LaserActive RGB Mod

[SuperDeadite]

Was an easy mod, and works great.  Signals must be amped though
This only works for games fully generated by the PACs.
If you play an LD game, you will see the sprites in RGB, but no LD Video will be shown.
You can also feed the RGB into a 32X, so yes 32X will work with an LA by doing this.





Composite:


RGB:

[BlueBMW]

Awesome!  Glad to see that it worked!  I didn't have an amp handy to test it fully.  Unamped it was visible from a sega pac but dim.  From an nec pac it wasn't strong enough to work right.  So yes it must be amped.

[PunkCryborg]

bravo guys! makes me want one even more....

[kattare]

Nice work with the mod!

I've looked at doing this mod on my Laseractive, but had read elsewhere (and now you've confirmed it) that the LD games don't work through it.  Kinda makes it a moot point doesn't it?  Why keep around a massive Laseractive other than to play the LD games?  ;-)  I keep hoping someone will find a way to snag RGB out of the laserdisc side of the unit and recombine it.

[BlueBMW]

It might be possible to extract the LD video data, separate it back into rgb and then combine them again for rgb out.  From what I understand however, LD video is natively composite so you wouldn't gain anything from having RGB on the LD video.  The only benefit would be that you'd have rgb on the pac graphics overlay.

[SuperDeadite]

Well, it takes up less space then having a MD/MCD and PCE-DUO sitting next to each other. 
The LD games are composite native (live all LD videos), so it's impossible to get RGB without
using some kind of video processor, but it wouldn't look any better then the composite would.

[SignOfZeta]

Yeah, you'd need some extraordinarily high end shit to get a mixed RGB signal, the sort of broadcast-grade thing that costs $10,000 and isn't even being made anymore.

I can see getting a superior s-video from it though with a lot of work. I think the two sides mux their video after a Y/C separation but the chip they used only outputs composite. I suppose that could be improved upon.

[thesteve]

seperating the comp back to RGB and mixing it is simple.
you just need a color decoder chip from an old tv to seperate the colors.
6 resistors to mix it.
an rgb amp to output it and your done.

[kattare]

Well, it takes up less space then having a MD/MCD and PCE-DUO sitting next to each other. 
The LD games are composite native (live all LD videos), so it's impossible to get RGB without
using some kind of video processor, but it wouldn't look any better then the composite would.

That's true.  I hadn't thought of the sega side of things.

seperating the comp back to RGB and mixing it is simple.
you just need a color decoder chip from an old tv to seperate the colors.
6 resistors to mix it.
an rgb amp to output it and your done.

What kind of signal degredation would you see on the LD side of things with the color decoder?  Sounds like it might be a pretty nice mod to do. 

Looks like (if you can find a place to buy it) something like the Motorola TDA3330P would do the trick. PDF: http://www.eetindia.co.in/ARTICLES/2000DEC/2000DEC05_AMD_AN2.PDF?SOURCES=DOWNLOAD

This is pretty tempting: http://www.converters.tv/products/ntsc_to_rgb/43.html  Seems to have lots of easy to access adjustments and would save a lot of build time.

[SignOfZeta]

seperating the comp back to RGB and mixing it is simple.
you just need a color decoder chip from an old tv to seperate the colors.
6 resistors to mix it.
an rgb amp to output it and your done.

Yeah but...what's that going to actually look like?

[thesteve]

the signal degradation of the LD (comp) output should be the same as any television using comp input.
the RGB overlay from the pac should be without degradation

[SignOfZeta]

the signal degradation of the LD (comp) output should be the same as any television using comp

Yeah, that's what I'm getting at. This varies a lot from TV to TV.

[thesteve]

so it depends on how well the vid decoder is tuned.
most of the later sets are great at it.
anything with a picture tube uses the required circuit.

[SignOfZeta]

Yes, but this circuit is effectively being used whenever you plug a stock LA into any TV. For that sort of work to be any kind of upgrade you need something well above average.

[thesteve]

not true
the pac supplied grafx will be superior with the mod and the LD supplied backgrounds are of lower quality as recorded.
so you wont be improving on the quality of the LD playback, only the game supplied portion.

[SignOfZeta]

I'd be surprised if the LD side didn't take a significant hit if premium chips weren't used.

