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the_crayon_king

RGB/YPbPr Intellivision Thoughts

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1 hour ago, mr_me said:

What kind of TV are you using to test colours.  I found televisions from the late 1990s early 2000s look a lot different than those those from the 1970s and early 1980s.  I like IMBerzerk's brown, you don't want the hamburgers in burgertime to look too green.

Lol that's a hamburger ?! I thought it was a big ol pickle.

I thought the hamburger patties were coming later and we were just making pickle and lettuce sandwiches.

In hindsight that doesn't make a lot of sense.

 

All my TVs are early to late 90s.

Apart of the problem is blending you get though RF; I will cede that the color "brown" should probably be brown and not green. Despite how it looks on my TVs though RF. I have to use other people eyes to discern color correctness because I didn't grow up with this console.

 

I changed it to this:

https://i.imgur.com/jRh4euE.jpg

 

This is brown without the tinge of green in it 074 074 000; VS IMbezerk's 066 074 008
This is also an example where the khaki colored tan looks less good than the yellowish colored tan

 

 

 

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Olive drab or army drab is how some people describe intellivision brown.  It probably should have a bit of green.

 

Here's how an intellivision programmer at Mattel described all sixteen colours back in 1980.

Quote

BLACK: True.

BLUE: Not quite dark blue PC board; closer to '65 Cadillac than '66 Falcon; lapis lazuli.

RED: Red shirt red, much lighter than a rose; slightly purple?

TAN: Sandy, almost light brown.

DARK GREEN: Very dark - climbing-ivy dark, or rubber-tree dark.

GREEN: Same shade but lighter, perhaps grass green; touch of yellow.

YELLOW: Dark yellow - Afrika Korps yellow, definitely not marigold. Not quite amber.

WHITE: True.

GRAY: With a tinge of purple.

CYAN: Sick green-blue; institutional washroom green-blue.

ORANGE: Pale, closer to light red than to true Halloween orange.

BROWN: Very dark, the color of wet topsoil.

MAGENTA: Very bright, garish pink with a tinge of purple.

LIGHT BLUE: The color of the California sky looking up at 45 degrees. Perhaps a pastel color.

YELLOW-GREEN: The same shade [of green] again, but somewhat more faded. The grass of August? A true pastel green.

PURPLE: Dark violet Easter-egg dye purple

https://web.archive.org/web/20181219121059/http://www.intellivisionlives.com/media/newsletters/news030427.html

Edited by mr_me
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19 hours ago, mr_me said:

Olive drab or army drab is how some people describe intellivision brown.  It probably should have a bit of green.

 

Here's how an intellivision programmer at Mattel described all sixteen colours back in 1980.

https://web.archive.org/web/20181219121059/http://www.intellivisionlives.com/media/newsletters/news030427.html

So I converted those descriptions into colors but I can't say they match the palettes that are out there much.

Here is an example with IMBezerk's palette on top and the description colors on bottom:

https://i.imgur.com/lwHwGcu.png

 

The blacked out colors are ones I haven't done yet.

I got the colors by taking the things he is talking about and putting them through a color averager.

Or sometimes I took descriptions like "gray with a tinge of purple" to mean things like lavender gray.

 

I'm not sure what to do with this information really..

 

Imbezerk's purple isn't dark purple either; its more of a dark magenta.

 

"Sick green-blue" would be retro mint green I am pretty sure.

 

Afrika Korps yellow shows up a bit different in the show The Rat Patrol than any modern cognates for that color.

Still his description points to something in-between marigold and amber which is what I did.

 

The overall point being what are we considering as "accurate" when we talk about these colors?

These boards will be coming in a few days and I want to install them.

Edited by the_crayon_king

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10 minutes ago, Icelvlan said:

Are these the final boards?

I ordered 200; I really freaking hope so.

 

These will be here on the 23rd.

 

I will write the code against the three most popular palettes and just flash it accordingly.

That doesn't mean this board will have three palettes just that it can hold one of the three.

Three is just an arbitrary number btw. I just don't want to write/test more than that right now.

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I'm in for a few when they are ready! Really excited to try it out and can see if my OSSC likes it or not as well.

 

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As of now I have ordered many more parts needed to make 100 of these.

I have 5 or so finished. I ran out of CPLDs.

 

This final revision works in both a model 1 and model 2.

 

@-^CrossBow^-

If OSSC compatibility is important to you then you should wait to order until I have it confirmed as working.

This is the sync I have already : https://i.imgur.com/0tVRyFl.png

The three sync pulses you see inside of Vsync are input to the AY-3-8915 but are missing from it's RF outputs.

All I did was re-add those three pulses. I don't think this would actually be enough to fix anything.

 

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11 hours ago, the_crayon_king said:

@-^CrossBow^-

If OSSC compatibility is important to you then you should wait to order until I have it confirmed as working.

