Sanyo can create 1.4 GB CD-Rs

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Sanyo can create 1.4 GB CD-Rs

Post by q_006 » Sun Jan 14, 2007 2:32 pm

Well I figure that since everyone is trying to make Dreamcast games that this will be helpful to anyone. http://www.afterdawn.com/news/archive/3379.cfm
I do have a question though. I remember some people saying that when you finally burn your game you have to burn it so the data is toward the outer ends of the disc and not toward the middle. 1, if that's true, then why? 2, how would one go about doing that?
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Post by az_bont » Sun Jan 14, 2007 3:04 pm

When people talk of pushing data to the outer bounds of the disc, they are talking about the process of dummying. This is where you place a large dummy file at the start of the disc, so that all of a game's data is nearest the edge.

If you look at a CD-R, you will see that most of a disc's area (and therefore available space for burning data) is contained towards the outer edge of the disc. By pushing the data to this portion, you can improve loading times for three reasons:

1. The laser head has to move less physical distance
2. The laser can read a great deal more data per spin of the disc
3. The laser head does not have to move as far to access different data files

The reduced laser head movement also helps to improve its lifetime, as it suffers from less wear and tear.

It was once very common for people to dummy their homebrew and emulator discs, but I believe it is now commonly thought that it would not make any real difference in the vast majority of cases, as emulators and homebrew usually load all the data they need once, into the RAM.

I believe that the various proprietary methods for extending the capacity of a CD-R have already been tested to be incompatible with the Dreamcast, as they pack the data too dense for a normal CD-ROM drive to read (whereas most normal CD-ROM drives can read data from the GD-ROM portions of a Dreamcast's disc, with a little encouragement).
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Post by q_006 » Sun Jan 14, 2007 5:31 pm

As far as "dummying" goes, what kind of file do you put? Any file (ex: word doc, notepad, powerpoint, avi file)?

Also does the DC read the 800MB and the 870MB (99 minutes) discs? If yes, then the HD-Burn on those would still be readable since it has more space than a normal CD-R (650MB). Right?
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Post by az_bont » Sun Jan 14, 2007 5:41 pm

q_006 wrote:As far as "dummying" goes, what kind of file do you put? Any file (ex: word doc, notepad, powerpoint, avi file)?
You can use anything, as the Dreamcast won't even read it. There are plenty of tools out there that will quickly create files consisting of all zeroes, which compress (with ZIP etc.) to practically 0kb.
q_006 wrote:Also does the DC read the 800MB and the 870MB (99 minutes) discs? If yes, then the HD-Burn on those would still be readable since it has more space than a normal CD-R (650MB). Right?
The technology behind 99 minute CD-Rs isn't the same as HD-Burn. The Dreamcast will read the discs, however. About a year ago, somebody released a warezed version of the previosuly-unreleased "D2", which required 99 minute CD-Rs.
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Post by Christuserloeser » Sun Jan 14, 2007 10:15 pm

BootDreams automatically dummies your homebrew images ;)
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Post by Ex-Cyber » Mon Jan 15, 2007 1:48 am

Plextor did something similar but less aggressive several years ago with their "GigaRec" firmware feature.
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Post by Skynet » Mon Jan 15, 2007 3:52 am

The technology behind 99 minute CD-Rs isn't the same as HD-Burn. The Dreamcast will read the discs, however. About a year ago, somebody released a warezed version of the previosuly-unreleased "D2", which required 99 minute CD-Rs.
I hate to say this but there was a game that I warezed before I was able to buy it (yes I did buy it :P) and I had it on a 99minute CD-R. It ran fine, as fine as a warezed game can run. I'm not warez bragging or anything here, don't get me wrong. As I stated I did infact buy the game probably 6 months later, even less IIRC. But 99minute discs do work fine.
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Post by firewire1394 » Mon Jan 15, 2007 7:18 am

Skynet wrote:I hate to say this but there was a game that I warezed.
SHAME, SHAME, SHAME :x whats worse, you offered me a copy :guffaw:
it was shenmue 2 yeah? :|

this is gonna get locked now :lol:
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Post by Christuserloeser » Mon Jan 15, 2007 7:22 am

Which is a shame as I think az_bont's posted some very interesting information that not many people do know about.
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Post by q_006 » Mon Jan 15, 2007 7:46 am

az_bont wrote:
q_006 wrote:Also does the DC read the 800MB and the 870MB (99 minutes) discs? If yes, then the HD-Burn on those would still be readable since it has more space than a normal CD-R (650MB). Right?
The technology behind 99 minute CD-Rs isn't the same as HD-Burn. The Dreamcast will read the discs, however. About a year ago, somebody released a warezed version of the previosuly-unreleased "D2", which required 99 minute CD-Rs.
Well I meant using the HD-Burn on a 99 minutes disc vs. using HD-Burn on a 650 MB disc. I'm assuming that since the 99 minutes disc has more space and using HD-Burn on it would result in data not being compacted as much and therefore allowing the DC to read them.

Sorry for not being clear the first time.
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