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Author Topic: Converting TV signal from Amiga to HDMI?  (Read 38902 times)

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Offline AmmoJammo

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Re: Converting TV signal from Amiga to HDMI?
« Reply #14 from previous page: February 13, 2015, 11:19:04 PM »
Quote from: jdryyz;783907
Just out of curiosity, I connected my second SCART to Component box (same seller sent me a replacement) and it did not display the same level of green, so more evidence that the box is the source.

Also, it would appear that the "green" cable is not actually the source of the green in the component signal:

http://en.wikipedia.org/wiki/YPbPr

So getting back to this clever idea you had to try this in the first place, does this conclude that this is a sync problem with what is coming out of the box? Does this help you in your quest to make your own mods?

As far as I'm aware, the sync on the rgb port of the amiga should be the same as the sync on the monochrome output...

I'm wondering if your scart cable is actually wrong, as I believe they both should simply be composite sync...

Oh yeah, its not green, that's why I keep putting "green" in quotes ;)

But it does effect the amount of green from memory... :P
 

Offline AmmoJammo

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Re: Converting TV signal from Amiga to HDMI?
« Reply #15 on: February 14, 2015, 11:29:53 AM »
I've been trying this with a Sega Megadrive/Genesis... and I'm confused....

This tv won't take the composite signal, from the megadrive, on the "green" component input, and it doesn't work with the scart to component adapter...

But... it will take a composite signal from another source, and display a black and white image, so it doesn't seem to be a bi/tri level sync issue at all?
 

Offline AmmoJammo

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Re: Converting TV signal from Amiga to HDMI?
« Reply #16 on: February 14, 2015, 12:03:27 PM »
Megadrive update (for my own reference) it won't display the composite signal on the "green" component input at all...

it will display the "green" output from the scart to component adapter when fed into the composite input, in black and white, but it constantly drops sync....

BRB, getting my master system!

Master system does as I would expect... anything fed into the component "green" says "not support"
Anything fed into the composite input displays an image (black and white for the "green" from the component output from the scart to component adapter)
« Last Edit: February 14, 2015, 12:16:49 PM by AmmoJammo »
 

Offline AmmoJammo

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Re: Converting TV signal from Amiga to HDMI?
« Reply #17 on: February 14, 2015, 09:35:31 PM »
Where did your current cable come from? How is it wired?
 

Offline AmmoJammo

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Re: Converting TV signal from Amiga to HDMI?
« Reply #18 on: February 15, 2015, 08:40:55 AM »
I'm beginning to think that these issues actually have nothing to do with bi/tri level sync, but are rather the Amiga/Segas 15khz refresh rate rearing its ugly head again....

This TV has no issue with the scart to component adapter when connected to the RGB output of a Nintendo Gamecube....

It makes me wonder if the monochrome output of the Amiga 500 is actually 31Khz... or at least higher than 15khz...

I was reading that apparently it was intended for word processing on a monochrome screen, and apparently had less flicker in interlaced mode than the RGB output of the Amiga.....

Its all starting to make sense now isn't it?
 

Offline AmmoJammo

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Re: Converting TV signal from Amiga to HDMI?
« Reply #19 on: February 15, 2015, 09:08:04 AM »
I have a Dell 2405fpw that I figured would fail with the scart to component adapter... but it doesn't...

Although there's some jitter, it displays both the Megadrive and Master Systems fine, so I assume will also display the Amiga...

It reports the signal as being 240p or 288p depending if its 60Hz or 50Hz...
 

Offline AmmoJammo

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Re: Converting TV signal from Amiga to HDMI?
« Reply #20 on: February 15, 2015, 10:51:14 AM »
Sony TV reports the sega as 480i...

The tv's I've had issues with are Kogan, and they seem to be horrible... they don't even display composite properly...
 

Offline AmmoJammo

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Re: Converting TV signal from Amiga to HDMI?
« Reply #21 on: February 17, 2015, 09:13:34 AM »
Both the Megadrive and Master system are outputting 15.6Khz horizontal, 49.7Hz vertical sync...

The plug in Tetris game, that will sync when connected to the "green" component outputs 15.6Khz, and 50Hz....

So, that answered nothing at all!

I'm about to test the Amiga 500's monochrome output, but have a feeling its going to be the same 15.6Khz and answer nothing!

Edit: Amiga 500, 15.6Khz/49.9Hz...
« Last Edit: February 17, 2015, 09:15:42 AM by AmmoJammo »
 

Offline AmmoJammo

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Re: Converting TV signal from Amiga to HDMI?
« Reply #22 on: February 21, 2015, 02:50:33 AM »
Today I made a discovery...

This time a Super Nintendo!

The internet told me I needed to connect each of the R,G,B lines to ground, through 75 ohm resistors, but I decided to leave them out, and see what would happen...

TV reports "Not Supported" and this was a TV that had worked with everything before... (Amiga, MegaDrive, Master System, N64, Gamecube)

Stick the resistors in, works fine! SO I'm thinking the issue with the Kogan TV isn't a sync issue at all....