This is the sync I have already : https://i.imgur.com/0tVRyFl.png

The three sync pulses you see inside of Vsync are input to the AY-3-8915 but are missing from it's RF outputs.

All I did was re-add those three pulses. I don't think this would actually be enough to fix anything.

 

Understood,

 

while I've not actually tried it since I don't have cables on hand to do so, It might be possible in my case for the issues with the OSSC to 'corrected' by using SCART to BNC cables and connecting it to my extron to handle the upscale and video output. My extron outputs all video as a 640x480p scaled VGA ouput into my OSSC. From there I have the OSSC profile for the Extron set to 2x Line double which, my TV does seem to support just fine. It isn't something I've tested because I only have composite,s-video, and 2 component devices running through it currently, but it can do RGB as well. My actual RGB stuff just goes into a Bainridge 3 SCART switcher and then into the OSSC. But in my case I do have ways around this.

 

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@Icelvlan  You can use this board for O2 RGB:

https://easyeda.com/hotdog6394/magnavox-odyssey-2-rgb-unclked

This is a non-programmable thing and I made it open source.

It has expansion things in order to add YPbPr/Composite/S-Video.

I can sell some of those if you want.

 

The CPLD version of the O2 mod just needs validated again. It is one of those consoles with a clock that needed buffered. I haven't ordered the parts to buffer the clock yet. I don't know if there are any pros or cons to using the CPLD vs that other mod.

 

I will probably put up what I have by the end of the month. I will have pictures and stuff before then. So far its looking like 5 boards. There will be a few gaps in production until I can make a large batch. It is far less of a pain in the long term to do a larger batch than to do a few at a time and that is what I am gearing up for. I need to check a few more things on my end to make sure the P-P of the outputs analog RGB are in the right area. If not that will be another wrench in the gears. I mean I am pretty sure it is spot on (given the colors) but I need to actually measure it to make sure.

--------------

@-^CrossBow^-  I would wager something in your list of things might correct the sync.

--------------

The board will have a toggle for SOG (sync on green), a toggle for YPbPr, and a toggle for that one yellowish/tan color. Those are are labeled

Edited by the_crayon_king

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2 hours ago, Icelvlan said:

Can I create on OSH?

It is licensed under CC-BY-SA 3.0 so just follow the license requirements (or don't I'm not a cop). So yes, you can print on OSH. Just export the easyeda version's gerber then upload to OSH.

 

I have one of these installed in my personal O2 and ramble about it on this page:

https://atariage.com/forums/topic/266026-magnavox-odyssey-2-rgb-mod-anyone-care-to-try-this/

 

If you try it out and want to post results it would be best to post on that page.

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25 minutes ago, Icelvlan said:

Do they work with both OSSC and framemeister?

AFAIK everything works with the XRGB/framemeister.

I also do not know if that mod kit works with the OSSC as I still do not have one.

I will get an OSSC eventually but I was trying to hold out for the Pro one.

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Here are some pictures on the model 2:

Top View

Kit Wired

Bottom View

8 Pin Mini Din Install

 

That should give some idea of installation on that model.

The only alternative to some kind of weird mounting for the 8pin is to mount on the side of the console.

I rather install on the rear even if it requires cutting into the shell a bit.

 

There are 3 jumpers (for hard setting) and three through holes (for toggle switches).

SOG/SOG = Toggles/sets Sync on Green. You should know if you need this. (SOG off is default)

YPbPr/COL = Toggles/sets YPbPr on. (RGB on is default)

PALSEL/PAL = Toggles/sets the one variable color (changes tan to yellowish).(whiteish tan is default)

 

 

Notice the 0ohm jumpers where the 220-330uf caps would typically go. This is because in most cases I think people will have the caps inside of their cables.

I dunno if caps are even necessary in general if there isn't significant DC offset (which this thing does not have).

 

Let me know if you have questions/comments. Ill be thumbing around with the other Intellivisions I have.

 

(note) as to why the 8 pin mini din has an audio jack on either side; it's because I was going to use a 3.5mm audio jack and then couldn't find one. So I had to adapt given that the 8-pin was already drilled out. Typically, I would recommend you have audio on one side and the din on the other.

 

I would further recommend you cut away and flatten out the area where you make the din hole BEFORE installing the din. It doesn't have to be completely flat just either flush or lower than the 8pin din connector.

 

Installing YPbPr on the model 2 will reqire a lot more finesse as the only place to install is below the motherboard. If you mount too high/too low then your RCAs cannot thread on the rear.

If mounted too high your RCA cables cannot be inserted.

You really have to thread the needle to do the YPbPr mod. Or you can just do like me and cut an oval shape and cover your shame with a washer. https://i.imgur.com/Vb3XWxe.jpg

 

MOD KIT PAD NAME>> AY-3-8915 NAME>>  AY-3-8915 PIN NUMBER

2    >> V5   >> 4

3    >> V4   >> 5

5    >> V3   >> 6

6    >> V2   >> 7

7    >> V1   >> 8

5V  >> VCC >> 13

CLK >> CLK >> 15

GND can be taken from anywhere.

