Purple Computer

Give them a first computer you can feel good about.

Transform your old laptop into a calm space for open-ended play. No internet, no apps. Designed for 4–7 and fun for 2–8+. They explore, create, and put it down on their own.

🚧 WORK IN PROGRESS Purple Computer is still in active development and testing. The installer ISO is not ready for use yet. We'll announce when it's ready.

Purple Computer is a paid product. The source code is public so you can see how it works, but Purple Computer is not free software. To use it, purchase at purplecomputer.org or contact us at tavi@purplecomputer.org.

You're welcome to look around and try things out. See LICENSE for details.

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What Is Purple?

Purple Computer turns your old laptop into a calm, creative computer for kids. When you turn it on, it starts straight into Purple. There's no desktop and no other apps.

• Building, not consuming. Words, colors, sounds, and numbers to play with.
• Nothing to break. The whole laptop is Purple. No apps, no internet, nothing to mess up.
• A screen they walk away from. No tantrums, no parental controls needed.
• Pay once, use on every laptop. Works on every laptop you own, now or later.

Learn more at purplecomputer.org.

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Quick Start

For Development (Linux only)

Purple Computer requires Linux with evdev for keyboard input. macOS is not supported. Use a Linux VM if developing on Mac (see guides/linux-vm-dev-setup.md).

git clone https://github.com/purplecomputerorg/purplecomputer.git
cd purplecomputer
make setup    # Creates venv, installs deps, downloads TTS voice, installs fonts
make run      # Launches in Alacritty with Purple theme

Inside Purple Computer, try:

2 + 2                  # Math with dot visualization
3 * 4 + 2              # Operator precedence (= 14)
cat * 5                # Five cats
dog + cat              # Emoji addition (🐶 🐱)
3 + 4 + 2 bananas      # Numbers attach to emoji (= 9 bananas)
red + blue             # Color mixing (= purple)
purple truck           # Color swatch + emoji in free text
I love cat!            # Speaks "I love cat" aloud (! triggers speech)

For Installation (Old Laptop)

Build and test installer:

cd build-scripts

# Build everything (20-35 min first time, 15-25 min subsequent)
./build-in-docker.sh

# Validate build (checks configs, verifies artifacts)
./validate-build.sh

# Result: /opt/purple-installer/output/purple-installer-YYYYMMDD.iso

Flash to USB:

# List USB drives and find your drive's serial number
./build-scripts/flash-to-usb.sh --list

# Add your drive's serial to the whitelist (one-time setup)
echo 'YOUR_DRIVE_SERIAL' >> .flash-drives.conf

# Flash the latest ISO (with verification)
./build-scripts/flash-to-usb.sh

Install to hardware:

1. Boot laptop from USB (Secure Boot can remain enabled)
2. Installation runs automatically (10-20 minutes)
3. System reboots into Purple Computer

The system logs in automatically as the purple user (no password needed).

See MANUAL.md for complete build/customization details.

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The Three Rooms

Purple has three rooms:

Key	Room	What It Does
F1	Play	Type a word, see an emoji, hear it spoken, mix colors, do math. Kids who can read get the most out of this, but even pre-readers can use it with just numbers (2 + 3). See guides/play-room-design.md
F2	Music	Make music and draw with the keyboard. Press any key to play a sound and paint a color. Even a 2-year-old can have fun here.
F3	Art	Write and paint with colors that mix like real paint. Great around 3-4+.

Controls:

• Escape (tap): Room picker (Play, Music, Art)
• F1-F3: Switch rooms directly
• F9: Toggle dark/light theme
• F10: Mute/unmute, F11: Volume down, F12: Volume up
• Caps Lock: Toggle big/small letters
• Ctrl+V: Cycle views (Screen → Line → Ears)
• Tab (in Art): Toggle write/paint mode
• Hold Escape (1s): Parent mode (admin menu)

Speech (in Play room): Add ! anywhere (e.g., cat!) or use say/talk prefix to hear results spoken aloud.

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Keyboard Features

Purple includes a hardware keyboard normalizer that makes typing easier for kids:

Easy Capitals (No Shift Key Needed)

• Double-tap any key — Types the shifted version (a a → A, 1 1 → !)
• Tap Shift quickly — Activates "sticky shift" for the next character
• Hold Shift + type — Normal shift behavior (uppercase while held)

Kids can type capital letters without holding two keys at once!

Parent Mode

• Hold Escape for 1 second — Opens parent menu (display settings, volume, updates)

F-Key Setup

On first boot, Purple automatically runs keyboard setup. You'll be asked to press F1 through F12. This captures each key's scancode, making F-keys work regardless of the laptop's default behavior (some laptops send brightness/volume instead of F1-F12).

How It Works

Purple Computer requires Linux with evdev. macOS is not supported.

Keyboard input is read directly from evdev, bypassing the terminal. The terminal (Alacritty) is display-only. This gives us:

• True key down/up events for reliable timing
• Space-hold detection for paint mode
• All keycodes (terminals drop some F-keys)

The keyboard handling:

• Grabs the hardware keyboard exclusively (kiosk mode)
• Remaps physical F-keys via scancodes (survives Fn Lock changes)
• Detects sticky shift, double-tap, and Escape long-press
• Processes events through a state machine that emits high-level actions

See guides/keyboard-architecture.md for technical details.

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Screen Size

Purple Computer displays a 112×32 character viewport (plus header and footer) that fills 80% of the screen. Font size is automatically calculated to fit, clamped to 12-48pt. On typical old laptops (11-15"), this fills most of the screen with a visible purple border.