[SuperDeadite]

DAMN DAMN DAMN DAMN

Ok so did more testing, RGB LA + MD PAC = 100% working.
But, sadly, with a PCE PAC, the mod fucks up the Sync on Composite video.
Meaning with a PCE PAC, composite output no longer works.
So PCE games look great in RGB, but it's impossible to play PCE-LD games
with this mod as is.  I removed the mod completely, and composite video worked fine
again.  So I can't have this mod and play Vajra 2 on the same unit.

From the searching I've done, it seems the N64 has this same issue, post RGB modded and
the composite is broken.  I'm wondering if a switch to turn the mod on and off would fix this,
any ideas?

[BlueBMW]

Are you tapping the composite sync from the PAC connection lines, or are you getting it from the final composite out?  My converter wants the full composite video input so I just tapped from the composite out connection directly and it seemed to work fine.  Worst case we just have to implement a switch that opens the circuit when one wants to use regular composite out instead of RGB.

[SuperDeadite]

I took it from the RGBB pcb like in the photos and runs through the amp as well.  In RGB mode, the PCE games are fine.  But the normal composite video out won't sync (LD games and videos won't sync with pce pac).  Guess I could try tapping from the RCA plug instead I suppose.  Weird as hell that with the MD PAC, everything works perfectly, problem is only with the PCE PAC..

[BlueBMW]

I took it from the RGBB pcb like in the photos and runs through the amp as well.  In RGB mode, the PCE games are fine.  But the normal composite video out won't sync (LD games and videos won't sync with pce pac).  Guess I could try tapping from the RCA plug instead I suppose.  Weird as hell that with the MD PAC, everything works perfectly, problem is only with the PCE PAC..

Only thing I can think of is a signal strength issue, since we're stealing some of the signal for the RGB out and maybe whats left on the line isn't strong enough for the rest of the system to use.  As I found, the sega PAC rgb signal was strong enough to be visible without an amp, but the PCE one was too weak.  So from that I can surmise that the PCE pacs dont put out as strong of a signal period.

[thesteve]

just means you need to add the RGB amp  so the LD player uses the amped sig too

[schweaty]

sorry to resurrect an old thread, but has there been any progress on RGB modding a Laseractive?

is there a definitive guide somewhere with schematics on how to do this?

i've been looking in this forum and the web for hours, but i havent seen anything really definitive on how to go about doing this.  my first technical question is, what is being tapped for the RGB signal?  the PAC or womewhere on the Laseractive board?  if its the PAC, is there a way to do this while preserving the ability to swap between PACs?  will thesteve / turbokon's component board work?

[BlueBMW]

When I've done the RGB mod on one I did it on the back panel.  You can tap the RGB signals on one of the boards that attaches to the rear panel.  You wont have to modify PACs at all.  They natively send RGB to the laseractive where it gets encoded into composite.  I think the points might even be labeled on the board.

http://www.cyberroach.com/new_laseractive_pics/misc/clda100_repair/page059.gif
http://www.cyberroach.com/new_laseractive_pics/misc/clda100_repair/page060.gif

[schweaty]

BB,

Thanks for the awesome response.  I see exactly where to pull RGB, G, and 5V.  I see a number of places to pull composite sync.  My question is, where do you typically pull C Sync from?   My second question is, have you used turbokon's component board on this?  if so, is there anything else i should know?  obviously, i would like to component video mod it if i can

-dan

[PunkCryborg]

I did my LA, it was incredibly easy to do since it's all labelled so well. I don't have a NEC pac to test that on though. I just used one of Broken's amps and installed a panel mount DIN 8 on the back. It looks amazing. I think sega stuff looks better in RGB on my LA than on my model 1 genesis

[BlueBMW]

I have not tried the component board on it yet.  I think I just pulled composite straight from the composite jack on the same panel.  Seems like that usually works for most things.

Once the system itself is modded then all your pacs will run work with it.  What wont work is Laseractive games themselves.  The LD video is combined with encoded composite video from the PACs and then fed out from there.  We would have to figure out how to decode the LD video (luma + chroma) into RGB and then combine that with the PAC RGB in order for LA games to be in RGB.  As it is if you play an LA game with your RGB youll just see the PAC overlay graphics and none of the LD video.