What you see is the same ROM that will go on the cartridge, run by Stella, the Atari 2600 emulator, compiled to WebAssembly. It emulates the 6507, the TIA and also the ARM processor of the ELF cartridge, so the game runs on its real code, with no adaptations. On the title screen, the button opens the menu to pick the language and the display mode; SELECT pauses the game and lets you save or load, and the saved game stays in this browser as if a SaveKey were plugged in.
Liber IX
Play
The cartridge, as is, in your browser.
Build of 2026-11-01 17:53 · commit a821ffb · 142 KB ROM, 146 KB Chameleon ELF, 197 KB zip · MD5 40b6f804e048fa14fe101d6a30d00716 · download the ROM
Controls
| Action | Keyboard | Gamepad | Touch |
|---|---|---|---|
| Walk | ↑ or W | D-pad or stick up | Pad, up |
| Turn | ← → or A D | D-pad or stick | Pad, sides |
| Move Adso aside | ↓ or S (held) | D-pad or stick down | Pad, down |
| Button (drop object, yes, leave the scroll) | Space, Z, X or Enter | A, B, X or Y | FIRE |
| SELECT (pause, save, load) | 1 or Tab | Select / Back | SELECT button |
| RESET (back to the title screen) | R or 2 | Start | RESET button |
| Height map (left difficulty) | P, M or 3 (held) | L1 or R1 (held) | MAP button (held) |
| Show the FPS (B/W switch) | B | — | FPS button |
The keys only work while the emulator has focus: click on the picture. The mirror trap is button and down at the same time, as on the cartridge.
Settings
| Button | What it does |
|---|---|
| TV | NTSC, PAL 60 or PAL 50. The cartridge is told which system it is on and the console restarts, as if you had changed machines. At 50 Hz the game runs at 50 frames per second, like on a PAL 2600. |
| Phosphor | Blends each frame with the previous one, like the persistence of a CRT. It softens the flicker of the FULL and DOUBLE modes, which alternate two fields at 30 Hz. Off, it looks the same as a modern screen plugged into the console. |
| Sound | Mutes or enables the sound. Browsers only play audio after a click, which is why you have to press "Play". |
| Touch controls | Shows the pad and the fire button over the picture. On touch screens they appear on their own. |
| Slow pace | The right difficulty switch. The game takes the position it is in when the console is switched on as the fast pace, the original's nominal one: one tick every 0.12 s. When on, the slow pace the Spectrum was played at, which, walking, gives 6.5 ticks per second instead of the 8.3 of its 6-frame wait: each tick lasts 28% longer. It can be changed at any time, and the scoreboard shows the chosen pace for about two seconds. |
| Full screen | The picture as large as it fits, keeping its proportions. The controls go in the bands at the sides (top and bottom when the phone is upright): sound, phosphor, FPS, pace and the pad on the left; SELECT, RESET, MAP and fire on the right. On the iPhone, whose browser has no full screen, the game fills the whole window. To leave, press Esc or the ✕ button in the corner. |
Saved games
The emulator has a SaveKey in the right port. When you save from the SELECT menu, the game goes to the EEPROM of that SaveKey, which here is stored in the browser (IndexedDB) a few seconds later, and when you pause or close the tab. It stays as long as the site data is not cleared, and it does not travel from one browser to another.
License and source code
The emulator is Stella 7.0, by Bradford W. Mott, Stephen Anthony and the Stella team, with the ELF cartridge emulation by Christian Speckner. Stella is distributed under the GNU General Public License, version 2 or later, and so are this WebAssembly build and the web layer that comes with it (the windowless setup, the video and audio output and the controls), written by Juan Sánchez Jurado. No Stella file has been modified: the additions are separate files compiled together with the core, and those that replace a Stella file keep its copyright notice and explain what they change.
This emulator is distributed in the hope that it will be useful, but without any warranty, without even the implied warranty of merchantability or fitness for a particular purpose. See the license and Stella's copyright notice for details. You may redistribute and modify it under the terms of the GPL.
As the license requires, the complete corresponding source code is available right here: the Stella 7.0 files that get compiled, the web layer, the Makefile and the JavaScript of this page. The original lives at github.com/stella-emu/stella.
The game ROM is not part of the emulator: it is data loaded into it, like a cartridge into a console. Its rights are those of the demake and of the original Opera Soft game.