Minimum supported resolution: 1024×768

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Architecture

purplecomputer/
├── purple_tui/           # Main Textual TUI application
│   ├── modes/            # Play, Music, Art rooms
│   ├── demo/             # Demo recording and playback system
│   ├── content.py        # Content API for packs
│   ├── keyboard.py       # Keyboard state machine
│   ├── input.py          # Direct evdev keyboard input
│   └── tts.py            # Piper TTS integration
│
├── packs/                # Built-in content (emoji, sounds)
│
├── build-scripts/        # Ubuntu ISO remaster build pipeline
│   ├── 00-build-golden-image.sh    # Pre-built Ubuntu system image
│   ├── 01-remaster-iso.sh          # Remaster Ubuntu Server ISO (initramfs injection)
│   ├── build-in-docker.sh          # Docker wrapper (NixOS-friendly)
│   ├── validate-build.sh           # Pre-build validation
│   ├── flash-to-usb.sh             # Write ISO to USB with verification
│   └── install.sh                  # Installation script (runs in initramfs)
│
├── recording-setup/      # Demo video recording and post-processing
│   ├── record-demo.sh             # Full recording workflow
│   ├── apply_zoom.py              # FFmpeg zoom/crop/pan post-processing
│   └── zoom_editor_server.py      # Web UI for zoom keyframe editing
│
├── scripts/              # Development utilities
│   ├── calc_font_size.py           # Auto font sizing calculator
│   ├── generate_sounds.py          # Procedural sound synthesis
│   └── generate_voice_clips.py     # TTS narration generation
│
├── tools/                # AI-assisted content creation
│   ├── doodle_ai.py               # AI art room drawing generation
│   └── play_ai.py                 # AI music room content
│
├── config/               # System configs (Alacritty, X11, fonts)
├── tests/                # Test suite
└── guides/               # Technical references

Stack:

• Target System: Ubuntu 24.04 LTS minimal + X11 + Alacritty + Textual TUI
• Installer: Remastered Ubuntu Server ISO with initramfs hook, Secure Boot support
• Application: Python + Textual + Piper TTS + Pygame

How Installation Works:

There are two separate systems involved:

1. USB Installer (temporary): A remastered Ubuntu Server ISO with a two-gate safety model.

   • Gate 1 (initramfs): Checks for purple.install=1 in kernel cmdline, writes runtime artifacts to /run/
   • Gate 2 (userspace): Shows confirmation screen, requires user to press ENTER
   • Ubuntu's boot stack (shim, GRUB, kernel) and squashfs are untouched

2. Installed System (permanent): A pre-built Ubuntu 24.04 image created with debootstrap. This is what kids actually use.

The USB's only job is to copy the pre-built image to disk (after user confirmation). After reboot, the USB is never used again.

Why this design:

• Ubuntu's signed boot chain → Secure Boot works
• Ubuntu's stock kernel → all hardware drivers included
• No package installation during setup → fast, reliable, offline
• Standard Ubuntu on the installed system → normal apt updates work
• Initramfs hook writes to /run/ → squashfs never modified
• Two-gate safety → explicit user consent before disk writes

See guides/architecture-overview.md for a detailed explanation of why this design exists and what alternatives we tried.

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System Requirements

Target Hardware:

• x86_64 processor (Intel/AMD, 64-bit)
• 2GB RAM minimum (4GB recommended for smooth TTS)
• 16GB storage minimum (the installer requires this)
• 1024×768 display minimum
• Audio output (speakers or headphones)
• BIOS or UEFI firmware (Secure Boot supported)

Tested on: 2010-2020 era laptops (ThinkPad, Dell Latitude, HP EliteBook, Surface, MacBook Air/Pro)

Build Machine:

• Any system with Docker (NixOS, Ubuntu, macOS, etc.)
• 20GB free disk space
• Docker daemon running
• Internet connection (for package download only)

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Documentation

• MANUAL.md: Complete build instructions, customization, and troubleshooting
• guides/demo-system.md: Creating, generating, and composing demo screencasts
• guides/architecture-overview.md: Why the installer works the way it does
• guides/keyboard-architecture.md: evdev input, state machine, F-key calibration
• guides/play-room-design.md: How the Play room parses and evaluates input
• guides/sound-synthesis.md: Procedural sound generation
• guides/mode-reference.md: Reference for all rooms and controls
• guides/kid-proofing.md: Kiosk lockdown and safety measures
• guides/production-checklist.md: Pre-ship checklist

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Philosophy

Computers are a big part of their future. Purple lets them start the way we did: open-ended play, making things, figuring it out.

• Their own computer, a real computer they use and put away on their own
• Building and creating, not watching and swiping
• No Wi-Fi, no browser, no way to connect to the internet
• Your old laptop still works. To your kid, it's a hand-me-down from a legend

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Third-Party Credits

Purple Computer includes code from the following open-source projects:

• spectral.js by Ronald van Wijnen (MIT License): Spectral reflectance data and CIE color matching functions, used for Beer-Lambert paint-like color mixing (yellow + blue = green, red + blue = purple)

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License

Purple Computer is a paid product. Purchase at purplecomputer.org or contact tavi@purplecomputer.org.

The source code is public so you can see exactly what runs on your kid's computer. You're welcome to browse the code and try it out, but please purchase a license before regular use.

See LICENSE for the full Source-Available License 1.0.

Without written permission, you may not:

• Fork, modify, or create derivatives
• Redistribute or republish
• Use commercially

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