 

 

Edited by the_crayon_king

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7 minutes ago, Icelvlan said:

Is it possible to implement TTL sync instead of 75ohm?

This should be both; refer to https://tinyurl.com/y6asffcz

If there is no pulldown resistor on the end then the sync signal is TTL 0-3.3V (well within TTL)

If there is a 75 ohm pulldown then you will have 0-900mv (well enough for normal sync).

 

Unless you need some sort of exacting voltage sync should be fine (as far as voltage).

Edited by the_crayon_king

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2 minutes ago, Icelvlan said:

I'd be using a Genesis 2 cable, I thought it needed to be 5V?

 

TTL is 0 to 0.8 for low and 2-5V for high. 3.3V is much above 2V.

The pinout for genesis 2 is different than the 8-pin mini din.

This pinout I am using is the same as the NES RGB/XRGB

Retro Gaming Cables Limited on Twitter: "We have just received our new 8  pin min DIN mould, so we can male SCART cables for the Tim Worthington NES  RGB mod… "

It should use the same exact cable as the NES RGB mod except two RCAs for audio instead of a 3.5MM audio jack.

The kit I have put together has a breakout for MD-80SV (8 pin mini din).

 

If you have your own genesis style connector you will have to manually solder to the pins or something IDK.

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Easy to do I solder the connector into a breakout board, but I'll likely have to remove the resistors and caps on RGB lines since they are in the cable correct?

Edited by Icelvlan

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11 minutes ago, Icelvlan said:

Easy to do I solder the connector into a breakout board, but I'll likely have to remove the resistors and caps on RGB lines since they are in the cable correct?

Your RGB lines inside of your cable should not have resistors in them. I don't know why they would. Except maybe sync,. but you want TTL sync so if there is a resistor on sync it shouldn't hurt anything unless it is terminated.

People that make RGB cables really freaking need to stop putting resistors in their cables for sync. I have to calculate against an extra 330ohms in series because they keep doing that crap. It's the reason I am using 900mv instead of 300ish.

TLDR don't remove anything off the mod kit.

 

I have places to solder capacitors if they are needed and NOT in your cable.

If you have caps in your cable then you DO NOT want caps on the mod board.

Two caps in series is bad.

Using the capacitor spots on the mod board is sort of a last resort. In most cases those spots will be jumped with a 0ohm.
 

In general, unless someone tells me they need capacitors I am going to leave them off. I will have to do some research to see if they have some sort of use besides dealing with DC offset. The cables people have shouldn't need altered either.

 

Edited by the_crayon_king

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It looks like all the big manufacturers are doing it as they are made for consoles. Edited. I misread your post. I think they are 220uf and 75ohm on RGB lines and 220uf and 470ohm on Csync line to allow into framemeister. Not 100% on values.

Edited by Icelvlan

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31 minutes ago, Icelvlan said:

It looks like all the big manufacturers are doing it as they are made for the consoles. I don't see a reason to reinvent outside that? I think they are 220uf and 75ohm on RGB lines and 220uf and 470ohm on Csync line to allow into framemeister. Not 100% on values.

220uf should be the low end of caps; the benefit of having caps in the cable is they can use better ones. SMD caps in the mod kits are like 50cents a pop. Putting caps in the cable does make sense; but because cables exists with/without caps I have to create boards against both possibilities.

 

This is more to the point of when RGB and sync are buffered with an op-amp.

I have to make it so 75ohm terminated is not too high when there is only a 75 ohm resistor and not too low when in series with the highest value they use. If they all used the same value it would be fine. I mean I do understand why they use resistors (over voltage when connecting TTL to 75ohm termination). I just wish they would pick one.

 

They are doing it now is the thing. The cables I have from 5 years ago do not have resistors in the lines; so like the cap issue before I have to make against both possibilities.

Edited by the_crayon_king

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Well as an example pretty much all of the Genesis/Megadrive 2 style RGB SCART cables have the resistors and caps in the SCART housing or use a PCB in the housing with SMD resistors and caps. Because of this, is why when using a Genesis/Megadrive 2 style RGB cable with TMS-RGB, you have to remove he small 75R off the output lines on the TMS-RGB itself and bridge the pads or install 0R in their place. If you don't it will still work, but the overall output is darker than it should be. The +5 is usually needed for when people want to use Rad2X cables or SCART switchers that need the +5 to to be told the signal is present to switch over. That is what the +5 is needed for on mine in most cases but yeah HDRetrovision cables and Rad2X cables require the +5 to power their internal components in the cable.

 

So I guess ultimately, is to just wire it up to match the pinouts of a Megadrive2 AV cable and see what you get.

 

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