Oric 1 with messy video problem

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AmintaOric
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Oric 1 with messy video problem

Post by AmintaOric » Sat Sep 14, 2019 1:20 am

Hi all!

Here you can see the video of the messy problem of my Oric 1: https://share.icloud.com/photos/0abKtGr ... zjF0A#Casa (click on the thumbnail on the bottom of the page to play it).

As you can see, I get a "negative video" with no colors and, moreover, I can see it only if, together with the s-video to scart cable, I'm keeping attached also the RF cable! To see the boot screen I have also to set to maximum the brightness...

I've already changed the ULA but the result is the same...


Any hint?

Thanks in advance!

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kenneth
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Re: Oric 1 with messy video problem

Post by kenneth » Sat Sep 14, 2019 3:18 am

The ula seems ok
The wire is not a converter, the video output is a rgb signal. The tv set might receive the rf signal only because the switch signal is not connected to a 12v psu.

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Dbug
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Re: Oric 1 with messy video problem

Post by Dbug » Sat Sep 14, 2019 6:48 am

Generally speaking, the antenna/aerial output only works (unmodified) with British TVs.
The recommended way to get a good picture with the right colors is to use the RGB output connector.

If you have something like a Commodore Amiga monitor, you can just do a pin to pin connection and it will work, for TVs you should get yourself one of the Retroshack oric scart cables.

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kaydav
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Re: Oric 1 with messy video problem

Post by kaydav » Sat Sep 14, 2019 7:33 am

Dbug wrote:
Sat Sep 14, 2019 6:48 am
If you have something like a Commodore Amiga monitor, you can just do a pin to pin connection and it will work, for TVs you should get yourself one of the Retroshack oric scart cables.
I can speak for the Retroshack RGB-to-SCART cables. They have them on eBay. I just bought one for my Oric because my RF output was faulty, and the display is streets better with the new cable.

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Chema
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Re: Oric 1 with messy video problem

Post by Chema » Sat Sep 14, 2019 9:17 am

Hmmm... not sure about your configuration. The svideo is not compatible with RGB. In the SCART you can have both; maybe you are probably using the wrong signal.

I'd say you cannot use just an svideo to SCART converter, you need to use a TV that can input RGB. Most TVs with SCART can, although most also need voltage on one pin to change to RGB mode or you get no picture.

AmintaOric
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Re: Oric 1 with messy video problem

Post by AmintaOric » Sat Sep 14, 2019 11:33 am

Hi all!

First, many thanks for your answers and help!

To explain myself further: I connect the Oric 1 to my Philips CM8833 via a 5 Pin to Scart Cable that you can see in the pictures linked below but I can't get a correct image; if a switch the monitor to RGB, I get no image at all; strangely, if I connect also the RF cable I get the picture you can see in the video...

What can be the culprit?

Maybe this cable, that I use to connect the Commodores, is not RGB?

Many thanks,

Davide

https://www.icloud.com/photos/#0L-cypV2 ... p0TEWtjtjQ

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Chema
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Re: Oric 1 with messy video problem

Post by Chema » Sat Sep 14, 2019 11:51 am

I think the C64 outputs a composite video signal not RGB. Even the pin-out is different.

You need a cable made specifically for the Oric. And the use the RGB input.

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iss
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Re: Oric 1 with messy video problem

Post by iss » Sat Sep 14, 2019 12:14 pm

Looking in the Service Manual (page 16) there should be NO problem to use SCART input with Oric:
monitor.png
But definitely you must put some voltage (1–3 V → RGB) at SCART'S Pin 16 !
Disassemble the SCART connector and connect an external battery (or maybe 2 x 1.5 V in series) 'minus' goes to Pin 5 and 'plus' to Pin 16.
I bet it will work :)

AmintaOric
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Re: Oric 1 with messy video problem

Post by AmintaOric » Sat Sep 14, 2019 1:00 pm

Thanks to all!

So I hope that the wrong cable is the only culprit!

I've bought this one on ebay, https://www.ebay.it/itm/Oric-1-Atmos-Hi ... 2749.l2649, when it comes I'll let you know if all woks good!

Thanks!

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iss
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Re: Oric 1 with messy video problem

Post by iss » Sat Sep 14, 2019 1:02 pm

... and after you confirm that above solution works, maybe you will ask for battery-less setup ;).
Here you can find voltage-doubler+charge-pump using synchro signal.

Or you can solder DIN-5-male to DIN-5-male cable:
din-5.png
I hope this helps :)

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Re: Oric 1 with messy video problem

Post by mikeb » Sat Sep 14, 2019 6:02 pm

AmintaOric wrote:
Sat Sep 14, 2019 1:20 am
I can see it only if, together with the s-video to scart cable, I'm keeping attached also the RF cable!
Just on that point, it sounds like your lead is not connecting the ground connection through correctly, and you are "stealing" a ground connection using the RF/coax lead's shield, from Oric to the TV!

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Chema
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Re: Oric 1 with messy video problem

Post by Chema » Sat Sep 14, 2019 7:31 pm

If he is using a c64 cable, it is not compatible at all. Check:
http://www.cbmitapages.it/tecnico/C64scart.gif
Versus the Oric http://www.48katmos.freeuk.com/ports.htm

And not only that, but the expected video signal is composite, not RGB. He could be feeding the blue channel as the composite video and the SYNC as GND...

Strange he even got a picture.

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