At 2:15 I might have derped and actually forgotten to switch the screen mode to 0 before recording that footage :/ The text characters should be 6x8 rather than 8x8. Hopefully it still gets the point across - just imagine the text characters being a bit thinner! Or you can try it out yourself at the provided link.

the flux segment made me think that maybe someone could port vib-ribbon to the sega cd

The “weird gfx corruption” and dots are called color dots. It’s because you’re writing palette ram during operation. So when it goes to read palette ram for that pixel, it gets whatever you’re writing.

Just a few notes (yes I literally took notes).

The sprite zooming function the Master System has in Mode 4 was actually inherited from the TMS9918 VDP, where it did actually work correctly. There is actually Master System releases that do take advantage of the zoomed sprites too, all of them being TecToy releases in the 90s. Earthworm Jim is a pretty famous example.
Virtua Fighter Animation for the Game Gear (same architecture) also takes advantage of zoomed sprites, and that's as a first party title from Sega of Japan.

CRAM writes causing colour dots is a persistent issue in both Modes 4 and 5, but it isn't actually something that HAS to happen. I recommend checking out Sonic 3 & Knuckles completely avoiding the issue in spite of being full of CRAM writing mid-frame. I am interested if you'll cover this. :P

I know you mostly focus on contemporary games for these consoles, but there is a pretty big burgeoning scene for Mega CD Mode 1 hacks and homebrew. Particularly notable examples include the "Road Rash 3 Improvement" hack that spins off the renderer thread to the Mega CD's 68k CPU (sadly not to the ASIC, so you still have the 4bpp-inside-8bpp chunkiness issue),  as well as the downloadable WIP version of Arkagis Escape.

I usually wouldn't give such a thorough rundown on the first two points, but people do look up to you pretty heavily y'know. :P

EDIT: Made my comment slightly less cheeky. I was waking up when I wrote this and my ego was too large. @_@

Sonic 2 also uses H32 for special stages, making it a good test game for mod comparability.

A fun fact about H32 is that it's more compliant with NTSC sync timings than H40, with the hsync pulse width being slightly too long in H40. This is partially why the Zenith fix exists and was even almost integrated into the mega jet.

Pier Solar (released in 2010?) was a cartridge game had the ability to read data from an enhanced music cd in the attached sega cd.

Y'all remember Sonic Shuffle? Amazing. I had that one on my Dreamcast.

9:15 the dots while changing colors can be avoided by changing them while the beam is left or right of the screen.
Some Sonic 3 or Rocket Knight water levels uses this trick for water and they have not dots on screen, so they dont need sprites to hide it.
About 7:10 MegaCD "mode 1", a lot of modern homebrew games use it as optional enhanced OST. Even there is some extra hardware that lets you use Mode 1 in old games.

My favorite shadow/highlight thing is the title screen of Toy Story. It’s used to make a much higher bit depth image. Also nice for an emu author as it helps you easily troubleshoot it…

256x224 was a common resolution for lots of systems so it indeed makes sense to use H32 mode for ports and multiplatform games to make the art look (more or less) the same, but the MD port of Double Dragon is a peculiar example where the arcade original ran in 256x224 resolution, but the MD port reuses the same art assets while running in H40 resolution. As a result the graphics look squashed and movement speeds are a bit wonky compared to what they should be, but a funny quirk of playing it on modern setups is that if you play the game stretched to 16:9, it effectively restores the original aspect ratio and looks more "correct". There are some SNES games like The Lion King and Earthworm Jim where 320 resolution art get awkwardly cropped and stretched to fit on the 256 pixel canvas, but MD Double Dragon might be the only game I can think of where the opposite happens...

The “The Adventures of Batman & Robin” (Genesis) in the thumbnail is what got me to click on this video. (even if it’s just for the graphics and NOT the music…)

There is some homebrew stuff that use the Mega CD's mode 1, at least I think. The most notable example is Doom CD32X Resurrection, which splits it's assets between the cartridge and disk.

It is also not uncommon to see genestis games that have optional Mega CD functionality for custom music during gameplay, but I suspect that's different.

Just one note. Its not the system that put Itself in mode 4. Its the game code Itself. Its actually possible for a Master System game to use Mode 5 on a Mega drive. Its just that no Master System game bother to detect that its running on a Mega drive and than switch to, but that would be actually possible.

Awesome vid, I was doing research on this subject myself recently. Something I'd like to note at 4:52 is that the sprite zoom mode originates from the SG-1000 and not the Master System's mode 4. If you'd like an example, Girl's Garden uses it for the player, clouds, and the boy sprites during Challenging Stages.

Even though I already knew a lot of this information, it's nice to have it organized together in one whole video.  I'll definitely look to this and share it with others that are curious or trying to learn about the hardware. 😇

Since I happen to be familiar with it just thought I'd mention the Atari 5200 definitely has a form of scanline counter, which is the same chipset as the 400 / 800 computers debuted in 1979 - which is  the same release year as the Intellivision and original TI-99.

I've really come to love your videos and I get excited each time I see a new one.

I find these kind of videos absolutely fascinating, and yours in particular are extremely well done. Subbed.

Regarding Mode 3, there's a very recent SMS demo called "Multicolor Mars" that uses that mode. Funnily enough, it does not work on the SG-1000 because it takes advantage of the SMS's scanline counter and increased VRAM for some effects (in addition to the art being based around the SMS's weird legacy mode palette).

Interesting video! I learned some new things.
Mega Drive is a great machine!