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Laseractive RGB+32X...DONE

Started by Segasonicfan, June 08, 2007, 08:09:15 pm

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Segasonicfan

Hey folks,
 I FINALLY got around to installing RGB and LD S-video on my Laseractive unit.  Aside from RGB just naturally kicking ass it makes the 32X add-on possible (since the 32X takes the RGB lines from the Genny for conversion).  Well I finally got it all working:

http://i18.photobucket.com/albums/b134/Seg...active32x-1.jpg
http://i18.photobucket.com/albums/b134/Seg...eractive32x.jpg
http://i18.photobucket.com/albums/b134/Seg...laseracrive.jpg

Sorry about the poor pics, it was hard to get both the system and the LCD picture.  The RGB lines of the Laseractive are on the RGB assembly board that Lawrence posted about so long ago.  However, they are very weak RGB signals and are further weakened by being fed through resistors.  So pulling them from the jumpers is actually not the best place.  The best way is to pull them from the ribbon cable pins.  The pinout is as follows:

1- B
2- GND
3- G
4- GND
5- R
6- GND
7- IR
8- SEL IR

C Sync is pulled from the circled pin on the chroma encoder and comes from pin 15 of the first Ribbon cable connector (there's even a jumper labeled C Sync on the top of the PCB so you can't miss it).

Sine the RGB lines were still too weak before the resistors I used a THS7314 3-channel video amp.  You have to put AC coupling caps on the input though.

To get the 32X system to connect it is also necessary to drill away the plastic ledge along the bottom.  You can also just use a pass through cart.  I liked just drilling the ledge to get a nice snug fit but I will need to wire new outputs for the controller ports since it covers those up.  Drill RGB in and out jacks on the 32X and voila, Laseractive 32x :)  Best of all, the 32X still uses the Genny for all audio processing so you can even use the digital optical output!

I am also installing a dual bios soon for multi CD and cartridge region support.  I have also installed the AC3 audio upgrade for 5.1 surround sound with LD's :)  Found the info for it here: http://www.laserdiscarchive.co.uk/laserdis...ac3_upgrade.htm

Here's a pic of the circuit I built: http://i18.photobucket.com/albums/b134/Seg...ctiveAC3mod.jpg


I also took some nice pics of the Sega pack insides since there aren't any online and I was blown away by the quality.  I think it is quite possibly the finest quality Genesis system in existence:

http://i18.photobucket.com/albums/b134/Seg...ve/100_1250.jpg
http://i18.photobucket.com/albums/b134/Seg...ve/100_1249.jpg
http://i18.photobucket.com/albums/b134/Seg...ve/100_1248.jpg
http://i18.photobucket.com/albums/b134/Seg...ve/100_1253.jpg
http://i18.photobucket.com/albums/b134/Seg...ve/100_1254.jpg
http://i18.photobucket.com/albums/b134/Seg...ve/100_1255.jpg
http://i18.photobucket.com/albums/b134/Seg...ve/100_1252.jpg

Sega used only the most absurdly expensive parts.  Most of this wasn't even necessary, lol.  The crystals are all in pricey metal surface mount casings, so are the electrolytic caps (not cheap in 1993).  The 68ks and every other circuit in there is surface mount as well except for a couple opamps.  The connector to the sub board is even top notch quality- these kind of high density connectors were never used in consoles of that era, not even the CDX.  Add in interference protection for even the friggin controller lines and you just have the most ridiculous Genesis around.


I am also probably going to overclock the Genesis 68k CPU along with a 50hz video switch....but does anyone think this could harm the system?  I am pretty sure there were no Laseractives ever designed for PAL so it definitely won't support the video option.  Just something to stop the lockout on PAL MD games.  There isn't even a jumper for the setting though, I will have to actually lift up and solder to the Sega CPU pin :/

Anyway this thread probably won't serve much purpose to people but at least it shows Lawrence that his Laseractive info finally went to good use :)

-Segasonicfan


NFG

QuoteAnyway this thread probably won't serve much purpose to people but at least it shows Lawrence that his Laseractive info finally went to good use

Woot!!  Good to hear.  =D

Richter X

June 10, 2007, 12:44:46 pm #2 Last Edit: June 10, 2007, 12:45:00 pm by Richter X
I have a question, how does it sound? All the Segas I've been using lately look and sound like crap, though I've never gotten my hands on a CDX or anything that rare.

