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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Chain on November 30, 2006, 07:30:19 AM

Title: A520 s-video hack :)
Post by: Chain on November 30, 2006, 07:30:19 AM
Ive tried it yesterday, its really noticeable improvements! 8-)
There are also 3 pictures (composite, svideo, rgb) for comparison:

http://chain.3dgrafika.cz/temp/A520hack/
Title: Re: A520 s-video hack :)
Post by: derringer3 on November 30, 2006, 08:07:39 AM
Good job!
However I never hacked my a520, because I get a rgb-scart cable, to connect my amy to a TFT.
Title: Re: A520 s-video hack :)
Post by: nadoom on November 30, 2006, 09:55:18 AM
Hey there thats pretty cool stuff u did there, do you think you could provide some instructions to people such as my self who has a reasonable level of knowledge?


Cheers

Nadoom
Title: Re: A520 s-video hack :)
Post by: Chain on November 30, 2006, 10:48:04 AM
well described here, step by step:

http://members.iinet.net.au/~davem2/overclock/a520.html
Title: Re: A520 s-video hack :)
Post by: pVC on November 30, 2006, 12:38:56 PM
It's pretty easy to make s-video mod for at least a1200..  maybe it works on other amigas too. You just need two capacitors and two resistors. I've lost the page on my bookmarks, but have to dig.. the mod was meant for other console/computer, but works also on amiga..
Title: Re: A520 s-video hack :)
Post by: nadoom on November 30, 2006, 12:50:24 PM
danke!
Title: Re: A520 s-video hack :)
Post by: Chain on November 30, 2006, 01:18:24 PM
Quote

pVC wrote:
It's pretty easy to make s-video mod for at least a1200..


i know, but A520hack is more flexible, i can use it with other miggys
Title: Re: A520 s-video hack :)
Post by: neuroflip on November 30, 2006, 01:46:26 PM
Fantastic!!! i always want somthing like that... to improve my video signal quality using a common tvbox (throught svideo!)

thx... probably this weekend i'll try someting!!!
Title: Re: A520 s-video hack :)
Post by: pedro7 on November 30, 2006, 02:02:22 PM
There's an s-video hack for the a1200 on aminet, apparently copied from the circuit in the cd32.

I couldn't find the a520 hack on aminet though. Can anyone upload things like this to aminet or is only the author allowed? I'm wondering as the site with the hack on hasn't been updated in a couple of years and if it goes down the hack and all the other amiga info on there will be lost  :-(
Title: Re: A520 s-video hack :)
Post by: Tomas on November 30, 2006, 04:33:11 PM
Too bad i suck at electronics stuff...
I wish someone could produce and sell something like that for a reasonable price.
I dont even know where to find a rgb2scart cable.
Title: Re: A520 s-video hack :)
Post by: adolescent on November 30, 2006, 06:02:57 PM
They're out there.  I have a box and have seen others (Prevue, etc.).  I got mine on eBay for ~$30.  I think the main problem is new RGB encoder chips aren't that cheap.  I've heard you can scavenge them out of old Megadrive/Genesis and PS1 consoles though.
Title: Re: A520 s-video hack :)
Post by: hardlink on November 30, 2006, 06:35:57 PM
Quote

adolescent wrote:
They're out there.  I have a box and have seen others (Prevue, etc.).  I got mine on eBay for ~$30.  I think the main problem is new RGB encoder chips aren't that cheap.  I've heard you can scavenge them out of old Megadrive/Genesis and PS1 consoles though.


Or you can get a good quality genlock. A GVP G-Lock just sold on Ebay for US$5, and it has a beautiful S-video output, much better than a hacked A520.
Title: Re: A520 s-video hack :)
Post by: bobamu on November 30, 2006, 06:51:26 PM
eek, those poor innocent genesis's, genesises, er.. genesi ?  :-o er, megadrives  :lol:

(sorry, drank too much coke)

A quick look on google brings up a few interesting things for converting rgb to video, it also brings up a few things that make me think the guys are some kind of con artists

this looks interesting tho http://www.jrok.com/hardware/RGB.html
the guy wants to be emailed for the price tho, so it could still be horrific

if there's a desparate need for some kind of converter unit maybe someone could knock a few together, are the chips to do the function really that nasty expensive?
Title: Re: A520 s-video hack :)
Post by: adolescent on November 30, 2006, 07:10:58 PM
Quote

hardlink wrote:

Or you can get a good quality genlock. A GVP G-Lock just sold on Ebay for US$5, and it has a beautiful S-video output, much better than a hacked A520.


