What’s MIL-CD?

Did you know that GD-R was not the only exclusive format which Sega adopted for the Dreamcast? Sega also implemented compatibility for a format known as, MIL-CD but what was it?

Sega had big plans for the MIL-CD format

It's not clear what the MIL in MIL-CD stood for with some observers suggest it was an abbreviation of Millenium, a popular topic of the time but what is clear is that is was a proprietary compact disc storage format created by Sega in 1998 in an attempt to add multimedia features to normal discs when used on Dreamcast. They look like regular CD-ROMS but combined with the Dreamcast’s (for the time) advanced MPEG SofDec capabilities would allow gamers to watch full screen high-quality video that was far superior to VHS, the video standard of the time (although lacked VGA support).

Sofdec allowed for MPEG video with a frame rate of up to 60 frames per second

The format also would enable developers to implement multimedia experiences similar to what we’ve now come to expect from DVD/BluRay discs like video and still-shots, deleted scenes and related real time access to internet pages; all of which would be navigated using the Dreamcast controller. Not only that, but as the disks were split into two sections, one with the audio tracks and the other with Dreamcast-compatible digital data, MIL-CD's also operated as good old audio discs.

A little bit of trivia is that this wasn’t the first time a company attempted to encode digital data on compact disks and market the products for use in audio CD players. Back when audio tapes were still the norm, the CD+G (graphics) format was introduced as an extension to the then budding audio compact disk format and the format was even used by NEC in their PC Engine/ TurboGrafx CD add-on.

Hudson also attempted to create its own digital format with the PC Engine CD

Despite the potential the Dreamcast only receive 8 official MIL-CD titles during its lifetime with most being generic J-pop trash from the 90s. With remixed tracks and exclusive Ulala featuring videos, the Space Channel 5 soundtrack is obviously one of the more sort after discs from the lineup and can demand a fair price at auction.


Kitahe White Illumination Pure Song and Pictures

Chekki Musume Miru CD

Heartbreak Diary

Himitsu Original Soundtrack

09 Chairs

D2 Soundtrack



Space Channel 5 soundtrack

Of course, as a proprietary format MIL-CD failed to overcome Toshiba and Matsushita’s superior DVD format and eventually allowed hackers to bypass the Dreamcast’s security, creating a rather significant piracy market for the system and in more recent times enabled gamers to play newly produced homebrew titles. In response to this security hack Sega actually removed MIL-CD compatibility from later systems which stopped pirated games from being playable but significant to gamers these days is that it removes the ability to play the aforementioned homebrew titles. To check if your Dreamcast is MIL-CD compatible please see our guide.