Segasonicfan

The Laseractive is renowned for having the best audio of any Sega system.  Gen 1 and Gen 2 systems have pitiful sound quality because most of them use POS opamps.  The Gen3 fixed that and so did the CDX so they sound very nice.  The Laseractive is in a league of its own though.

-Segasonicfan

Richter X

In that case, could someone get some recordings from it? I wanna hear this! ^_^

Segasonicfan

hard to do with digital optical output...not even sure how to do that really unless there is some sort of PCI card that has an input for it.  Definitely doesn't look like something I can provide :/

RobIvy64

June 18, 2007, 06:00:21 am #6 Last Edit: June 18, 2007, 06:01:13 am by RobIvy64
Building a small audio filter for you Genesis sounds better than any Genesis 3, LA or CDX:

Sonic and Knuckles audio through a filter





Mod courtesy of Tiido and Underground Console Mods
B)
"Console Mods" lurker

Richter X

June 18, 2007, 12:00:55 pm #7 Last Edit: June 18, 2007, 12:10:16 pm by Richter X
Sounds nice. Got any more details to the mod?

EDIT: Found the mod. Could someone put it on THIS site as well?

RobIvy64

QuoteSounds nice. Got any more details to the mod?

EDIT: Found the mod. Could someone put it on THIS site as well?

The schematics are on there if you want to build the PCB.

(Thats my forum BTW) :)

Tiido, the guy who came up with that mod, is a Genesis modding master.
"Console Mods" lurker

Richter X

It sounds pretty awesome. No distortion at all! I could use this on both of my Segas to fix the audio on 'em (has late model 1 and a model 2).

Also, I heard the Wondermega/X'Eye enhances the audio of the SegaCD. Is there a way to replicate this on other systems?

Segasonicfan

Ah, nice to see the mod finally available.  It sounds nice (esp the water level) but the Laseractive will still give you better audio.  It doesn't use the Yamaha chip for sound processing.  You don't get any of that background noise on the Laseractive and thed. distortion problems are fixed.

-Segasonicfan

RobIvy64

June 18, 2007, 09:09:25 pm #11 Last Edit: June 18, 2007, 09:12:10 pm by RobIvy64
The LA doesn't have filtered audio quality and does have the Yamaha YM2612 FM synth. On the LA i've played, you still get the background noise and the PCM distortion is still there (which will always be there simply because the audio hardware does not support PCM very well). The games are programmed to produce sound using that specific hardware, so the YM2612 is needed.

The Yamaha chip may not be physically located on the LA's PCB as a seperate chip, but that doesn't mean it isn't integrated within another large IC.
"Console Mods" lurker

Segasonicfan

well I took pics of the entire inside of the Sega pack and I don't see the Yamaha chip.  The pics are in the first post of this thread FYI.

I somehow doubt Pioneer would incorporate the Yamaha chip into the CLD-A100 unit.  I could check the service manual right now but I'm pretty damn sure it's not in the unit plus I'm just too lazy.

Did you listen to the Laseractive using digital optical audio output?  When did you play one?

Not putting down your friends mod, I find it very impressive and will incorporate into my own systems later.

-Segasonicfan

RobIvy64

The 315-xxx chip used in the LA Genesis module is the same part used in the Genesis model 2, which has the Yamaha FM synth incorporated in it. Just because you don't see it doesn't mean it's not there. It is a necessary part.

"Console Mods" lurker

Segasonicfan

actually, you have no idea how that chip works unless you have official documentation on it.  A lot of the Genny 2's poor audio quality can be accounted for by the opamps used among other things.  I'm sure the circuit incorporates its own audio circuity but you have no clue what that might be.  It could very well be of higher quality.

I see you didn't answer my questions on the Laseractive :/

-Segasonicfan

RobIvy64

Removing the Yamaha YM2612 would cause the audio to stop functioning, or better yet, the Genesis won't even boot. I may knot know exactly what's in there, but I wouldn't bet the farm that the 2612 circuitry is not there. The FM channels aren't being emulated :P.

You can't change the core design of a console once people start making games for it. I suppose you think the Genesis 3 lacks a 68000, Z80, RAM, and YM2612?

I played a LA on October 13, 2005 at 12:16:53 PM.
"Console Mods" lurker

blackevilweredragon

the same exact 315 chip?  does that mean we could get digital audio out of the genesis 2 then?

RobIvy64

Quotethe same exact 315 chip?  does that mean we could get digital audio out of the genesis 2 then?

