Laseractive Component Video

[Segasonicfan]

I was stumbling around looking for datasheets of Laseractive chips and I found this one.  It looks to be the main encoder circuit for the Game Pack(s) and since it outputs R-Y, B-Y, and Y all it should take is a couple opamps to covert it to a full Pr Pb Y Signal.  Anyone have the knowhow to do this?  There's a component->RGB schem that marks the YUV to PrPbY conversion point, maybe I can try that.  

-Segasonicfan

[Guest]

Will somebody help me out on this?

[Lawrence]

Your last post indicated you were going to go ahead and try it ("Maybe I can try that.")  It's possible we were all waiting for your success story.

I was looking at the LA service manual just now.  The RGB board seems like it would have readily available component-type signals, but I don't know if they're usable, nor do I really care (Component sucks), otherwise I'd be all over this mod.

Let us know how your efforts go.

[Guest]

Lawrence, any chance you could send me that service manual?  That would be EXTREMELY helpful to me

I tried directly connecting the YUV signals and that definitely didn't work (on my TV).  However, when I directly connect them to the PSOne LCD I get a pretty decent image.  That's connecting to the LCDs RGB inputs though.

Also, have you tried wiring the RGB lines to an RGB screen yet?  I think I'll go ahead and try that soon and rip the sync using an LM1881.  While RGB is the best Component better suits me b/c that's what my TV takes.  Not to mention if I get it working I can easily convert to RGB...

-Segasonicfan

[Segasonicfan]

EDIT:  I meant a COPY of the service manual, not the real thing obviously  Just a scan of the video info would be amazingly helpful to me and much appreciated

-Segasonicfan

[Lawrence]

Sorry, it's over a hundred pages, many of them fold-out schematics.  I'll not be spending an afternoon copying this anytime soon.  =(

[Segasonicfan]

What if I paid you something for it?  I only need the Component video info.... :/

-Segasonicfan

[Lawrence]

There's nothing to know.  RGB comes from the game pack and goes directly to the ROHM encoder.  You've got the encoder datasheet, what else do you need?

[EC]

Any update on this one?

Playing LaserActive in composite is really horrid.

[ido8bit]

Just a thought here (I don't have a aLaseractive, so I can't look into this), but wouldn't taking the RGB output from the game pack loose the LD video from LD games.  I'm assuming the point where the RGB signal enters the encoder is before it is overlaid on the LD video.  As LD video is in composite from the LD disc itself I doubt it exists in RGB in the machine.

I could be wrong of course.  Posting the datasheet for the encoder could shed more light on this.

 

[EC]

Yes, I was thinking that as well but to at least have a 100% working S-video mod would be wonderful.

[Segasonicfan]

Yeah, I'll have to work on this more later.  I stopped working on this last year since I fried one of my Laseractives :/  I think now I'm competent enough to avoid such things

-Segasonicfan

[ido8bit]

Yes, I was thinking that as well but to at least have a 100% working S-video mod would be wonderful.

An S-video mod would probably have the same problem as an RGB mod with LD games.  As the video on an LD is recorded as composite there is no way to get native S-video (or RGB, or component) from an LD source.  

On Laserdisc players that have an S-video output this is provided by a composite to S-video decoder in the player.  This will only provide a better picture than the composite output when the decoder in the player is better than the decoder in the TV it is connected to.  The same applies to a few rare LD players with RGB outputs.  

Perhaps an external video decoder/processor would be a better option to improve Laseractive video as you wouldn't need to risk frying a rare console and the decoder/processor could be used with other devices.  
 

[GZeus]

Things get complicated, but I'd recommend getting the RGB from the video game section, then take the composite from the LD side, run them out seperately, and then do the needed processing/mixing.
 

[blackevilweredragon]

Yes, I was thinking that as well but to at least have a 100% working S-video mod would be wonderful.

An S-video mod would probably have the same problem as an RGB mod with LD games.  As the video on an LD is recorded as composite there is no way to get native S-video (or RGB, or component) from an LD source.  

On Laserdisc players that have an S-video output this is provided by a composite to S-video decoder in the player.  This will only provide a better picture than the composite output when the decoder in the player is better than the decoder in the TV it is connected to.  The same applies to a few rare LD players with RGB outputs.  

Perhaps an external video decoder/processor would be a better option to improve Laseractive video as you wouldn't need to risk frying a rare console and the decoder/processor could be used with other devices.

Not only that, but isn't LaserDisc video Analog, and not even Digital?  (Where the audio IS digital)

[Lawrence]

Laserdiscs have both analogue and digitial audio tracks.  Earlier discs had only analogue.

An RGB mod for playing cart and CD games on the LA should be easy.  LD games is, as mentioned,a  completely different problem.

[GZeus]

Laserdiscs have both analogue and digitial audio tracks.  Earlier discs had only analogue.

An RGB mod for playing cart and CD games on the LA should be easy.  LD games is, as mentioned,a  completely different problem.

Well, there's no digital audio on the LA discs, as that's all data, so the music is analog.

[Segasonicfan]

I did try pulling the RGB signals back when this thread was first created.  If memory serves the image was too dark and needs some amping.  I have too many projects in the works now but when I have time this will definitely be on my workbench.

-Segasonicfan

[Segasonicfan]

It's not much of an update but here's a pic of the RGB + Sync lines in the Laseractive.  I won't be able to work on this for a while but I'm pretty sure they need to be amped.  The signals are correct according to both the video encoder they go to and the printing on the PCB:



-Segasonicfan