RGBtoHDMI to CPC Plus

Beaps · 13:54, 21 March 22

Hi All

I am trying to run my CPC Plus using RGBtoHDMI but I cannot get it sync, any ideas, maybe a work around?

Ta
B

Bryce · 15:22, 21 March 22

If we knew which RGB to HDMI converter you are using that might help.

Bryce.

Beaps · 15:57, 21 March 22

Sorry haha its this one

pelrun · 06:14, 22 March 22

Quote from: Bryce on 15:22, 21 March 22If we knew which RGB to HDMI converter you are using that might help.

They already did - *the* RGBtoHDMI, not *a* one. https://github.com/hoglet67/RGBtoHDMI

@Beaps, did you go through the troubleshooting section on the RGBtoHDMI wiki?

Beaps · 08:00, 22 March 22

Sorry I'm confused, what's The RGBtoHDMI?

Yeah I looked through the troubleshooting and no mention of the CPC Plus machines.

eto · 08:16, 22 March 22

Quote from: Beaps on 08:00, 22 March 22Sorry I'm confused, what's The RGBtoHDMI?

Yeah I looked through the troubleshooting and no mention of the CPC Plus machines.

"a" RGB to HDMI would be any type of device that converts RGB to HDMI, also a SCART to HDMI connector would be such a device. The device you have has a title/name of "RGBtoHDMI". That's why it's "THE" RGBtoHDMI (a device of the type RGB to HDMI with the name "RGBtoHDMI").

CPC/Plus machines have a 50Hz output like many other machines. You don't need to look for specific sections about the Amstrad, but anything that is similar to what you experience. Did you e.g. check the very first section of this page?
https://github.com/hoglet67/RGBtoHDMI/wiki/Troubleshooting

Beaps · 09:41, 22 March 22

No help then, never mind I'll either work it out myself or leave it. Thanks

Bryce · 09:53, 22 March 22

Quote from: pelrun on 06:14, 22 March 22
Quote from: Bryce on 15:22, 21 March 22If we knew which RGB to HDMI converter you are using that might help.

They already did - *the* RGBtoHDMI, not *a* one. https://github.com/hoglet67/RGBtoHDMI

@Beaps, did you go through the troubleshooting section on the RGBtoHDMI wiki?

Then they picked a shitty name for it. How is anyone supposed to know it's that specific one. It's like calling your bicycle design "Bicycle".

Bryce.

eto · 10:16, 22 March 22

Quote from: Beaps on 09:41, 22 March 22No help then, never mind I'll either work it out myself or leave it. Thanks

I guess nobody has tried out yet the RGBtoHDMI. Afaik @Piotr did make some of these converters. But he wasn't online for quite some time. You might find him on Facebook in one of the Amstrad groups and check if he has some ideas.

Btw: if you manage to get it to work, could you test Ghosts'n'Goblins, Relentless and the Batman Demo, if they are working correctly? My GBS8200 fails to display them properly and even not all LCD TVs with Scart do properly sync everything.

Beaps · 10:39, 22 March 22

I've already asked Piotr via FB and he don't know either. I'm thinking as it's green on sync I have to split off the sync using a sync stripper to get it to work.

pelrun · 12:45, 22 March 22

It's not sync-on-green! Composite sync is on it's own pin.

eto · 12:50, 22 March 22

Quote from: Beaps on 10:39, 22 March 22I've already asked Piotr via FB and he don't know either. I'm thinking as it's green on sync I have to split off the sync using a sync stripper to get it to work.

The Amstrad has vsync and hsync combined (csync) on one pin and luminance on another. Luminance is kind of a composite video, but not with colours but greyscale (brightness) only. There is no sync on green.

Are you using the Analogue board? The analogue board for the RGBtoHDMI is supposed to work with the Amstrad CPC and accepts the CSync directly: https://github.com/hoglet67/RGBtoHDMI/wiki/Cables#amstrad-cpc-analog-rgb

Keep in mind that the pinout of the PLUS monitor connection is different to the CPC. btw: that board is not supposed to work for the 4096 colours of the Plus. Seems like 12bit colour boards require you to connect them to the pins of the chips inside the computer directly, not to analogue output.

And maybe someone from this thread can also help:
https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/amiga-hdmi-with-a-raspberry-pi!-(rgbtohdmi)-and-cpc/

And last but not least: have you confirmed that the RGBtoHDMI properly works? Maybe on a different computer? Or just that the menu appears?

Beaps · 13:46, 22 March 22

Yeah it works fine with my 464 regular machine. I have made another connector for the plus (as like you say it has more pins). I can see the image but it has no sync. Even the RGBtoHDMI menu says no sync so its constantly rolling. Also yes I am using the anologue output as mentioned.

eto · 15:24, 22 March 22

Quote from: Beaps on 13:46, 22 March 22Yeah it works fine with my 464 regular machine. I have made another connector for the plus (as like you say it has more pins). I can see the image but it has no sync. Even the RGBtoHDMI menu says no sync so its constantly rolling. Also yes I am using the anologue output as mentioned.

Ok, then it's really surprising. I have a Plus, CPC 6128 and I had a 464 too. Whatever I connected to them, it behaved identically. CRTs/LCDs/GBS 8200 - no difference.

But to be honest, what happened to me almost every single time is, that I mixed up the pins - I always get confused which side is which pin. Just to be sure and not miss maybe the easiest fix: Did you verify you have connected pin 1 of the Plus to sync and that it's definitely properly connected?

https://cdn.retrorgb.com/wp-content/uploads/2019/09/cpc-vs-cpc-plus.png

Beaps · 20:00, 22 March 22

OK..... I've sussed it

I took the device out the case and looked at the small print on the board. Pin 1 was different than all the pics I've seen. I re soldered everything and bingo!

Thanks everyone for there input

SerErris · 14:27, 25 March 22

Do you have by chance pictures to share? That would be helpful to understand the issue and learn from it.

Mine was a bad solderjob, that kept it crashing ... (some pictures in another thread).

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RGBtoHDMI to CPC Plus