RGB Modded Intellivision with OSSC

[+KylJoy]

I tried the settings suggested in the thread HERE to no avail.

 

As far as the scope, it is a Rigol DS1054Z. Low cost for what you get.

[First Spear]

Was a resolution found to this issue? I have a French SCART inty and a new OSSC (v.85 firmware) and it says "no sync" when the Intellivision is connected. I'm not sure what can be tweaked, all ideas appreciated.

 

Thanks!

 

[+grips03]

Was told it will never work due to hardware being used on OSSC by marqs.

[First Spear]

On 12/25/2019 at 5:35 PM, grips03 said:

Was told it will never work due to hardware being used on OSSC by marqs.

Can you explain a bit more about "why"? I (obviously) don't understand. I saw something in the OSSC FB group that said to change the input frequency, still trying to figure out how to actually do that, but if it's futile I'd appreciate direction. I'm lost!

 

Thanks.

 

[First Spear]

On 12/25/2019 at 5:35 PM, grips03 said:

Was told it will never work due to hardware being used on OSSC by marqs.

I was looking at http://junkerhq.net/xrgb/index.php?title=Optimal_timings and trying to find any related numbers on the Intellivision Scart version instruction.pdf but so far, no clue.

[+grips03]

I tried the Intv RGB kit from Fred K, Intv RGB kit from Bruce A, and the Intv RGB kit from Emerson, none of them worked with OSSC.  All had sync issue.

 

They all work with this cheap RGB to HDMI adapter from eBay and to Sony PVM.  Perhaps the French one will work with OSSC, but I don't have one to try.

[carlsson]

I tried to understand the screenshots @KylJoy posted from his digital oscilloscope. Does mU refer to millivolts derived from that U usually is used for unterschied (voltage)? In his readings the sync signal varied from 80 to 500 mU while the NTSC test signal was up to 16 times stronger. What would the same readings be from e.g. the Sega Master System?

 

I'm simply wondering if some or all of the signals from the RGB mod are too weak, and while the Framemeister xRGB-Mini can pick those up and produce an image, the OSSC can't. But that is just a wild guess, and if three different RGB kits generate the same results, it would indicate that everyone are missing out on some voltage detail or the OSSC is particularly picky about the input signals. I feel like I'm barking up the wrong tree here, but not sure what I'm seeing or understanding.

[emmanuelf]

On all schematics I saw or by picture guessing, there is no proper video output buffer ensuring proper scart levels on double terminated 75ohm link.

On the OSSC, you should use sync on green to go trough the input buffer circuit as the video signal. Otherwise you go directly  to the TVP video dac.

The TVP is perhaps more picky or not properly configured to process correctly the border line sync signal.

 

Measurement with the scope should be done with the output of the RGB mod connected to the OSSC.

[First Spear]

6 hours ago, emmanuelf said:

On all schematics I saw or by picture guessing, there is no proper video output buffer ensuring proper scart levels on double terminated 75ohm link.

On the OSSC, you should use sync on green to go trough the input buffer circuit as the video signal. Otherwise you go directly  to the TVP video dac.

The TVP is perhaps more picky or not properly configured to process correctly the border line sync signal.

 

Measurement with the scope should be done with the output of the RGB mod connected to the OSSC.

The PDF I saw on the Intellivision French SCART output showed a dedicated pin for sync, I think it was 20. I interpreted that as "RGBS" for the OSSC. Are you saying that instead it should be "RGsB (sync on green)" instead? Very confused I am.

 

Thanks.

 

[emmanuelf]

Not exactly.

As designed, I think that the OSSC will be less picky with "border line compliant" sync signal with sync on green sync signal.

I don't have an inty scart version, too rare even if I'm in France. So I don't know how the sync signal is generated in them.

Yes, on the "normal" scart standard, there is a dedicated pin for sync, but OSSC accept sync on green too.

 

Combining the sync with the green and configuring the OSSC accordingly worth a try.

[ChildOfCv]

On 12/30/2019 at 5:04 PM, carlsson said:

I tried to understand the screenshots @KylJoy posted from his digital oscilloscope. Does mU refer to millivolts derived from that U usually is used for unterschied (voltage)? In his readings the sync signal varied from 80 to 500 mU while the NTSC test signal was up to 16 times stronger. What would the same readings be from e.g. the Sega Master System?

 

I'm simply wondering if some or all of the signals from the RGB mod are too weak, and while the Framemeister xRGB-Mini can pick those up and produce an image, the OSSC can't. But that is just a wild guess, and if three different RGB kits generate the same results, it would indicate that everyone are missing out on some voltage detail or the OSSC is particularly picky about the input signals. I feel like I'm barking up the wrong tree here, but not sure what I'm seeing or understanding.

I think Rigol just has a somewhat peculiar font.  Their u's have a vertical line on the right side, so I think those are V's in the measurements.

