Fired once when the emulator has finished loading all of its data files and the emulated machine has begun running. This is the earliest point at which it is safe to send input events. 
{ type: "emulator_loaded" }

window.addEventListener("message", (event) => {
  if (event.data.type === "emulator_loaded") {
    console.log("Emulator is ready.");
  }
});

​
emulator_screen

Fired on every frame when the screen contents change. The data field is a Uint8ClampedArray containing raw pixel data in RGBA format (4 bytes per pixel, row-major order). width and height give the dimensions of the frame. 
{
  type: "emulator_screen";
  data: Uint8ClampedArray;
  width: number;
  height: number;
}

window.addEventListener("message", (event) => {
  if (event.data.type === "emulator_screen") {
    const { data, width, height } = event.data;
    // e.g. paint onto a canvas
    const imageData = new ImageData(data, width, height);
    ctx.putImageData(imageData, 0, 0);
  }
});
emulator_screen events are only emitted when the screen_update_messages=true URL parameter is set on the embed URL. Without it, no screen frames are sent to the parent page.

​
Complete Working Example

The page below embeds a System 7.1 Quadra 650, logs a message when the machine finishes booting, and automatically pauses the emulator after 5 seconds. 
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8" />
  <title>Infinite Mac postMessage Demo</title>
</head>
<body>
  <iframe
    id="my-mac"
    src="https://infinitemac.org/embed?disk=System+7.1&machine=Quadra+650&screenSize=640x480"
    width="640"
    height="480"
    allow="cross-origin-isolated"
    frameborder="0">
  </iframe>

  <script>
    const iframe = document.getElementById("my-mac");

    // 1. Listen for notifications from the emulator
    window.addEventListener("message", (event) => {
      switch (event.data.type) {
        case "emulator_loaded":
          console.log("Mac has finished booting and is now running.");
          break;
      }
    });

    // 2. Pause the emulator after 5 seconds
    setTimeout(() => {
      console.log("Sending pause command…");
      iframe.contentWindow.postMessage({ type: "emulator_pause" }, "*");
    }, 5000);
  </script>
</body>
</html>
1

Create the iframe

Point the src at the /embed endpoint with your chosen disk, machine, and screen size parameters.
2

Listen for emulator_loaded

Attach a message listener on window and branch on event.data.type. Wait for emulator_loaded before sending any input commands.
3

Send control messages

Use iframe.contentWindow.postMessage(payload, "*") to send any of the EmbedControlEvent payloads documented above.

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