The art and engineering of Sega CD Silpheed

June 1, 2026

The 90's was a decade of considerable improvement in the world of video-game consoles[1]. Each new model brought advanced processing power and better graphics without compromise.

The mid-90s emergence of CD-ROM drives however was an oddity. While the 640 MiB storage was 320x a cartridge capacity[2], the access time (800ms[3]) and bandwidth (single-speed 150 KiB/s) were an eye-watering 4,000,000x and 35x slower.

The Mega-CD was Sega's idea to bring CD-ROM to its Genesis console. Nearly 200[4] titles were produced for the platform. A few great games like Sonic CD, Snatcher, Final Fight CD, and RPGs came out. But an endless series of titles relying heavily on Full Motion Video (FMV) gave Sega's add-on an infamous reputation (Night Trap, Prize Fighter, Slam City, Corpse Killer, Supreme Warrior, WireHead, and A/X-101).

And then, there is Silpheed. Armed with exquisite artistic taste and an engine capable of jaw-dropping animation, it made the press go wild[5][6]. Players pondered what was real-time 3D and what was pre-calculated[7]. It received praises which, to this day, persist[8][9].

For those still unimpressed, keep in mind these near-fullscreen cutscenes run on a 12.5MHz m68k CPU, use 16 colors, and consume 150 KiB/s. With 16-bit 16kHz music, the 15fps video stream was left with a mere 8 KiB per frame.

I spent the past two weeks reverse engineering the FMV format in my spare time. That was a departure from how I normally work since I did not write a single line of code. I will likely write something about my A.I framework (and opensource it) next month. But I can already tell this is an overall pleasant way to work.

The following is what I came up with. And if you want to see all of the cutscenes and gameplay background videos to get accustomed to the topic, here is a storyboard I created with the tools I designed (I can't really say I "wrote" them).

Sega-CD internals 101

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