Running CHIP-8 on a Vintage Mac

Retro gaming and computing seem to be hotter now than ever before. Whether this is due to nostalgia among those that grew up with these systems or the curiosity of younger generations is hard to say. But whatever the case may be, people just can’t get enough heavily-pixelated goodness from these aging machines.

Not everyone is interested in filling up an entire room with the yellowed plastic cases of vintage equipment, however. So many retro enthusiasts turn to software emulators to get their fix. The more technically-inclined individuals among this generally technically-inclined group will eventually start to wonder what makes these emulators tick. How can modern hardware run the software from a completely different architecture that is over 40 years old?

The best way to understand this is to build your own emulator. But even building, say, an Atari 2600 emulator, is going to be a long journey that takes you deep into the weeds. As such, it would generally be better to set the bar a bit lower when getting started. YouTuber KenDesigns recently highlighted an excellent option called CHIP-8.

CHIP-8 was a programming language that was developed in the mid-1970s to serve as a middle ground between assembly and BASIC. It was easier to program in than assembly language, yet was more efficient than BASIC. CHIP-8 was not just a language, however. It ran inside of a virtual machine, which had its own instruction set and means of producing graphics and sound.

To better understand how it works — and just for the fun of it — KenDesigns decided to build a CHIP-8 emulator. And to make sure the project was appropriately retro, the emulator does not run on a modern machine, but on vintage Apple computers such as the Macintosh 128K.

Or more accurately, the emulator runs on the Motorola 68000 CPU. When booting up on a Mac it runs on the bare metal, bypassing the system ROM completely. This would normally be a bit of a challenge to pull off, but KenDesigns was able to make it happen with Chip4Mac68000. This is a bare-metal SDK he has designed that works with a large number of 68000-based Macs.

If you want to try out CHIP-8 on a Mac for yourself, you can load it onto an 800K disk and run it on original hardware. Or if emulation is more your speed, it is possible to run this emulator on a Mac emulator (it’s emulators all the way down!) — but be warned, not all emulators will work.

In the video, KenDesigns tests out a few games and graphical demonstrations that take advantage of CHIP-8’s 64x32 monochrome graphics. He also goes into more detail about how the emulator works, so be sure to give it a watch if you are interested in digging deeper.