But, doesn't the G-Lock require software to do the switching/fading?  (ie. it won't work for non system compliant applications)
Title: Re: A520 s-video hack :)
Post by: adolescent on November 30, 2006, 07:21:29 PM
@bobamu

IIRC, the JROK is $85.  I think it (or maybe it was the Neobitz converter) uses the Analog Devices AD724JR RGB encoder   ~15 for the chip.

BTW, the Neobitz is a neat piece with a cheap DIY option.  (And Jeff Kurtz is a nice guy...)
Title: Re: A520 s-video hack :)
Post by: hardlink on November 30, 2006, 08:46:20 PM
Quote

adolescent wrote:
But, doesn't the G-Lock require software to do the switching/fading?  (ie. it won't work for non system compliant applications)


Yes, software is required for switching/fading, and a cable to the joustick port!, but from what I remember when you power it up, even without the joy cable or software, it defaults to converting the Amiga RGB to video. I don't remember if S-video is on by default.
Title: Re: A520 s-video hack :)
Post by: Dr_Righteous on November 30, 2006, 11:07:35 PM
I use a Supergen SX (got it DIRT CHEAP on ebay) for SVideo, input it into my Pinnacle capture board, and use AMCap to display it. Coupled with a KVM switch to my Voodoo Banshee card on a Mediator, it works great!
Title: Re: A520 s-video hack :)
Post by: Chain on November 30, 2006, 11:33:43 PM
PAL genlocks with Y/C out are rare(=read - expensive) here as hell. A520 costs me only 5 quids.

composite on 1084S
(http://chain.3dgrafika.cz/temp/A520hack/composite.jpg)
 
A520 S-video on 1084S
(http://chain.3dgrafika.cz/temp/A520hack/svideo.jpg)

RGB cable on 1084S
(http://chain.3dgrafika.cz/temp/A520hack/rgb.jpg)
Title: Re: A520 s-video hack :)
Post by: Dr_Righteous on December 01, 2006, 12:37:36 AM
The question is, has anyone ever tried using the JROK or Neobitz on an Amiga?

[edit]
If indeed the Neobitz does work, it wouldn't be difficult to design a video slot board based on those components to fit in A2/3/4K video slots. IIRC, Analog signals exist on the video bus. Onboard SVideo!
[/edit]
Title: Re: A520 s-video hack :)
Post by: melange on December 02, 2006, 03:16:20 AM
Awesome, glad to see you tried it and it worked.  I have done the hack and mine almost worked but didn't produce quite the correct output.  I think I got a resister value wrong somewhere now, and I will go back and check it to see if I can get it to work now that I know someone else has followed the instructions and made it go. :-)

I have built the A1200 S-video Mod into My A1200 and one of in my A600, and about to do it again for another A1200.  It works really nicely and I can actually use Workbench and see it all clearly on my 69cm Flat screen TV.  I am considering buying some flat screen TV's to use instead of 1084S's because the result is comparable, and I get a really HUGE Amiga screen.
I mounted the SVHS socket under the PCMCIA port on the A600, and just in front of the floppy drive on the opposite side on the A1200.  Sockets fit well and both machines output very nicely :-))

The same hack cannot be performed inside the A500, it dosen't have the RGB convertor chip inside it.  But as pointed out above, you can hack the chip out of other older hardware and I looked around and found other off the shelf chips that performed the same function.
Title: Re: A520 s-video hack :)
Post by: K7HTH on December 02, 2006, 04:42:07 AM
Not a bad option is one cannot secure a SD/FF.
Title: Re: A520 s-video hack :)
Post by: clockmstr on December 02, 2006, 06:19:31 AM
I added VGA out to an A520.

Works pretty well, if I get around to it I'll post it here.
Quote

Chain wrote:
Ive tried it yesterday, its really noticeable improvements! 8-)
There are also 3 pictures (composite, svideo, rgb) for comparison:

http://chain.3dgrafika.cz/temp/A520hack/
Title: Re: A520 s-video hack :)
Post by: Chain on December 02, 2006, 10:16:43 AM
Quote

melange wrote:
Awesome, glad to see you tried it and it worked.  I have done the hack and mine almost worked but didn't produce quite the correct output.  I think I got a resister value wrong somewhere now, and I will go back and check it to see if I can get it to work now that I know someone else has followed the instructions and made it go. :-)


 :-D  I just want to try it if its works at first. also ive measured every resistor before soldering it.
That mod has slso one big advantage - you can reverse it back to TV-mod if you need.