Composite AV output planned!

Discuss the CreatiVision hardware: models, revisions, fixing, hacking and modding.
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MADrigal
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Composite AV output planned!

Post by MADrigal » Wed Jun 25, 2008 8:58 pm

Giovanni and I planned to try to obtain a "AV Composite output" signal from the creatiVision.

We'll hopefully attempt at such modding next weekend, stay tuned! ;)
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carlsson
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Re: Composite AV output planned!

Post by carlsson » Thu Jun 26, 2008 12:33 pm

Nice. Does the creatiVision have the same kind of built-in RF modulator as found in e.g. ZX Spectrum, BBC Micro, Commodore 64 and dozens of others? If so, I think I know how this composite video hack will happen. The RF modulator already takes a composite signal as its input, so it is a matter of routing the signal past the RF. I have modded my ZX Spectrum in this way, so the RF output now outputs composite video (same connector, the RF modulator was bypassed).

If the RF signal is generated in other ways directly on the motherboard, it may a more challenging task but good luck!
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Re: Composite AV output planned!

Post by carlsson » Thu Aug 14, 2008 11:35 am

How did it go, are you getting cv (composite video) on your cV (creatiVision) now? :-D

I've read some systems may have a rather weak composite signal going into the RF modulator, so you have to amplify it in some way to use it directly. Of course you need to route the audio out to its own connector as well. Just the other minute I came across a step-by-step guide how to get composite video out of the Intellivision, which included some daughter board but I think it only consisted of the RCA jacks, no other electronics?
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Re: Composite AV output planned!

Post by MADrigal » Thu Aug 14, 2008 12:04 pm

Unfortunately Giovanni and I really had no time to attempt with the mod yet. :oops:
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mr_bogus
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Re: Composite AV output planned!

Post by mr_bogus » Sat Oct 10, 2009 1:35 pm

Did you ever get to try this? I have brought my CV back to UK from South Africa, but the RF signal in UK has a slightly different frequency to the rest of Europe! So i battle to get colour picture, and the sound is a mess :(
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Re: Composite AV output planned!

Post by MADrigal » Sat Oct 10, 2009 4:03 pm

Hi Paul,
no, I had no chance to actually test the composite mod. But I'm almost sure of what the solution is. Let's meet on MSN next week, and I'll explain you how-to :)

Luca
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Re: Composite AV output planned!

Post by carlsson » Mon Apr 30, 2012 10:13 am

Now as scouter3d mentioned the replacement VDP with VGA output, perhaps someone should have another look at possible component or composite output from the Creativision as it stands? I suppose previous experiences from Colecovision, TI-99/4A etc can be harvested if required.
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Re: Composite AV output planned!

Post by MADrigal » Mon Apr 30, 2012 10:26 am

even though my technician-friend swears that the composite output mod he did on my Rameses works... i still haven't put my hands back on my Rameses to test how it actually works. :-(

i also would love to see what Scouter3D could to to add the VGA or composite output to the Creativision.
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Re: Composite AV output planned!

Post by carlsson » Mon Apr 30, 2012 12:53 pm

As far as I know, the 9929 (PAL) outputs R-Y, B-Y, Y. I used to think it is similar but not identical to modern component video YPbPr, but perhaps those actually are the same type of signals? The 9918A (NTSC) instead has composite output, but it would only be useful for the Japanese consoles, as I understand Creativision/Wizzard never was released in an NTSC version for the US market?

So the composite mod Giovanni did must've been a circuit to combine the three components, possibly with some buffering or amplifying to get proper signal strength.

Another idea is to use a standalone RGB/component (YUV) to VGA adapter. Those can be ordered from China (eBay) for less than $40 including shipping. I bought one last year, but as it didn't match my application, I just sold it to my friend. However it seems for YPbPr signals it is specified 480p, 576p, 720p, 1080p that I'm uncertain if the 9929 would be able to match either of. (No, I'm not stupid - I just don't understand this)
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Re: Composite AV output planned!

Post by MADrigal » Mon Apr 30, 2012 12:59 pm

my friend's name is gavino, it's not giovanni (the one of the creativemu team) :-)

as far as i know, he took the composite signal from the console (vdp RY-BY-Y -> some IC on the pcb -> composite -> rf modulator) right before the RF modulator, amplified it a bit and connected to a tv-connector.

no more infos at this moment, i still have to put my hands on the console, test it and watch what he's doing.

your thoughts about the NTSC 9918 and PAL 9929 are correct. making a composite output from a 9918 is extremely simple, might require some IC for the 9929, but as far as I Know, that IC is on the PAL creativision pcb already.
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