Apple IIe Emulator

A fully functional Apple IIe computer emulator written in ES6, running entirely in your web browser.

Quick Start

Try it Now

Click any game below to launch the emulator with that disk loaded:

Operating Systems:

• ProDOS 2.4.2 - Apple's professional disk operating system

Games:

• Adventure - Classic text adventure
• Bad Dudes - Action beat 'em up
• Beyond Castle Wolfenstein - Stealth action
• Burgertime - Arcade classic
• Castle Wolfenstein - Original stealth shooter
• Cause & Effect - Puzzle game
• Jeopardy - Quiz game
• Lode Runner - Platform puzzle classic
• Oregon Trail - Educational adventure (2 disks)
• Rampage - Arcade destruction
• Star Trek - Space strategy

Using the Emulator

Loading and Booting Disks

Step 1: Load a Disk

1. Click on "Drive 1" (or "Drive 2") to expand the drive settings
2. Choose one of the following:
   • Browse - Click the browse button to select a local .dsk file from your computer
   • URL - Enter a URL to a .dsk file, then click "save..."

Step 2: Boot the Disk

3. Click the reset button to boot the disk

That's it! Most disk images will auto-boot after reset.

Tips:

• Hold Shift while clicking reset for a cold reset (clears memory) - useful if a disk won't boot
• Regular reset does a warm reset (preserves memory)
• You can also load disks via URL parameters: ?u1=URL for Drive 1, ?u2=URL for Drive 2

Controls

Keyboard:

• Standard keyboard input works as expected
• Ctrl key combinations work for Apple IIe control codes
• Arrow keys are mapped appropriately

Gamepad/Joystick:

• Connect a gamepad (tested with PS4 controller)
• Analog sticks control paddle/joystick position
• Buttons map to Apple IIe joystick buttons

Display:

• run/stop - Pause/resume emulation
• reset - Reset the computer (hold Shift for cold reset)
• Volume slider - Adjust audio volume
• full screen - Toggle fullscreen mode
• Text/graphics color selectors - Choose display colors
• Scanline options - Toggle scanline effects for authenticity

Features

Emulated Hardware

• CPU: W65C02S processor with full instruction set
• Memory: 128KB with extended memory support
• Display:
  • Text mode (40/80 column)
  • Lo-res graphics (partial)
  • Hi-res graphics (280×192)
  • Double hi-res graphics (560×192)
• Peripherals:
  • 5.25" floppy disk drives (2 drives, read-only)
  • Sound/speaker
  • Joystick/gamepad support
  • Keyboard

Current Limitations

• Disk writing: Not yet supported (disks are read-only)
• Disk formats: Only .dsk format supported (.po, .2mg, .img planned)
• Lo-res graphics: Partial implementation
• Expansion cards: Not yet implemented

Development

Running Locally

Start a local web server:

sh http_server.sh

Then navigate to http://localhost:8000

Testing

The emulator includes the Klaus Dormann 6502 test suite for CPU validation. See kd_test/README.md for details.

Project Structure

• w65c02s.js - CPU emulation
• memory.js - Memory management
• motherboard.js - Main system integration
• display_*.js - Video display modes
• floppy525.js - Disk drive emulation
• keyboard.js - Keyboard input
• joystick.js - Gamepad support
• apple_audio.js - Sound emulation
• io_manager.js - I/O coordination

License

Released under the GNU General Public License https://www.gnu.org/licenses/gpl.html

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John Clark, 2018