Emulator · July 2026 game-runner update · Build 66
Choose an authorised Jupiter Ace ROM, then choose a TAP or simple TZX file. This is a public work-in-progress build: try any TAP, but expect some titles to need future compatibility profiles. The runner can now remember your selected ROM in this browser for future sessions, then load the TAP immediately using the Jupiter Ace ROM for dictionary files, attempt automatic launch, and switch from fast loading to 100% Jupiter Ace gameplay speed. Build 66 adds Rocks 'n' Ghosts cursor-key/QAOP mapping and root-level sitemap.xml and robots.txt for launch indexing.
Automatic launch
The runner resets and warms the ROM, loads BYTE data into its recorded address, passes DICT blocks through the ROM’s own LOAD process, and then starts the detected launch word without a separate Run button. If you save a ROM in this browser, future visits can skip the ROM-selection step.
Built-in profiles remap the host controls to the original keys used by recognised game releases. Recognised arcade games use remapped controls; unidentified software starts in full-keyboard mode so text adventures, utilities and number-key games remain usable, while cursor keys can still alias QAOP-style movement mappings when relevant.
Compatibility note: this is a work-in-progress compatibility-focused game runner, not a guaranteed complete Jupiter Ace emulator. You can try any TAP, but some titles may fail until a specific compatibility profile or load sequence is added. TZX loading is experimental: this build extracts simple standard-speed TZX blocks, including blocks with a leading tape flag byte, but advanced/custom TZX loaders, timing-sensitive recordings and unsupported peripherals may still fail.