"Let's make GD ROM emulation happen" Facebook group.

Yeah the support isn't complete. But he has very low room to code it, so it's understandable.

Is multisession in mode1 even legal?

 

Here are the two UGC firmware I have.

USB-GDRom Controller Firmwares

 

It works if you want the first session to be a data dummy track to make a disc that's technically data/data instead of audio/data (using DUMMY.BIN instead of AUDIO.RAW), but you can't put game data there. You can try to create a data/data disc with a merged session 1 ISO, but the game won't be able to access the files in the first session if you burn it in Mode 1. You can only make valid data/data discs with game content in session 1 if you burn both sessions as Mode 2 XA Form 1, and GDEMU does support such discs. It just won't let you use a Mode 1 dummy as the first session, even though the DC will boot such a disc. I guess it's probably the most obscure format, but the DC does boot it as a MIL-CD, even if audio/data is the more common method of creating an "empty" first session (or as close to empty as you can get).

 

Eventhough mode1 works, I think mode2 form1 is the "canonical" way to make multisession data discs. Anyways it shouldn't be harder to insert than a mode1 session... My selfboot pack (fixed to 45000LBA) uses mode2 form1 tracks all the time.

 

As far as the Dreamcast is concerned, that's correct, but I don't think it's the case for CDs in general. The Orange Book standard introduced the concept of sessions, but AFAIK you're allowed to use both Mode 1 and Mode 2 tracks in each session as you please, mainly because Orange Book predates the introduction of XA mode by a year or so. The Blue Book standard (for Enhanced CD) requires the second session to have a Mode 2 XA Form 1 track, but it's proprietary, as is Sega's MIL-CD (which is essentially the same thing, except instead of putting generic PC data into the second session to complement the music, they wanted to put a Dreamcast program, instead).

I think the gist is that if you want to use only data, Mode 1 is fine, but if you want to mix audio and data, you're expected to use Mode 2 XA Form 1 for PC files and Form 2 for video (since it has no ECC and thus provides greater capacity for user data). Both Mode 1 and Mode 2 XA Form 1 support merging multisession ISOs together, AFAIK, since a CD-ROM drive will only read the TOC of the final session on a disc (thus causing files from previous sessions to become inaccessible if you don't merge their TOCs into the TOC of your new session).

 

Love reading all this technical jargon, but haven't a clue what it means lol

 

Did you attach the resistor to bring the voltage down to 12v? I did this and have had no heat issues.

 

I wonder who you got it from when sending euro in PayPal. He has no paypal. The resistor helps if your not using a vga box.

My next order has been delayed due to no communication since 4/7. Mnemo was to give update on the 18th but no replys.

 

Oh I did not know that. So that means it's not doing a thing for me then. I should probably run my other dreamcast with a cd inside and see if the temperature stays the same. If the one with the USB GDROM is much hotter then I should either add a fan or just change the psu to one that'll run cooler.

 

Here's a good link to learn about CD without being too much engineer-oriented.

http://www.soundonsound.com/sos/jan98/articles/cdformats.htm

 

It can cause issues with vga output

 

Interesting to know!

I have been using a HANZO VGA adapter with my USB-GDROM and felt like my temperatures were just fine.

I guess that explains it.

Are you saying that if you use an added-on resistor AND a VGA box, that you will have issues, crans? What sort of issues? VGA not working or dim or something?

 

I guess some vga boxes use the 12V, thus fixing the floating 12V issue. If there's already a resistor, maybe the vgabox wouldn't get enough power. It's be interesting to test a DC with the 12V removed with a vgabox just to see.

 

I just got my hanzo today to replace my crappy retrobit box. Maybe I should try removing the resistor and see what happens.

 

Hey, I actually ordered from Crans and let him know the issues I had with my Dreamcast setup. So if you have any questions you can feel free to ask me.

My setup was a VA0 Dreamcast -> Hanzo -> Kenzei -> SCART -> XRGB Mini. When I first hooked everything up with the included resistor I got only audio and no picture. Thinking this was odd, I removed my complex A/V setup in exchange for normal composite cables. At this point I realized that I was getting an image, but that it was bouncing...It wouldn't hold steady, something similar to a vertical collapse on a monitor.

Seeing that the USB GDRom board was working, I figured I'd try removing the resistor and hooking it up to composite cables again. At this point I didn't notice any more of the visual stabilization issues. Went to hook it back up to the original setup I had before and now everything worked. I haven't done long term tests on how hot the system is getting, so YMMV. I will likely try to hook some sort of additional cooling set up into the system just to be safe. Not sure its something to do with my Dreamcast, revision of Hanzo, or any other combination of possibilities....

 

how many Ohm is the resistor?

 

300 Ohms

 

if gdrom draws 200mA at 12V line then

R=V/I => R=12/0.2=60 Ohm
(correct me if i am wrong)

can you try a smaller resistor 60 Ohm

 

I haven't had issues with VGA using the resistor but maybe there's something I'm not really noticing. Instead of opening up this dreamcast, think I'll plug the VGA box to the other dreamcast and look at the display. The hanzo box sure is better than what I was using. Even the sound is so much cleaner and crisp.

 

It be great if you could tell us what those issues would be my friend. Just to be informed