A native macOS companion app for your Commodore 64 Ultimate device — browse and manage files, write BASIC programs, view a live CRT display, and control your device from your Mac.
More screenshots: File manager · BASIC Scratchpad
Demo Video (Recorded for App Review): https://youtu.be/_2wJO2wOGm8
Features
- Two connection modes — Viewer Mode passively listens for streams; Toolbox Mode connects via REST API and FTP for full device control
- File manager — Browse, upload, download, rename, and delete files on your device. Create D64, D71, D81, and DNP disk images. Mount and unmount drives. Drag and drop from Finder.
- BASIC scratchpad — Write Commodore BASIC programs on your Mac and send them directly to your C64U. Includes sample programs to get started.
- Remote debug monitor — Interactive monitor for reading/writing memory and inspecting machine state
- Live video and audio — Real-time UDP video and audio streaming with audio balance control
- CRT shader effects — Metal-based post-processing with scanlines, bloom, phosphor afterglow, shadow masks, barrel distortion, and vignette
- 8 built-in presets — Clean, Home CRT, P3 Amber, P1 Green, Crisp, Warm Glow, Old TV, Arcade
- Custom presets — Save, modify, and delete your own CRT configurations
- Device control — Start/stop streams, load SID/MOD/PRG/CRT files, mount disk images, reset/reboot/power off, pause/resume, access the Ultimate menu
- Keyboard forwarding — Type on your Mac keyboard and have it appear on the C64, with an on-screen strip for C64-specific keys
- Auto device discovery — Automatically scans your network to find Ultimate devices with service status and password indicators
- Screenshot and video recording — Capture the CRT-processed output with synchronized audio
- Password support — Connect to password-protected devices with saved credentials
- Zero dependencies — Pure Apple frameworks (Metal, Network, AVFoundation, AppKit)
Requirements
- macOS 26 or later
- Xcode 26 (to build from source)
- A Commodore 64 Ultimate device on the local network
- Toolbox Mode requires FTP File Service and Web Remote Control Service enabled on the device
Download
- Download C64 Ultimate Toolbox v2.0 for macOS 26 and later
- Or, Purchase C64 Ultimate Toolbox on the App Store for automatic updates.
Download (For Older Macs)
Building
Open C64 Ultimate Toolbox.xcodeproj in Xcode and build. No package dependencies to resolve.
Usage
How It Works
The app communicates with the C64U over multiple channels:
- HTTP REST API — Device info, stream control, file loading, machine control, keyboard injection (Toolbox Mode)
- FTP — File browsing, upload, download, and management (Toolbox Mode)
- UDP port 11000 — Video stream (4-bit indexed color, converted to RGBA)
- UDP port 11001 — Audio stream (16-bit stereo PCM at ~48kHz)
Video frames are assembled from UDP packets, converted from the C64's 4-bit palette to RGBA, then rendered through a Metal CRT shader pipeline at the window's native resolution.