 

Anyway, the sync output is definitely lazy.  It shows one pulse for each visible frame, nothing during vertical blanking, one large pulse for vertical sync, and again nothing for vertical blanking.  Is one of the chips on that mod board supposed to be generating the sync signal?

 

Actually, maybe this is what composite sync is supposed to look like when separated out.  It at least says when all the visible lines start, and when vertical sync happens.

Edited January 1, 2020 by ChildOfCv

[ChildOfCv]

Looking at the OSSC schematic, it takes sync from SCART pin 20, red from 15, green from 11, and blue from 7.  So the first thing is to see what pin your cable connects each board output to.  The next question is, does it provide a sync on the green output?  Or only on the S output?

 

Finally, what mode is the OSSC in?  The video processor chip that they use allows different input pins for R, G, B, and sync.  It appears that if you intend to use the separate sync, you need sync on input 2 and everything else on input 1.  If you have the optional remote, use button 1 to set the proper mode.  If you have a remote for an old TV that uses the NEC protocol, you can also make the OSSC learn to use it.

[First Spear]

16 hours ago, ChildOfCv said:

Looking at the OSSC schematic, it takes sync from SCART pin 20, red from 15, green from 11, and blue from 7.  So the first thing is to see what pin your cable connects each board output to.  The next question is, does it provide a sync on the green output?  Or only on the S output?

 

Finally, what mode is the OSSC in?  The video processor chip that they use allows different input pins for R, G, B, and sync.  It appears that if you intend to use the separate sync, you need sync on input 2 and everything else on input 1.  If you have the optional remote, use button 1 to set the proper mode.  If you have a remote for an old TV that uses the NEC protocol, you can also make the OSSC learn to use it.

 

This image is a series of images that flash quickly when the OSSC is set to RGsB, one moment after I turn the Intellivision on. The red led stays lit, does not flicker.

 

What kind of (input) settings could I try, based on what the OSSC briefly showed? Is there some kind of KHz setting somewhere I should change?

 

These are steps I take to reproduce this:
1. Intellivision is off
2. OSSC is off
3. Turn OSSC on (see green light and grey test pattern on TV with OSSC text)
4. Turn on Intellivision
5. Use remote to change OSSC to RGsB
6. LCD on OSSC quickly flicks-cycles through several screens (maybe input KHz?)
7. OSSC red light shows on the unit
8. TV shows "NO HDMI signal"
9. OSSC LCD shows "AV1: RGsB NO SYNC"

Thanks.

 

 

 

 

 

 

[ChildOfCv]

Don't use RGsB.  Use RGBS.  According to the docs on their WIKI, that's button 1 instead of 2.

[First Spear]

1 hour ago, ChildOfCv said:

Don't use RGsB.  Use RGBS.  According to the docs on their WIKI, that's button 1 instead of 2.

I was trying RGBS and only got message on the LCD "NO SYNC" but when I tried "RGsB" I got the red light of no sync and the OSSC display stopped outputting. So strange. OK, I'l go back to trying RGBS.

[ChildOfCv]

4 hours ago, First Spear said:

I was trying RGBS and only got message on the LCD "NO SYNC" but when I tried "RGsB" I got the red light of no sync and the OSSC display stopped outputting. So strange. OK, I'l go back to trying RGBS.

Hmmm.  Well, the difference is that RGBS is separate sync, which it sounds like the RetroRGB does.  RGsB means that sync is combined with green.

 

So, next is to make sure that the appropriate pins connect all the way to the RetroRGB board.  You have your diagram above, though you only care about R, G, B, Sync, and the grounds.

 

I guess the VSYNC threshold is okay.  Your VSYNC shown in the output is about 200uS, which is definitely more than the 10uS default threshold.  Of course, it's unknown whether the signal processing chip uses it or ignores it for being too long.

[First Spear]

On 1/2/2020 at 1:09 AM, ChildOfCv said:

Hmmm.  Well, the difference is that RGBS is separate sync, which it sounds like the RetroRGB does.  RGsB means that sync is combined with green.

 

So, next is to make sure that the appropriate pins connect all the way to the RetroRGB board.  You have your diagram above, though you only care about R, G, B, Sync, and the grounds.

 

I guess the VSYNC threshold is okay.  Your VSYNC shown in the output is about 200uS, which is definitely more than the 10uS default threshold.  Of course, it's unknown whether the signal processing chip uses it or ignores it for being too long.

I will see what info I can find about things bring wired "all the way" in the OSSC.

 

I found this web page about different France Intellivision versions, but don't actually know what I am reading.

 

https://www.gamopat-forum.com/t89204-les-differentes-versions-d-intellivision

[ChildOfCv]

Well I'd assume that the OSSC's internal connections are correct, and begin with the SCART side of the adapter cable, still plugged into the INTV.  Then make sure that the RetroRGB outputs connect to the appropriate pins on the SCART connector.