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Amiga1992 25 October 2013 16:39

I have a question. Th CX encoder chip in the Amiga 600 and 1200 has luma and chroma outputs. Can I just use those to make an s-video output? I saw people mounting svideo kits to this encoder chip but I quite don't understand why.

Jope 25 October 2013 16:52

Quote:

Originally Posted by Akira (Post 918482)
I have a question. Th CX encoder chip in the Amiga 600 and 1200 has luma and chroma outputs. Can I just use those to make an s-video output? I saw people mounting svideo kits to this encoder chip but I quite don't understand why.

It needs a few external components to get the S-Video out into the proper format, so that's why the kits exist.

Solo761 25 October 2013 21:52

Quote:

Originally Posted by kipper2k (Post 918470)
I get them from Digikey all the time, they have PAl and NTSC capable frequencies.

http://www.digikey.ca/product-search...2333?k=crystal

Thanks, I haven't thought of them, I looked on rsdelivers site as I ordered from them before :).

*edit*

Now I remember why I never ordered anything from them, they estimate shipping for 10 SMD crystals to Croatia $120 :crazy

Loedown 26 October 2013 06:45

Quote:

Originally Posted by Solo761 (Post 918553)
Thanks, I haven't thought of them, I looked on rsdelivers site as I ordered from them before :).

*edit*

Now I remember why I never ordered anything from them, they estimate shipping for 10 SMD crystals to Croatia $120 :crazy

Sometimes it's the shipping that kills the deal, I have looked at Digikey here several times in Australia but their postage is a killer, Farnell, WES, RS and Rockby are my main suppliers, sometimes a better deal including postage than from the part's originators plus their postage.

Hewitson 26 October 2013 15:56

Quote:

Originally Posted by Akira (Post 918482)
I have a question. Th CX encoder chip in the Amiga 600 and 1200 has luma and chroma outputs. Can I just use those to make an s-video output?

This is what I do on the Megadrive. The luma output does need to be amplified with a transistor or op-amp and then run through a filter to remove noise.

Unfortunately I can't give a more detailed response than that as I don't have a schematic handy.

Amiga1992 26 October 2013 16:44

Quote:

Originally Posted by Hewitson (Post 918676)
This is what I do on the Megadrive. The luma output does need to be amplified with a transistor or op-amp and then run through a filter to remove noise.

Unfortunately I can't give a more detailed response than that as I don't have a schematic handy.

Does the MD have the same encoder chip?

Jope 26 October 2013 19:58

Quote:

Originally Posted by Akira (Post 918691)
Does the MD have the same encoder chip?

IIRC it does.

Here's the circuit you need to make, it's basically the same as in the CD32 schematics.
http://www.amigazone.fi/saku/41/osas.../liitannat.gif

Solo761 26 October 2013 23:04

Quote:

Originally Posted by Loedown (Post 918617)
Sometimes it's the shipping that kills the deal, I have looked at Digikey here several times in Australia but their postage is a killer, Farnell, WES, RS and Rockby are my main suppliers, sometimes a better deal including postage than from the part's originators plus their postage.

Thanks, I'll check with some of the other companies you mentioned. Already checked Farnell and so far it's the cheapest, "only" $20 for shipping :D.

Amiga1992 27 October 2013 00:30

Quote:

Originally Posted by Jope (Post 918714)
IIRC it does.

Here's the circuit you need to make, it's basically the same as in the CD32 schematics.
http://www.amigazone.fi/saku/41/osas.../liitannat.gif

Seems like it's the same on MD model 1 only. MD model 2 has a pin compatible but inferior quality Samsung encoder.

Here is a different circuit though, can anybody tell what the difference is and which one might be better?:

http://retrotimegames.com/wpimages/wpe07eb93a_05_06.jpg

It has a transistor on the Y line.

Jope 27 October 2013 16:10

Now would be the time to dig out the datasheets for the chips. Perhaps the CXA1145P is subtly different to the CXA1145M?

Anyway, Commodore got it to work in the CD32 with a cap + resistor on each line, so I guess it's close enough. :-)

Sandro 27 October 2013 16:19

Quote:

Originally Posted by Akira (Post 918784)
Seems like it's the same on MD model 1 only. MD model 2 has a pin compatible but inferior quality Samsung encoder.

Here is a different circuit though, can anybody tell what the difference is and which one might be better?:

http://retrotimegames.com/wpimages/wpe07eb93a_05_06.jpg

It has a transistor on the Y line.

that genesis circuit is not official is a hack invented by this guy

http://www.jamma-nation-x.com/jammax/genesismods.html

basic difference is it uses a npn transistor to amplify luma

which one might be better? try them both and see yourself the results, they are easy to build

also there is another circuit for svideo http://aminet.net/docs/hard/S-Video_A1200.lzh
but this one is much more complicated

leon22 11 September 2017 19:23

Hi!

I know this is rather an old thread but maybe anyone can help me:

is the schematic from narmi (downloadable from his site: http://www3.telus.net/narmi/AmigaVideo.zip) functional with PAL or which product do you suggest for a PAL Amiga 500?!

Thank you very much!


greets leon22


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