The voices of Konami's arcades return
You may remember the sound of a game before you remember the images: the roar of a crowd, a shouted warning, a tune coming through a wall of cabinets. Konami's 054539 sound chip powered X-Men, Run and Gun, Premier Soccer and dozens more. The JT cores for these games have been around for a while already. But sadly, some of those recorded voices and effects have been missing from the experience for over twenty years unless you had access to a working original board.
That changes with today's version of JT539. We have completed the reverse-engineering work and brought the chip's filters, stereo echo and sound shaping back into the FPGA core. These details give the samples their original character: a voice cuts through the music, a note softens at just the right moment, and an echo fades away as it did in the arcade.
After all these years, we are all used to the emulator sound and very few people can experience the original feeling... until today.
Die shots meet the real board
This result rests on two kinds of evidence. Furrtek photographed and traced the silicon die, turning its logic into schematics and Verilog. We then probed a real X-Men board to check the behavior that schematics alone cannot settle, including the fine details of timing and arithmetic. Each approach helped check the other, giving us a remarkably complete picture of the chip.
For the final check, we replaced the sound program ROM on the board with a Pico-based test program and recorded the real chip's output. We compared 196 recordings—more than 6.4 million samples—against JT539, one sample at a time. The result was zero mismatches. The measured behavior now agrees exactly across those tests.
The video accompanying this post walks through the chip, the reverse-engineering work and the listening comparisons. One of our project collaborators offered to make it so everyone could see the scale of this achievement. It uses AI-generated narration and imagery; we know that style is not for everyone, and want to be open about how it was made. We are grateful they took the time to help us tell this story.
Three more games for the arcade
Dragon Buster (Namco, 1985) sends you through branching paths, monster-filled corridors and guarded rooms on the way to the Dragon's Mountain. Its double jump is a delight, and timing a downward sword swing around a jump can deal triple damage. It joins Sky Kid in a new core contributed by Marc Emmerson (memmerson). Both games are available directly as public releases.
The original Sky Kid joins the lineup too. This is the original game, in its newer ROM revision—not Sky Kid Deluxe, which is already supported in another core. Take to the sky, strafe enemy positions and loop around for another pass.
Escape Kids is Konami's four-player cross-country race. Buy your ticket, decide how to spend the money left on upgrades, and try to beat the racer in black to the finish. It has a wonderfully odd sense of humor: lose, and the game sends you down the toilet. Winning races unlocks a bonus stage where you can earn extra cash by riding straight into the trash cans.
Escape Kids joins the SIMSON core, which returns to beta briefly while this new game is prepared for players.
Other Updates
Minor bug on the OutRun gear feature published recently fixed [niknak]
System 18 audio levels are finally correct after a bug in a register write was fixed [niknak]