Eh, i'm sure you could if you built the right circuitry for it. The LA module has a few extra Pioneer-labelled chips that I don't know what they do exactly. Probably some sort of interface controller, but it could be for the digital audio.
"Console Mods" lurker

Segasonicfan

QuoteYou can't change the core design of a console once people start making games for it. I suppose you think the Genesis 3 lacks a 68000, Z80, RAM, and YM2612?


They are integrated so once again, you don't know the exact quality and functionality.  The Genesis 3 actually doesn't have a full Z80 integrated, which is why it can't play Sega CD and 32X games  ;)

QuoteI played a LA on October 13, 2005 at 12:16:53 PM.


More or your usual unnecessary rudeness.  :rolleyes:

-Segasonicfan

RobIvy64

June 19, 2007, 07:57:40 am #19 Last Edit: June 19, 2007, 07:59:06 am by RobIvy64
Quote
QuoteYou can't change the core design of a console once people start making games for it. I suppose you think the Genesis 3 lacks a 68000, Z80, RAM, and YM2612?


They are integrated so once again, you don't know the exact quality and functionality.  The Genesis 3 actually doesn't have a full Z80 integrated, which is why it can't play Sega CD and 32X games  ;)

QuoteI played a LA on October 13, 2005 at 12:16:53 PM.


More or your usual unnecessary rudeness.  :rolleyes:

-Segasonicfan

The Z80 is also a necessary component. The 32X doesn't work because the 7.6 MHz and 13.18 MHz clock lines are missing from the cart slot. Patching those clock lines will cause the 32x to boot on a Genesis 3, but to a yellowish screen (working on that BTW).

Go ahead and try for yourself :).

No rudeness, just facts. You can't delete necessary components from a console or you loose compatibility. I may not have the datasheets for those ICs, but I can guarantee that Sega did not remove the circuitry for components needed to play the games.

Take a Genesis and disable the Z80 and/or YM2612 and see what happens. It will be a funky adventure for you!
"Console Mods" lurker

Segasonicfan

QuoteNo rudeness, just facts.


The rudeness was your remark about the exact time you tested the Laseractive.  That isn't at all a fact, you used the exact hour and minute there just to be a jerk.


QuoteTake a Genesis and disable the Z80 and/or YM2612 and see what happens. It will be a funky adventure for you!


Lol, Sega uses pseudo z80 and 68k components within the later 315 chips.  It's not like they yanked it entirely not to mention the 2 have entirely different CPUs.  Don't be ridiculous.

Now please get over yourself I'm tired of arguing with you on these forums.  It's a nice mod but I think the Laseractive sounds better.

-Segasonicfan

RobIvy64

June 19, 2007, 10:36:40 am #21 Last Edit: June 19, 2007, 10:37:35 am by RobIvy64
Pseudo CPU? lol! Best thing i've heard all day!

The idea of a manufacturer combining cores into one ASIC to cut costs blows your mind.

The LA and Genesis have "completely different" CPUs? Tell me more!

Heh, it's pointless trying to teach you anything, believe what you will. I...

Nevermind :).
"Console Mods" lurker

blackevilweredragon

Rob, my idea about the 32X and the clock lines worked?  (based from your VR hack)

Wow, and I don't even have a Genesis 3!  :P

RobIvy64

June 19, 2007, 10:43:01 am #23 Last Edit: June 19, 2007, 10:44:39 am by RobIvy64
QuoteRob, my idea about the 32X and the clock lines worked?  (based from your VR hack)

Wow, and I don't even have a Genesis 3!  :P

Yep, it boots but the picture is all yellowish :(.

VR works of course, since both the 32X and VR cart pull a clock signal from the Genesis' cart slot.

Since it's a multi-layer PCB, it has been a trick sourcing the other missing address lines.
"Console Mods" lurker

Epicenter

June 20, 2007, 04:06:36 am #24 Last Edit: June 20, 2007, 04:13:57 am by Epicenter
Um. Segasonicfan-- it's quite obvious the ASICs used in the MegaDrive Model 2 and LaserActive systems incorporate an accurate clone of the YM2612, Z80, and in some cases, 68000 ICs. If they did not, the same software would not function on them, as these three processors all have very specific instruction sets and will not operate with the same object code with even small changes. This is the reason 68010 and later-revision 68000 processors cause numerous poorly-coded MD/Genesis games to crash-- they have small "security fixes" and other changes to the design that are incompatible with old binaries.

