Hacking Dreamcast video and sound

[Stormdemon]

Hello! Any Dreamcast user out there with experience building cabinets with a Dreamcast insde? I hope you can help me with this:

First doubt:
I have a Dreamcast and I plug it to my SCART TV with a RGB cable. I'm going to hack this cable in order to drive the sound to a pair of amplified PC speakers. Is it enough to cut and wire left input sound and right input sound to the speakers or do I need any ground too? I'll have the DC connected to the TV for video and to the speakers for sound.

Second doubt:
I've noticed some games output 15khz non-interlace picture as you can see real scanlines . For instance, SF3 double impact or Last Blade 2. Others, most of them, output interlace picture (eg SF3 thrird strike). My question is: what modification do I need to make to the RGB cable in order to obtain non-interlace picture in all games? I've been reading DC2JAMMA and I don't have clear if I need that circuit or not? It says it may be needed for some arcade monitors and not for others, but what about SCART TVs?

[SirPoonga]

There is some info on hacking the dreamcast on this site.  Not sure if there is the info you are looking for.  It mostly is about hacking a vga box.

[Stormdemon]

I'd rather hack a RBG cable than the VGA box because not all games run in the VGABOX.

[CanStick]

Hi there...I can answer your first doubt for you....yes, you will need a ground.  Take the ground from the cable and split it to go with both audio channels to the speakers.

Sorry I can't help you with your second doubt though....

Terry.

[Frostillicus]

I'd rather hack a RBG cable than the VGA box because not all games run in the VGABOX.

I've found that if you connect the vga box about 10 seconds after you power on the DC all my my non-vga box games will run.

[Minwah]

Hi there...I can answer your first doubt for you....yes, you will need a ground.  Take the ground from the cable and split it to go with both audio channels to the speakers.

Sorry I can't help you with your second doubt though....

Terry.

Correct, but also remember that audio to a Scart plug is not amplified - so it will be crap (or not work at all) if you wire directly to speakers.  You'll need an amp between DC and speakers.

Second Doubt:

I think the circuit described at DC2Jamma is simply for obtaining the correct video sync from the Scart lead for an arcade monitor.  Since you are using a Scart TV you do not need to do this - it already has the correct composite sync.

AFAIK you are stuck with whichever mode the DC outputs - I could be wrong tho...

I personally have never seen any reason to alter the Scart output of the DC - it looks great!

[CanStick]

Hi there...I can answer your first doubt for you....yes, you will need a ground.  Take the ground from the cable and split it to go with both audio channels to the speakers.

Sorry I can't help you with your second doubt though....

Terry.

Correct, but also remember that audio to a Scart plug is not amplified - so it will be crap (or not work at all) if you wire directly to speakers.  You'll need an amp between DC and speakers.

I don't know anything about SCART, but in the first post, he said he was going to connect it to amplified speakers...  

If he wasn't, then yes, for sure some kind of amp would be needed...

[Generic Eric]

Check this place out.  Very informative site.

[Minwah]

I don't know anything about SCART, but in the first post, he said he was going to connect it to amplified speakers...  

If he wasn't, then yes, for sure some kind of amp would be needed...

My mistake, sorry I must've misread  , no amp will be needed then.