Retrogaming on Mac: Getting started with OpenEmu

I started retrogaming when it was cutting edge gaming, and I still have all the hardware I accumulated along the way. And while I still enjoy dusting off an old machine and loading some forgotten format into a reader no longer made, I have grown into an Apple ecosystem user… and appreciate when something is simple and just works. I’ve toyed with the more complicated setups of individual emulators, and due to Atari allegiance have gotten a few of those working in the past, but it is with OpenEmu that the world of emulation has become simple and just works for Macs.

Before you start, figure out where you are going to store some files. Like a lot of files. Millions of little bitty files… and thousands of big fat ones. We are talking dozens to hundreds of gigs of stuff, depending on how complex you want to get at the start.

Download OpenEmu… not the big red “download” button, but the little red text underneath that says Experimental. This is the version that is starting to offer support for the MAME engine for arcade machine emulation. There will be warnings that MAME is not fully supported yet, but this is currently the best and easiest way to go.

OpenEmu is something called a frontend: it organizes the files needed for other programs, the emulators themselves, to run the game ROMs. ROM is an acronym for Read Only Memory, a type of chip used in things like game cartridges to hold the actual game program. Loading a ROM file into an emulator is like sticking the cartridge into your Atari 2600. OpenEmu works as a middleman to stick the right ROM files into the right emulators.

In addition to ROMs that are similar to cartridges or program files, there are ROMs that are more like operating systems. Because of the nature of copyright law, some emulators cannot be distributed with the ROM files from the machines they emulate; these files must be found by the user. Thanks to the Internet Archive, these files are easily found. The OpenEmu BIOS Pack includes all the files needed to activate the different cores, or machine emulations. Download and extract the files to your chosen storage location, then go to OpenEmu and select Preferences… System Files. You will see a whole list of warning symbols that we want to turn into green checkmarks. Just drag the files to the System Files window and OpenEmu will know what to do with them.

When all our checkmarks are green, OpenEmu is ready for some game ROMs. The Internet Archive Software Collection is your best friend in this process. This page links to libraries of archived software for different machines, and perhaps most importantly of all, for archived arcade machine ROMs… MAME ROMs.

MAME (Multiple Arcade Machine Emulator) is the gear OpenEmu kicks into when it is time to emulate arcade machines. While it is astonishing that MAME can do what it does, there is a certain amount of learning curve in getting MAME to sing to your tune. OpenEmu takes a lot of that confusion away for you, but there is still one thing you have to do correctly for all this to work: get the right MAME ROMs. In particular, the right MAME ROMs for OpenEmu’s version of MAME is 0.149. This is the sort of thing you are looking for. Download, extract, and drag the files into OpenEmu’s Arcade Library window.

At this point (well, after OpenEmu does a huge amount of chewing. Maybe you shouldn’t have dropped all 20K or so files on there at once, after all), you should able to play at least some of your old arcade favorites. If you downloaded the full MAME ROMset, there will be a lot of files that are for gambling machines that aren’t going to seem to work at all… and some of your favorites won’t look right, or may not run at all. This gets into more advanced MAME issues, and I bring it up here just so you won’t think there’s something broken.

At this point, it’s time to play around with your console emulators. I’m a longtime Atari guy, so those are the first ones I checked out. Once you have installed the BIOS ROMs mentioned above, you will just need game ROMs to play. Rather than downloading entire sets (this was important for MAME mostly because of how difficult it is to reliably source individual files from a particular ROMset version), I found a few sites where it was relatively easy to download individual ROMs, Planetemu.net and CoolROMs.com.au being a couple I used most often. I also found the very interesting ROMCollector.com; if you decide you do want to have a full archival ROMset for some of these emulators, it looks like this guy has done the hard work for you.

One more thing about OpenEmu: the controls. In general, OpenEmu has a best guess as to how to map keyboard keys to game functions. You can open Space Invaders and expect the arrow keys to move your base left and right, and depending on what system you are emulating, there will be some key that fires. You can edit these settings, including telling OpenEmu to use attached controllers, in OpenEmu’s Preferences… Controls section. It may take a little while with some games for you to figure out your controller mapping, but it’s worth it if you happen to be, say, a Robotron 2084 fan who figured out how to set up his Logitech F310 controller’s two joysticks to move and fire like in the arcade. I lost minutes figuring it out, then I lost hours enjoying it. Also, if you do take the time to map something special like this, make some manual note of the settings: I’ve not been able to figure out how to make OpenEmu save game specific controller configurations.

Discussion thread for this post in the jjewell forum.