# ZiPad

> ZiPad turns older and idle iPads (such as iPad Air 1, iPad mini 2/3/4, running iOS 12.0+) into ultra-low-latency 60 FPS secondary displays and Apple Pencil drawing tablets for Mac. It serves as a high-performance, lightweight, and hardware-accelerated alternative to Apple Sidecar and Duet Display.

Official Website: https://zipad.meluon.fun/
Developer: meluon (https://github.com/meluon)

## Overview & Key Advantages

- **Legacy Device Compatibility**: Full support for iOS 12.0+ legacy hardware powered by Apple A7, A8, A9, and A10 processors (e.g. iPad Air 1, iPad mini 2, iPad mini 3, iPad mini 4) which are officially unsupported by Apple Sidecar.
- **Ultra-Low Latency (~16ms)**: Custom C99 zero-copy wire protocol (`ZPProtocol`) streaming H.264 over native `usbmuxd` USB tunnels.
- **Hardware Native VideoToolbox Decoding**: Hardware accelerated decoding on the iPad's A-series GPU/VPU with zero texture copies (`AVSampleBufferDisplayLayer`), keeping CPU utilization below 3% and avoiding overheating.
- **Seamless Roaming**: Seamless zero-flicker transition between USB high-speed tethering and local Wi-Fi / AWDL wireless connections.
- **100% Offline & Private**: Zero cloud dependencies, zero external analytics, and zero telemetry. Ed25519 asymmetric cryptographic license validation.
- **Pricing & Value**: Free 30-minute renewable sessions. One-time lifetime license at ¥59 CNY ($14.99 USD), replacing costly ¥280/year subscriptions (Duet Display) or ¥1,299 portable external monitors.

## Target Hardware & Requirements

- **Mac Host**: macOS 12.0 (Monterey) or later (Apple Silicon M1-M4 & Intel Macs).
- **iPad Client**: iOS 12.0 through iOS 18+ (tested on iPad Air 1, iPad mini 2/3/4, iPad 5th/6th Gen, iPad Pro).
- **Connection**: USB-A/C to Lightning cable (preferred for 16ms wired mode) or local Wi-Fi (5GHz recommended).

## Fast Installation

- **macOS Quick Install via Terminal**:
  ```bash
  curl -fsSL https://zipad.meluon.fun/install.sh | bash
  ```
- **Direct macOS DMG Download**:
  `https://zipad.meluon.fun/download/ZiPad-Host.dmg`
- **iPad IPA Package**:
  `https://zipad.meluon.fun/download/ZiPadDisplay.ipa` (Sideloadable via Sideloadly, AltStore, TrollStore, or AppSync Unified)

## Documentation & Deep Dive

- [Full Specifications and Technical Details](https://zipad.meluon.fun/llms-full.txt): Complete protocol documentation, FAQ, benchmark numbers, and architectural overview.