Today’s video games are frequently patched and expanded to fix bugs, introduce content, or add new modes. Arcade titles from the 1980s and ’90s followed a similar pattern, albeit in hardware form: multiple distinct revisions were released as developers refined gameplay. The original Mortal Kombat, for instance, shipped in several different builds over time.
Those mid-’90s updates were distributed on physical ROM chips and had to be installed by arcade owners. The Ultimate Mortal Kombat 3 upgrade — which arrived about six months after the initial Mortal Kombat 3 release in 1995 — was delivered this way. Midway also developed a rarer build called the Ultimate Mortal Kombat 3 WaveNet Edition, which was intended to add online competitive features and include playable variants such as Noob Saibot and Human Smoke.
WaveNet Edition never saw a broad release. It was trialed in a handful of arcades in Chicago and San Francisco, but the networking costs proved prohibitive: operators were reluctant to pay for the expensive dedicated T1 lines the system required.
Because the WaveNet ROM image was never widely distributed or dumped, it remained effectively lost — until the release of Mortal Kombat: Legacy Kollection from Digital Eclipse, which makes the WaveNet build playable again for the first time in decades.
Stephen Frost, head of production at Digital Eclipse, says in a Zoom interview that rediscovering WaveNet was unexpected: the team had assumed the odds of finding such an obscure test build were slim, given how poorly the industry preserved its own history.
WaveNet was so obscure and short-lived that it wasn’t an obvious target during the collection’s early research phase. The idea to chase it down came after a prompt from Stephanie Brownback, the QA lead at NetherRealm Studios, who suggested the Digital Eclipse team look for the WaveNet build.
The ROMs were ultimately located through Mike Boon — Ed Boon’s brother and an engineer at NetherRealm — who had preserved some old hardware and files. Although the team couldn’t recover original source code, Boon provided a dump of the WaveNet ROMs that became the basis for emulation work.
Emulation programmer Daniel Filner, who previously contributed to projects such as Atari 50 and Teenage Mutant Ninja Turtles: The Cowabunga Collection, examined the dump and began adapting it to his Moo Emulator.
Filner describes the dump as roughly 25–26 files. Arcade PCBs often contain many discrete ROM chips — several for graphics, a few for sound, and others for the main program — so his first step was matching the files to known naming conventions used by resources like MAME.
He found that the audio and graphics ROMs matched existing UMK3 data; the primary differences lived in the main program ROMs, which contained balance tweaks, bug fixes, and other gameplay adjustments. That meant his effort focused on getting the altered main program running under emulation. A separate uncertainty concerned WaveNet’s networking: would the game fail if it couldn’t reach Midway’s servers?
Filner reports the game handles the absence of a network gracefully: if no connection is present, WaveNet simply writes its intended modem data into a memory buffer, pauses briefly, and then continues booting as a standalone arcade game — essentially falling back to normal gameplay without crashing.
In the Legacy Kollection, WaveNet Edition is the only included arcade title that displays its full boot sequence and POST (power-on self-test). Filner notes that any server-side features — such as the WaveNet news items the cabinet would have attempted to download — are irrecoverable without access to the original server files or a preserved PC that once hosted them.
