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.

A third-party Dreamcast SD adapter.

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.

[Thanks to cass for the tip.]

10 thoughts on “Dreamcast Homebrew Gets Boost From SD Card Cache

  1. Dreamcast is an excellent modding platform.

    Often the piracy is blamed for its downfall but in fact SEGA simply had a succession of mismanaged launches and ended their career as console makers.

    The DC had some brilliant innovations the VMU was cute and useful but this was tempered by some absurdly bad “innovations” like the gamepad which had abysmal ergonomics.

    1. I think it’s more that the PS2 came out shortly after and has superior graphics and backwards compatibility. DC was a bit ahead of it’s time with the modem attachment but it was underutilized because dail-up is crazy slow. The most disappointing part of the DC was they skimped on RAM.

    1. Single analog stick, adjacent to a 4way dpad? Wire comes out of the bottom as though you are sitting on the console? Analog stick becomes painfully rigid with time? Fine?

  2. That’s very interesting RAM is the achilles heel of the DC everything else about the system is incredibly well thought through but it really could have done an extra 16mb. We don’t get virtual RAM here but the opportunity to reduce our overheads. So in theory we can read from two places at once and with some virtual memory wizardry could free up some RAM on the Dreamcast. Got lots of potential for ports mods and homebrew.

  3. Don’t remember there being much need for this back when crt0 and I released our port (id had previously made a port, but never released it to the public). I even had split-screen multiplayer in the KOS os-mode build. There was *just* enough room to have two full copies of the game running at the same time on a desktop.

  4. Hi Grizzly, There is not when your running 320×240 this running 640×480 and bba online.. Main point is here i can stream the data off one src and stream cdda stereo on the main.. with no impact I remember crt0 great coder :) Also read write so i can use it as network cache.. Great too see you about :)

  5. Interesting hack, I guess these games don’t lend themselves to the kind of disc based streaming that Crazy Taxi used. In that game parts of the level were streamed in as needed from the GD-ROM.

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