UPDATES
- The PAL / NTSC Section is somewhat lacking and a bit inaccurate. See the many liked comments below for more details.
- Many games were specifically coded for PAL, mostly to fix music timing (thanks @Strobo)
- Pattern tables contain 4KB of data not 64KB of data. I forgot to divide by 8 when calculating (thanks @HughGenuts)

I've been in the NES dev community since 1997, have written several emulators and know quite a bit about the system. This channel is legit - good info clearly presented. We'll done!

5:15 The map is correct, but the description is wrong. You see, strictly, PAL and NTSC refer only to the color encodings, not the whole systems. After all, analog TV is a monochrome signal first, plus a color subcarrier. So it's more proper to say the US used System M (525-line, 60i) with NTSC color on top, and most of Europe used System B (625-line, 50i) with PAL color on top.
And then Brazil used this funky thing called PAL-M, which was System M with PAL color.

The whole PAL/NTSC thing was a nightmare. Thank the Maker the world eventually settled on a single 2K/4K standard since then! Still, even though people in PAL regions lost out big-time with videogames they arguably won by the same degree with movies, with a noticeably higher SD resolution (625 vs 525 lines) and perfectly smooth motion, albeit with an imperceptible (4%) speed increase.

I'm really glad (and grateful) that you took the time and energy to produce this video, despite the fact that there are already many videos (among other documents) about the same topic. I know some creators have the attitude that you shouldn't do videos on things other channels have already covered. At least sometimes they do. But I'm glad that wasn't the case with this video. I never believed in that philosophy because even if I've seen other videos on NES graphics before, which I have, it's such a complicated and comprehensive subject that there's no way a 20, 30 or even 40 minute video could give you the full picture (sorry for the pun). Even if they did, there's no way a person could memorize everything in it. So it's always great to have multiple resources to consult on the same subject so you can get the same story told from a different perspective, so to speak. Plus that really helps with understanding the material intuitively, as well. If there's something technical in a video or document I don't understand, it always helps a lot to be able to have it explained differently.

tl;dr you have an amazing channel that's not afraid to take chances by covering topics others already have. And it's paid off in spades! Thank you for sharing your passion with us.

Technically there were mechanical tvs before crts but they were so impractical and uncommon that I wouldn’t argue with anyone who wanted to not count them. So I’ll let it slide.

The pattern tables don't each have 64 kilobytes of memory. Each pattern table has 256 tiles, each 8x8 pixels; that's 16384 pixels with 2 bit color depth, or 32768 bits in one pattern table. That's 4096 bytes, or 4 kilobytes.

SECAM was partially compatible with PAL, but produced a B&W image when presented with a PAL signal. So these of us growing up in SECAM regions generally were stuck with playing NES (or its clones) without color until multisystem TVs that supported both PAL and SECAM color became common. It wasn't until several years after I first played SMB that I learned that Mario's overalls are red on the NES.

SECAM NES did actually exist, but it was a pirated clone. Those were popular in ex-USSR in the early 90s. That particular SECAM edition was named Dendy SECAM Classic, if I'm not mistaken, and it was released in 1992. It was a first Russian NES bootleg clone. Subsequent bootleg models of Dendy were PAL only because of two factors, I think. First, multi-system TV sets became much more common by 1994 already. People even modded their old Soviet SECAM-only TVs by soldering PAL decoder. And second, it seems like Dendy SECAM was a failure from a technical POV, lacking reliable color output.

Making my first NES game, after a week of study and watching your videos, i have managed to draw a heart sprite to the screen. I already had respect for devs of the time, but experiencing it first hand is really starting to put it all into perspective, just how incredible these developers were.

Brazil uaed PAL-M that is actually 60Hz, because our electric grid originally came from US, but we use Europe standards more. So it is the best of both words, true colors but faster refresh. People nowadays convert Atari 2600 to this format to have better colors in emulators.

Its impressive how an image now is heavier than 2 or 4 nes gamed

What's kind of fascinating is that the nametable (32x30 tiles), is 960 bytes. The attribute table is 64 bytes. 960 + 64 = 1024 bytes. Exactly one kilobyte. They did not have a single bit to spare.

If this math was just a single byte off, you would probably have lost either an entire row or column on the screen as there's no way to simplify the attribute table.

Or the two nametables would be different sizes but that would just overly complicate things.

Gold

Very good stuff. I only ever made one commercial SNES game (not NES) but found it very enjoyable and this brings back memories. Most of my games were Amiga in 68000. Thanks for the great videos.

I maybe 43, but PPU makes me giggle.

1:51 count the tiles left to right on the top, and notice the blank one is the 37th tile, exactly the same as in SMB, so that blank tile is the 37th for the 36th world- a thing Wikipedia refuses to admit.

There was a day back in the 80s that I first saw a game cartridge inserted into a Nintendo the lid was closed and the power button was pressed and the game worked. Little did we know but this was not magic but people have figured this all out before we even had a chance to try it. We were spoiled rotten and things have gotten better ever since.

Im a software pro and this mem tables description makes so much sense to someone who also did some assembly programming on 8085 in College. Having played Nintendo games back in the 90s as a school kid, this is like life going full circles. You played the game as a kid and now you know how that game was made. And now it encourages someone like me  to actually fiddle with instruction sets on emulators.. Thanks much

NES that were sold in France were PAL versions. TV using the SECAM standards were also compatible with PAL. They were usually described as "PAL/SECAM" TV sets.