The State of Saturn Emulation on the PS4

You must play Sega Saturn, as we say here at Shiro, and that means by any method available.

But one method we haven’t covered so far has been emulation on the PlayStation 4. It’s not quite as easy as dragging a CUE file onto Mednafen’s executable on your PC, let alone just firing up actual Saturn hardware. So it’s fascinating to see the lengths people will go to run Saturn games on a modern console.

Let’s take a look.

---

First, a little background: Retail games for the PS4 are PKG, or package, files. When you start one up, it checks for whether the user has an official license to run it.

People in the hacking scene found a way to convert official games into FPKGs, or fake package files, that trick the PS4 into thinking that the user running them has a license to do so.

It’s easy to imagine doing that for, uh, let’s say backups of your PS4 games, but how would a Saturn game run on the hardware? Wouldn’t you need an emulator ported to PS4?

Enter City Connection.

The publisher’s Saturn Tribute releases of Cotton 2, Cotton Boomerang and Guardian Heroes in September 2021 were made possible by porting a previously PC-exclusive Saturn emulator, SSF, to the PS4 and Nintendo Switch. Each game comes with its own instance of the emulator as well as a Unity wrapper to enable extra options like save states and button remapping.

Upon their release, a Polish hacker named Jabu took an interest in what he could do with them. He’d already made utilities that injected PS1 and PS2 games into emulators and converted them into FPKGs to run on PS4, so he looked into whether he could do the same with City Connection’s Saturn offerings.

Sure enough, in December 2021, he made public a utility simply called Saturn-fpkg that takes an original Saturn game, injects it into the emulator of one of the Saturn Tribute games, then converts it into an FPKG that runs on its own on a jailbroken PS4. It can even be given a unique icon and splash screen.

He made a video at the time showing how to use his utility:

Shiro reported on hackers doing something similar with the Switch version of the Saturn Tribute games.

One weakness of Saturn-fpkg is that each Saturn game must be converted one at a time. It could be a bit monotonous to run a library of hundreds of games through the program.

But the process was made easier in late April this year, when a French-speaking hacker named Markus created a batch script named Saturn2PS4 that converts Saturn games en masse into PKG files.

He updated it a couple weeks later to version 1.1 to add support for more file formats, to add Spanish and Italian translations to the menu, to provide an option to disable widescreen and to fix a bug.

Like Jabu before him, Markus made a video — albeit while speaking French — showing how to use his utility:

I would be remiss not to mention one other method of emulating Saturn games on a PS4: RetroArch. The framework that runs a variety of retro console emulators on the Libretro platform was unofficially ported by homebrewers Frangarcj and Big Boss in January 2019 and made public a year later. It provides a way to run Mednafen — called Beetle in RetroArch — and Yabause, both popular Saturn emulators, on PS4.

It was made possible by using a set of homebrew PS4 libraries called liborbis, enabling usage of OpenGLES 2, a graphical user interface.

On PC, RetroArch downloads its emulator “cores” from the Internet, but that’s not possible for its unofficial PS4 port. So a separate core installer that’s been preloaded with all the cores must be run on the console before running the main RetroArch FPKG.

Sadly, RetroArch only runs on a PS4 using firmware version 5.05, making the versions that use City Connection’s port of SSF more appealing for those on firmwares newer than that. In addition, having to start up RetroArch first before playing a game adds an extra step that’s eliminated with the FPKG converters above.

Saturn-fpkg, Saturn2PS4 and even RetroArch make it look pretty easy to get Saturn games running on a PS4, but not so fast. These won’t work on a stock console — it must be modified first so that it can run custom firmware called GoldHEN. Developed by a hacker named Sistr0134, GoldHEN allows users to run unsigned code — code not permitted to run by official means, essentially — on a PS4. It also allows for transferring games via the console’s USB port onto its hard drive.

And to run GoldHEN, a PS4 must first be jailbroken, a process of exploiting a locked-down device’s flaws to install software that the manufacturer didn’t intend for users to run. Describing how to jailbreak a PS4 is … beyond the scope of this story, but as with anything, some well-phrased terms in a search engine can be helpful for anyone researching such things.

And you won’t even be able to do anything described above if you’re running the PS4’s latest official firmware, version 10.5. While it’s possible — perhaps even likely, knowing the tenacity of hackers — that a way to jailbreak that version eventually will be developed, for now, only those running earlier firmwares like version 9.0 or earlier can jailbreak their consoles. And there’s no known way to roll back a PS4 to an earlier version of the firmware … yet.

So running Saturn games on PS4 is only possible for those with the foresight to eschew Sony’s official firmware updates or for purchasers of new-old stock of untouched consoles that shipped with older firmwares loaded onto them. Still, it’s clearly an active scene that will continue to evolve and make it easier for players to do as Segata Sanshiro says: play Sega Saturn.