Emulating Pioneer LaserActive (Mega-LD) games

MNc99 · Post by **MNc99** » Thu May 24, 2012 2:23 am

Misty wrote:
MNc99 wrote:
BlueBMW wrote:EDIT:

Did some looking over the schematic.... looks like we might want to look at the LD video inputs at the BA7230LS chip on the RGBB board. That chip looks to be the final encoder that combines the LD video with the RGB overlay from the PAC.

Schematic: http://www.cyberroach.com/new_laseracti ... age059.gif

Datasheet for the BA7230LS: http://pdf1.alldatasheet.com/datasheet- ... 230LS.html
Just reposting this in case it's of any help to anyone.

By the way, Nemesis, did you ever find out if the other games besides Space Berserker have 'fuck' in the code? That'd be hilarious to see.
Also relevant:

http://www.gamesx.com/misctech/laseractive.htm
http://www.gamesx.com/misctech/laseractivergb.htm

Instructions on adding s-video and RGB output by tapping the video before it gets combined with the PACs or builtin display.

Nice find!

LocalH · Post by **LocalH** » Thu May 24, 2012 6:29 am

RGB won't really help in terms of video capture, since the disc stores composite video and the only relatively cheap RGB capture card I know of is the SweetSpot (link currently down, unfortunately), but with the RGB mod essentially just decoding the composite signal, best to just capture the composite signal yourself. S-Video might help or might not, depending on whether the unit has a comb filter. If not, you want to use the standard composite output and use either the capture card's comb filter or a software version if the card doesn't have a good one. Of course, with Nemesis talking about not using a cheap capture card, I'll wager that the software comb filter won't be needed.

LAPProject · Post by **LAPProject** » Thu May 24, 2012 6:41 am

While I do have access to a high-quality capture card, I don't have a non-LA LD player, so I'm afraid I'll be out of luck for this one. Regardless, let me know if I can help.

Pyramid Patrol
3D Museum (a little rot, negligible)
Rocket Coaster
Hyperion (a little rot, negligible)

LocalH · Post by **LocalH** » Thu May 24, 2012 7:03 am

Depending on the content that the rot obscures, it may be possible to manually repair it (or, if it slightly differs each time it's played, it'd be worth taking multiple captures of affected segments until the rot averages out).

LAPProject · Post by **LAPProject** » Thu May 24, 2012 7:30 am

LocalH wrote:Depending on the content that the rot obscures, it may be possible to manually repair it (or, if it slightly differs each time it's played, it'd be worth taking multiple captures of affected segments until the rot averages out).

Most of it's just scratch distortion, I believe. It's for a split second. The only disc with actual rot is 3D Museum (that's likely because it's double-sided).

Nemesis · Post by **Nemesis** » Thu May 24, 2012 10:23 am

We should be able to eliminate any errors due to scratches or laser rot easily enough by ripping video from another disk and comparing differences. I'd like to try and rip as many disks as possible from each person who's willing to donate, even if we've already ripped some of them before, because we can't rule out the possibility of alternate versions of these games. It seems unlikely these games had large enough production runs for there to be different revisions of the games, but you never know. At the very least, it'll help with cleaning up the video.

Misty · Post by **Misty** » Thu May 24, 2012 12:42 pm

LocalH wrote:RGB won't really help in terms of video capture, since the disc stores composite video and the only relatively cheap RGB capture card I know of is the SweetSpot (link currently down, unfortunately), but with the RGB mod essentially just decoding the composite signal, best to just capture the composite signal yourself. S-Video might help or might not, depending on whether the unit has a comb filter. If not, you want to use the standard composite output and use either the capture card's comb filter or a software version if the card doesn't have a good one. Of course, with Nemesis talking about not using a cheap capture card, I'll wager that the software comb filter won't be needed.

If this were a normal LD player you'd be right, but like I mentioned, the problem is that the LA passes the composite signal from the disc through a fairly torturous composite -> separate -> merge with PAC or overlay -> convert back to composite process. The GameSX article claims that the s-video mod actually does produce better signal since it grabs the video earlier in the chain before it's had some unnecessary extra processing.

LocalH · Post by **LocalH** » Thu May 24, 2012 3:53 pm

Misty wrote:If this were a normal LD player you'd be right, but like I mentioned, the problem is that the LA passes the composite signal from the disc through a fairly torturous composite -> separate -> merge with PAC or overlay -> convert back to composite process. The GameSX article claims that the s-video mod actually does produce better signal since it grabs the video earlier in the chain before it's had some unnecessary extra processing.

In that case, it may be worth investigating and trying to locate a point before the composite signal is separated to pull it from. It all depends on the quality of the end result, as most capture devices won't apply a comb filter to S-Video input, so if there's not a comb filter already in the LA circuitry, then I would recommend this. If there is a comb filter (which there very well may be), then it may not even matter whether you tap separated Y/C or composite from before the processing chain.

MNc99 · Post by **MNc99** » Thu May 24, 2012 11:33 pm

Nemesis, did you have a name picked for your emulator? This project should have a title.

Misty · Post by **Misty** » Thu May 24, 2012 11:36 pm

LocalH wrote:In that case, it may be worth investigating and trying to locate a point before the composite signal is separated to pull it from. It all depends on the quality of the end result, as most capture devices won't apply a comb filter to S-Video input, so if there's not a comb filter already in the LA circuitry, then I would recommend this. If there is a comb filter (which there very well may be), then it may not even matter whether you tap separated Y/C or composite from before the processing chain.

I would say it's improbable there's a comb filter. Comb filters were still considered a pretty high-end feature for consumer gear at the time. The LA is specced like one of Pioneer's lower-end players of the time, aside from the expensive game features; they reserved any comb filter at all for higher-end players.

LAPProject · Post by **LAPProject** » Fri May 25, 2012 1:56 am

MNc99 wrote:Nemesis, did you have a name picked for your emulator? This project should have a title.

I like RadioActive myself. Just a thought.

MNc99 · Post by **MNc99** » Fri May 25, 2012 11:17 pm

What do you guys think of LaseRedux?

ICEknight · Post by **ICEknight** » Sat May 26, 2012 3:20 am

Mega-LSD. =P

Flygon · Post by **Flygon** » Sat May 26, 2012 2:45 pm

Composite Active.

Misty · Post by **Misty** » Sat May 26, 2012 3:23 pm

Semi-offtopic, but you guys might be interested: Manhattan Requiem got an iOS port not long ago and is on sale for 99 cents right now. It doesn't have voice acting, but the text translation is 100% identical to the Laseractive version, which was the only way to play the game in English until now. It's one of the very few LA gems.