In the YM2612's case, the chip is digital; the only difference made in its implementation will be how the output is handled to create the final analog audio stream. I imagine, though, a digital audio implementation on the MD would likely make the audio sound "too perfect" and lose much of the charm of the original analog output. Much like an emulator or RGB video.

To answer your question about overclocking the 68k or switching it to 50Hz being harmful-- neither should do any sort of damage. These are both documented functions on the 68K and big fat Sega ASICs, respectively, and if the feature is unsupported, then nothing should happen at all.
- Epicenter
Epic Gaming Admin

RobIvy64

QuoteTake a Genesis and disable the Z80 and/or YM2612 and see what happens. It will be a funky adventure for you!


Bump.
"Console Mods" lurker

Segasonicfan

June 20, 2007, 07:33:27 am #26 Last Edit: June 20, 2007, 07:33:54 am by Segasonicfan
Epicenter, thanks for the input.  I actually already listed pin 46 on the processor and tied it to ground...and it worked!  Now the system can play PAL lockout MD games :)

I've also installed a dual region bios but I ordered another one that will hold all regions within the chip.  So when I'm done this will be a 100% universal import friendly Laseractive!

BTW, I also found out what the AC3 thing was...apparently it was the pre-DTS original 5.1 surround sound encoding.  The Laseractive supports AC3 output with a small mod (which I did) but you need to buy a couple old (and still expensive) decoders to use it.

-Segasonicfan

RobIvy64

Quoteit's quite obvious the ASICs used in the MegaDrive Model 2 and LaserActive systems incorporate an accurate clone of the YM2612, Z80, and in some cases, 68000 ICs. If they did not, the same software would not function on them, as these three processors all have very specific instruction sets and will not operate with the same object code with even small changes.


Precisely :)  
"Console Mods" lurker

strider77

seeing this has futher fueled my desire to mod my laser disc player for RGB. it must be possible. does anyone have any suggestiongs as to locating the RGB and sync lines inside the player?

Midori

August 27, 2007, 07:52:29 am #29 Last Edit: August 27, 2007, 07:52:46 am by Midori
You can't mod a Laserdisc player for RGB since they don't output RGB. They only output composite video natively. If you want RGB you'll have to convert the composite signal to RGB.

strider77

all right...   i had seen european ld players with scart sockets so i thought it might be a possibility.

ニユ-マン

August 28, 2007, 06:17:25 am #31 Last Edit: August 28, 2007, 06:18:28 am by ニユ-マ
All the Euro LD players have scart sockets, a few of the older models (from Sony and Philips) do output RGB and  a German firm used to sell an RGB output kit for the later Pioneers, but...
QuoteThey only output composite video natively


Precisely, there's no point since LD are composite.

pro7

great thing  B) .  the problem... all pictures are dead link  :blink: . can you reupload them somewhere?

ac3 too is cool...  as it has a digital output it can even play Dts laserdiscs.

but too bad that the LA had very poor quality tray and other inside plastic parts.  many are broken from long trips :( .   i searched info but none who had a broken laseractive had repaired them.   i did it myself for two units with much patience and replaced some with aluminium/metal.   but still had on the 2nd unit with a psu which blown up  (expensive and non common to other ld players from pioneer )

Richter X

Crap, now all the images are gone. Can someone please put the Sega Genesis 2 sound filter mod on the GameSX wiki or something? Maybe some more audio samples too? ^.^<3

Joe Redifer

The OGG audio demo of the filtered Genesis sound was very interesting, but it sounds as if some hooligan came in to my room and cranked up the bass controls on my receiver almost all the way while I wasn't looking.  The Genesis already has plenty of bass as it is.  Other than the "way too much bass", it sounds good.  What Genesis model did you add the filter too?

Richter X

It was a Model 2 I believe, but couldn't it also work on a Late Model 1 Genesis?

Segasonicfan

ill have to reup the pics when i get some free time.  I have a spare broken Laserdisc with perfect disc trays and all that.  i think they were great quality btw, ive had 3 of them survive horrible shipping from across the country. 

stt1

I found this very helpful. Just added RGB-amp -board to LA and almost ready for testing it  :)

Segasonicfan

I'm glad this info is helping someone.  I recently took a ton of pictures and uploaded a bunch of info on repairing Laseractives over on my website:

https://segasonicfan.wixsite.com/retro/repair-logs