The art and engineering of Sega CD Silpheed

Yeah Silpheed is a great example of designing a game around the strengths of its target hardware. Because they were able to focus the art design around what could be streamed at high quality off a 1x CD drive, the FMV works a lot better than it did in games like Night Trap and Wirehead that tried to shoehorn live action video into a console that wasn't capable of displaying it at a decent quality. The actual gameplay is similar to an early 1980s arcade game like Galaga, but I agree with you that the presentation makes it worth playing at least a few levels of Silpheed even now.

I remember when people would talk about a new game they hadn't yet tried and the first question was "How are the graphics?". They truly did amazing work back then to push the limits of systems so they could present things that the machine wasn't expressly built to accomplish.

The soundtrack is absolutely phenomenal. I pull it up on Youtube once a year or so just for kicks.

Silpheed by Sierra On-Line for the PC — ported from the Japanese PC-8801 — was similarly good, possibly the first game I played with a proper sound card. The MT-32 version blew my twelve-year-old mind.

Watching the video linked at the end of the article my first thought was "Starfox, eat your heart out", but watching the gameplay I noted that at its core its a really basic shooter and it can be quite hard to keep track of the enemies and projectiles with the background going nuts like that.

I just saw a video of it. Impressive. Were the enemy ships hand drawn 3D plastered on sprites? Or was there some actual realtime 3D rendered by the CPU? The boss ship I saw looked like realtime 3D.

I manage my RSS by hand (I should really fix this) and update it when I am ready to publish something.

Someone emailed me to tell I had a typo in the URL of the Silpheed article. This must have unlocked the bot maybe?

Summary:

It's low resolution at only 256 x 80, stretched vertically to the screen size.

It's only 16 colors so only 4 bits/pixel.

That comes to 10kb per frame.

A variant of Huffman coding gets it to 3.52kb per frame.

It's at 15 fps and is 12.5 seconds in length.

15 x 12.5 x 3.52kb = 660kb, which fits in a 4mb cartridge.

There is dithering to give the appearance of more colors, and it's done in vertical stripes rather than checkerboards because that compresses better. Then at runtime, every other scanline is offset by 1 pixel, and in opposite directions every other frame, so the dithering blurs back together to give the appearance of many more colors.

So the problem with the Model 1 that the mixing cable is trying to solve is that the expansion port on that model has audio input pins, but no audio output pins. Now strictly speaking, this is sufficient if you just want to use the MD1's headphone jack (stereo) or A/V out (mono), but in addition to the analog audio circuitry not being amazing (though honestly the MD1 is much better than the MD2 here in general) it also imposes a fairly aggressive low-pass filter. This is rather undesirable for 44.1 kHz CDDA. As you note, the mixing cable allows the RCA outputs to be mixed on the CD hardware side which works around this issue.

On the MD2, they added audio output pins to the expansion port in addition to the existing audio input pins. This allows them to achieve the same effect with no mixing cable.

The Sega CD manual says that the RCA jacks are for connecting the Sega CD to a stereo system or stereo TV. I guess they found that doing the sound mixing on the Sega CD made the output cleaner which would have been useful for people wanting to use it as a CD player instead of just for games. The mixing cable is necessary to use the RCA jacks on the Genesis 1 because the system does not have a sound OUTPUT on the expansion connector, only a sound INPUT. The Genesis 2 repurposed a couple of previously unused expansion pins as sound outputs, which let the model 2 Sega CD do the audio mixing without needing a patch cable.

> I think the article is sorta wrong about the sound setup, the Mega Drive I does have a sound input on the expansion port, and mixes it into its sound output.

The Megadrive has a stereo sound input on the cartridge port too, for a total of 3 stereo sound sources (the YM2612, the MegaCD, the cartridge) plus one mono source (the SN76489 PSG).

As far as I know no original release ever used the cartridge input, but nowadays it is supported by many flashcarts to emulate the MegaCD or to provide CD quality audio tracks (MSU-MD and MD+ romhacks), and it has been used by some recent games.

I have a writeup I want to publish about it.

- I felt like Tony Stark inverting Möbius strip to solve time-space navigation with AI.

- Any idea or gut feeling I had, I could verify very fast.

- I had to write a mini Genesis emulator to test the pipeline and it was very pleasant to direct the LLM to write it for me (with clean code and architecture).

Personally, I find LLMs really fun to work with, and the more capable they are the more fun it will get. It's one hell of a force multiplier.

It is fun in a totally different way than programming is. The "fun" or "joy" isn't coming from the sense of accomplishment of writing code or building software per se. Now it feels like it is just the joy of being able to prototype or debug or reverse engineer literally anything at a pace way beyond what you could've ever hoped to before. Have you ever dreamed of developing some software, but realized it was simply too big of a scope for one person? It might not be, anymore, even if you don't go full vibecoder.

The only real problem I ever had with this was the quality of the code. Sometimes it doesn't matter, like for pure prototypes or even reverse engineering, but sometimes it does. My heart sank a bit when I tried Fable to find that it was much better at long tasks and more ambitious in general, but I still didn't like the code much more than Opus 4.7 or 4.8. However, I'm pretty pleased with the code quality of GPT 5.6 Sol. This is a silly thing to care about but I love that by default it doesn't print code comments like a CVS receipt printer adding all kinds of pointless crap that is either apparent from context or irrelevant outside of the conversation you were having. Generally I've also found it to be super good at debugging, usually able to zero in on the actual problem with surprisingly little effort, even with not much context; I wish my debugging foo was that good. I gave Codex a spare machine to test something with real hardware and it has done a fantastic job making use of it.

Then of course there's the problem that I really don't like OpenAI or Anthropic very much. But it seems the news is good there too: even if we assume open weight Chinese models are at least less than 12 months behind on coding performance, then by next year we should have quite a lot of options for how to go about things. Evidence suggests 12 months is probably an over-estimation, and even now I use GLM 5.2 quite a lot at work since it is simply good enough. So... we're getting there too.

Obviously it's a little scary to think the world may need fewer programmers when you are one, and this is maybe not the way that I wanted programming to become accessible and democratized, but beggars can't be choosers. If the future is me being able to run an army of virtual programmers on a GPU cluster, I am interested in seeing what cool shit can be done with it. And when the hype and doom cycle finally ends, I hope everyone else will realize how fucking cool it is, too.

The DOS version has a special place in my heart. I memorized the opening text and thought it was an eerie and cool bit of original poetry, before learning much later that it was a quote from Shakespeare's _Julius Caesar_. I still remember my preferred weapon loadout.

Yeah, it doesn't hold up by today's standards, but it was stunning in its day.

Somewhat enjoyed the (less-visually-impressive) PC version way back in the day, there weren't many good shoot-em-ups on a 286 PC that could barely scroll the screen, but Silpheed played fairly well on it, and IIRC it was one of the few games that supported the non-standard sound card on my parents IBM PS/1. Actually think it might have been bundled with that PS/1

Sounds like a great candidate to watch a LongPlay instead!

I've replayed it hundreds of times. It's pretty fun. I got to the final boss but didn't win.

Agreed, the original is awful too.

I mean, the gameplay isn't amazing. But I wouldn't call it awful. I've played games that are a lot worse... many of which are less fun while also being much less visually appealing. IIRC the sound design for silpheed is good too?