CD with ESR

[xtc-king]

hello every1, have a little question, is it possible to burn an UDF CD and not a DVD.
an UDF CD to play in ESR ? ?

when you have option to chose to make a cd into UDF CD, and then its possible to patch in ESR, will it work in ESR ? i have tryed to burn a psx1 game in esr, it didnt.

[JNABK]

No, ESR doesnt support CD backups at all.

[TnA]

No, ESR doesnt support CD backups at all.

True + PS1-Games do not work at all with ESR (or another released PS2-App as of yet), but the "why" is an entirely different case.

[WiiPower]

ESR patching patches the disc to video dvd, because if it's just a DVD-R the drive itself refuses to read the disc, right?

It's probably asked 100 times already, but wouldn't be the 1st try to get CDs to work, by patching them to data-audio hybrid discs?

Also the loading of ps1 games changed on V9(?) ps2, so it doesn't do a 2nd check if it's really a ps1 game in the drive. (which is why the ps1 swap trick works)

I have no idea how the game loading on a ps2 works, but i'm thinking about this:
Insert a ps1 game, dump the memory/state of the ps2 to usb storage. Then insert a patched ps1 game disc that is also an audio disc, load the memory/state from usb and then do whatever ulaunchelf does to boot ps1 games on the swap trick. Of course it would only work on V9+ ps2s.

[Berion]

Disc veryfication is not the only one problem. Theoretically it's possible to launch PS2 game from UMCDR/CDX but no one write loader for it yet - and probably this will be never changed (we really need it? many games is easy to move on DVD media, other have easy to find lba tables).

[dlanor]

ESR patching patches the disc to video dvd, because if it's just a DVD-R the drive itself refuses to read the disc, right?

It's probably asked 100 times already, but wouldn't be the 1st try to get CDs to work, by patching them to data-audio hybrid discs?

That has already been done on various occasions, most recently (I think) by EEUG (the author of SMS) for his media player, which does support a hybrid format called "CDDAFS" == "CDDA File System". He also developed a PC application for making such discs, intended to allow playback of movies from burned CDs using an unmodded console, which works fine.

But it would be inappropriate to use the same methods to make a generic device driver patch, like that of ESR, to allow booting of normal games from such hybrid discs. And that is because the CDDA format has NO built-in error correction check fields, which is crucial for safe use of executable programs from either CD or DVD media. There will ALWAYS be some bit errors, and the ECC fields of real CD-ROM and DVD-ROM formats are essential to correct those errors, as needed for reliable use of executables.

It would in theory be possible to implement ECC in software, for use with hybrid CDDA discs, using parts of each CDDA track for ECC fields, but the resulting access speed would probably be so slow as to make practical launching and normal use of the games impossible.

This problem does not exist for the ESR/DVD-Video format, since it does have ECC fields. Standard DVD-Video playback requires reliable ECC too, and this is normally sufficient for executable programs as well.

Also the loading of ps1 games changed on V9(?) ps2, so it doesn't do a 2nd check if it's really a ps1 game in the drive. (which is why the ps1 swap trick works)

I have no idea how the game loading on a ps2 works, but i'm thinking about this:
Insert a ps1 game, dump the memory/state of the ps2 to usb storage. Then insert a patched ps1 game disc that is also an audio disc, load the memory/state from usb and then do whatever ulaunchelf does to boot ps1 games on the swap trick. Of course it would only work on V9+ ps2s.

That method would never work reliably even on a v9 console, and no serious developer will waste his time by investing it in a project that works only on a single console model. So this will never happen...

Finally, with the new 'Open PS2 Loader' project coming along so nicely, there is no reason to look desperately for ways of running games off a physical CD. It is far more convenient to use virtual discs installed on a PC or on a USB drive instead.

Best regards: dlanor

[WiiPower]

But Open PS2 Loader won't play ps1 games. Hmm, doesn't the swap trick also work on the slims?

Anyways, i had the idea, because Castlevania Symphony of the Night is already a disc with audio track. One of my ps2s is able to read that CD-R and play the audio track, and it doesn't do a check for the media once the ps1 game booting process is started. After reading your info i think, it may have some special file system, so if a game was patched for it, the reading commands would need to be patched.(=much more work that i thought)

Also, i think i remember that ps1 games are written as mode2 to discs, which would mean, it's next to the audio disc format already. Hmm, "[...]and the PlayStation uses a mixed-mode format with most data in Mode 2/Form 1 and streaming audio/video data in Mode 2/Form 2[...]"(http://en.wikipedia.org/wiki/PlayStation). What's Mode 2/Form 1|2?

[dlanor]

But Open PS2 Loader won't play ps1 games.

Of course not, and neither can any other PS2 application or device driver (except for the PS2PSXe emulator of ffgriever, which is still unreleased).

Developing a PS2 device driver to allow normal booting of PS1 games is not possible, since all PS2 device drivers are killed by the switch to PS1 mode, as used for the normal PS2 method of running PS1 games.

In PS1 compatibility mode the IOP RAM space and IOP CPU normally used for PS2 device drivers are instead used as main RAM and main CPU of a PS1. So these two usages are in total opposition and can never coexist at the same time.

Hmm, doesn't the swap trick also work on the slims?

Some disc swapping methods do work, but probably NOT the one you were thinking of, for PS1 discs.

----- re: your additional ideas about CD formats and their use for PS1 games
All of those ideas are made impossible to use as you wanted by the facts stated above.

Regardless of what PS2 device drivers we create, and what hybrid disc formats these may implement, none of them can be used when the console switches to PS1 mode.

Best regards: dlanor