VGA to RGB SCART UK?

[steddyman]

Does anyone know where I can buy a MiSTer RGB to SCART cable in the UK?

Thanks

[Brettster]

I ended up making my own, you can find some on Ebay but they are not cheap for the ones that work on MiSTer or the cheap ones are not compatible!

[CDR_Jameson]

I have ordered this one here; http://amigakit.amiga.store/product_inf ... cts_id=919 but I am still waiting for the cable to arrive so I can't vouch for it since I have yet to test it.

[steddyman]

Great. Thanks. I've just ordered one from amigakit also.

[akeley]

They say it's ONLY for "Minimig board" but I have a MiST cable and it works fine.

[steddyman]

I'm sure it will be fine. They are both VGA at the end of the day.

[CDR_Jameson]

The cable arrived and works flawless with my setup. Recommended for those in the UK or EU.

[lastninjaju]

Would this work using the direct video method? i.e. HDMI to VGA converter to vga end of cable to scart tv ? Or does it only work using an I/O board?

[glopglop]

I just received one of the AmigaKit cables.

I'm using the Direct Video HDMI => VGA => SCART solution.

I have a slight green tinge on my 14" Sony telly and on a white screen you can see these green and purple areas.

IMG_20200826_165223.jpg (1.13 MiB) Viewed 13931 times

IMG_20200826_165223.jpg (1.13 MiB) Viewed 13931 times

I'm thinking I may need to add the 470 ohm resistor as described here : https://github.com/MiSTer-devel/Main_Mi ... gb-signals

The cable I have also has a shared ground for the red/blue/green grounds, I assume this is fine and the grounds don't need to be separate.

Screen looks great when I connect my (real) C64 via SCART.

Any ideas?

[glopglop]

For anyone else, I got mine sorted, looks great now.

So the TV is a Sony Trinitron 14", not sure if that's related but I have read some mention of Sony's being a bit picky there.

In summary I bought the AmigaKit MiST cable, but had issues with off colour as above.

Adding a 1000 ohm resistor onto the wire between pin 13 on the vga side and pin 20 on the SCART side resolved it, always hard to tell from photos of CRTs but it does look fantastic now, if anything the colours might be too good, I can turn it down in the settings but I'm wondering if maybe some resistance is required on the rgb lines.

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IMG_20200829_094456.jpg (244.48 KiB) Viewed 13906 times

Anyway after adding the 1kohm resistor I pulled that out and added a 2k potentiometer, it does look great but since the resistance seems important on the sync line it's nice to have an option to tune it just in case.

[akeley]

Yes, this is the same problem as described here: viewtopic.php?f=33&t=614

I'm using my other Trinitron atm, which is not affected by that, but would like to be able to use MiSTer on my other ones too. Any chance you could draw a simple schematic describing these modifications? Or at least do a simple bullet point write up?

Reason I ask is that I have a friend who is handy with electronics and can do it for me, but I need to provide a clear explanation.

PS: I don't think the 470 Ohm resistor has anything to do with colours, but is supposed to be a voltage protection. I would like to add it to, do you think it can go along with these other changes?

[supermattkelly]

Sorry if this is a bit off the topic, but would this work with an NTSC CRT that has been RGB modded with a SCART socket?

[glopglop]

Yes, this is the same problem as described here: viewtopic.php?f=33&t=614

I'm using my other Trinitron atm, which is not affected by that, but would like to be able to use MiSTer on my other ones too. Any chance you could draw a simple schematic describing these modifications? Or at least do a simple bullet point write up?

Reason I ask is that I have a friend who is handy with electronics and can do it for me, but I need to provide a clear explanation.

PS: I don't think the 470 Ohm resistor has anything to do with colours, but is supposed to be a voltage protection. I would like to add it to, do you think it can go along with these other changes?

Sorry only just seen this.

I wired a variable resistor onto the sync line, thinking I might need 1k ohms on it based I think on this : http://www.geocities.ws/podernixie/htpc/cables-en.html (the cyan line)

The resistor seems to be set at 972ohms at the moment.

IMG_20201115_120258.jpg (722.77 KiB) Viewed 13460 times

That got it working as above.

But to be honest though I'm not sure it's fully correct. It does seem to work directly to the TV, but I added a SCART switcher in between the TV and the Mister but it ends up with the screen being super dark and clearly not correct. The SCART switcher seems to work wine with other devices.

[glopglop]

Just to update, had a muck around with this today on a breadboard, not using the AmigaKit cable, essentially this seems to work fine for me on the Sony telly directly, through the SCART box and also via an OSSC to a HDMI telly.

Essentially this, which you can see in various places, but with the addition of a 1k resistor on the composite sync line VGA pin 13 => SCART pin 20 :

UiaUsG5.png (41.19 KiB) Viewed 8329 times

The little blue box on the breadboard is the variable resistor.

IMG_20201115_175418.jpg (477.94 KiB) Viewed 13434 times

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IMG_20201115_175604.jpg (334.34 KiB) Viewed 13434 times

IMG_20201115_175825.jpg (444.8 KiB) Viewed 13434 times

IMG_20201115_175536.jpg (445.64 KiB) Viewed 13434 times

[akeley]

Right. Thanks for the schematic. It seems I will have to do it myself eventually, though it looks terrifying

I'm still curious if it's better to use a potentiometer resistor, so you can adjust it on the fly? And if you still need this 470Ihm resistor, as voltage protection (the perennial questions: viewtopic.php?p=12712#p12712)

[metal_slugger]

Hi, I have the analogue I/O board 6.1 on my MiSTer. Is anyone selling a cable I can use from this to my RGB Sony Trinitron (60hz) yet, that has all the modifications for best picture already done?
Thanks

[metalfacemark]

metal slugger - send me your address and ill send you one, i have a spare one you can have mate.

[metal_slugger]

metal slugger - send me your address and ill send you one, i have a spare one you can have mate.

That's amazing man. I PM'd you. I never sent a PM in this site before, hopefully you got it ok

[Soiryu]

Just to update, had a muck around with this today on a breadboard, not using the AmigaKit cable, essentially this seems to work fine for me on the Sony telly directly, through the SCART box and also via an OSSC to a HDMI telly.

Essentially this, which you can see in various places, but with the addition of a 1k resistor on the composite sync line VGA pin 13 => SCART pin 20

The little blue box on the breadboard is the variable resistor.

I found your schematic looking to make one, I'm going to try this schematic as soon as I have a little time, these cables seem to work fine.