Dreamcast Homebrew Gets Boost from SD Card Cache

While it might have been a commercial failure compared to contemporary consoles, the Sega Dreamcast still enjoys an active homebrew scene more than twenty years after its release. Partly it’s due to the fact that you can burn playable Dreamcast discs on standard CD-Rs, but fans of the system will also point out that the machine was clearly ahead of its time in many respects, affording it a bit of extra goodwill in the community.

That same community happens to be buzzing right now with news that well-known Dreamcast hacker [Ian Micheal] has figured out how to cache data to an SD card via the console’s serial port. At roughly 600 KB/s the interface is too slow to use it as swap space for expanding the system’s paltry 16 MB of memory, but it’s more than fast enough to load game assets which otherwise would have had to be loaded into RAM.

In the video below, [Ian] shows off his new technique with a port of DOOM running at 640×480. He’s already seeing an improvement to framerates, and thinks further optimizations should allow for a solid 30 FPS, but that’s not really the most exciting part. With the ability to load an essentially unlimited amount of data from the SD card while the game is running, this opens the possibility of running mods which wouldn’t have been possible otherwise. It should also allow for niceties like saving screenshots or game progress to the SD card for easy retrieval.

[Ian] says he’ll be bringing the same technique to his Dreamcast ports of Quake and Hexen in the near future, and plans on posting some code to GitHub that demonstrates reading and writing to FAT32 cards so other developers can get in on the fun. The downside is that you obviously need to have an SD card adapter plugged into your console to make use of this technique, which not everyone will have. Luckily they’re fairly cheap right now, but we wouldn’t be surprised if the prices start climbing. If you don’t have one already, now’s probably the time to get one.

To be clear, this technique is completely separate from replacing the Dreamcast’s optical drive with an SD card, which itself is a very popular modification that’s helped keep Sega’s last home console kicking far longer than anyone could have imagined.