v0.40.0-preview

[JetSetIlly]

What a mess! Also color 14 is now "gold".

Oh yes! I didn't notice that.

I'm not sure what to make of it. I'll have to meditate on this new information.

[alex_79]

BTW, the single chip "JAN" Atari Junior has no way to adjust the color phase. There's no pot on the board.

The schematic of the "Atari 2100" (prototype of the Jr.) shows a 48 pin Chip and there's no "Color Adjust" or similar pin like in the TIA (edit: the chip pinout is in the Jan programming guide too). The actual single chip Junior that was produced has a 64 pin chip, and no schematic or official doc exist for it. But the additional pins compared to the prototype pinout are either connected to GND or left floating, so the phase is determined by the chip itself here too.

So, maybe that could be the reference for the "intended" palette?

[JetSetIlly]

So, maybe that could be the reference for the "intended" palette?

Yes! That would be brilliant.

Do we know anyone with a single chip 2600?

[Thomas Jentzsch]

We should ask at the thread in AtariAge, no?

[JetSetIlly]

New blog post summarising what I know and think about this problem.

https://jetsetilly.github.io/Gopher2600-Blog/posts/the-ntsc-colour-problem/

[Thomas Jentzsch]

Nice write.

[SpiceWare]

Well done.  Spotted a couple typos:

Code Select Expand

lum = col & 0xfe
should be:

Code Select Expand

lum = col & 0x0e
and this:

Code Select Expand

A special work about Janice.
should be:

Code Select Expand

A special word about Janice.

[JetSetIlly]

Well done.  Spotted a couple typos:

Updated. Thanks

[JetSetIlly]

New blog post summarising what I know and think about this problem.

https://jetsetilly.github.io/Gopher2600-Blog/posts/the-ntsc-colour-problem/

Follow up article: https://jetsetilly.github.io/Gopher2600-Blog/posts/ntsc-colour-in-vintage-games/

Thomas: includes some more thoughts about a 2600 container file format that we've talked about previously.

[Thomas Jentzsch]

Your findings about the different hues are interesting. I suppose the developers had configured their TVs quite badly. Without noticing! But I don't think we should define color values per game, because I doubt any user would have adjusted these parameters per game back then.

Therefore people would only adjust the emulator color settings once to make them look like how they remember.

[JetSetIlly]

Your findings about the different hues are interesting. I suppose the developers had configured their TVs quite badly. Without noticing! But I don't think we should define color values per game, because I doubt any user would have adjusted these parameters per game back then.

Therefore people would only adjust the emulator color settings once to make them look like how they remember.

Hmm. That's a fair point.

However, I still think there's merit in making a note of what the optimal setting is for a game. I think it would be nice for emulators to give the option of automatically setting the hue/phase as required for the game.

[Thomas Jentzsch]

I don't know. There is a risk that this could be abused and a game would only look OK in an emulator. Also PAL conversions would become problematic, since the mappings would become very random.

[JetSetIlly]

I don't know. There is a risk that this could be abused and a game would only look OK in an emulator.

Yes. I agree that is a concern for new games. It's open to abuse for sure.

I think a compromise is for the emulator to optionally save hue settings for each ROM. So it's something the user consciously does for any game that needs it. But once it's set for the ROM it doesn't have to be done again.

Also PAL conversions would become problematic, since the mappings would become very random.

That would depend on how the conversion is done I think.

[Thomas Jentzsch]

Sorry, I am not convinced. Looks a bit like faking reality to me.

[JetSetIlly]

?? Which bit is not realistic? Saving the hue setting per game as per the user wishes, is faking reality?