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

WOW!!! Incredible stuff

 

Has anyone else noticed this is the most viewed active topic and #2 most viewed topic in the Dreamcast section? :O

 

I'm not an engineer, no do I plan to attempt any projects, so please be easy on me as I'm coming from purely a curious point of mind. Saying thus, I have a question.


With the advent of the impending GD-ROM emulation, is it possible to finally allow DVD playback through use of IDE DVD Players if it were possible to create software/modify the firmware/bios of the Dreamcast?

Also, does the board that's being worked on deem the internal GD-ROM of the Dreamcast useless? Or perhaps even demand you to physically remove it? If so, would it be possible to allow regular CD-DVD drives to read Dreamcast games similarly as to how you can trick a PC to read Dreamcast discs?

If all were to be possible (yes, even considering the potential major hardships involved) would it also be possible to create a SUPER Dreamcast modification with the help of GD-ROM emulation that allows DVD-Playback, storing media on an IDE HDD, and Playing Dreamcast games either through HDD or CD-ROM?

Now, if this were possible, why did Sega not do it?

 

DVD playback won't happen without a hardware h.264 decoder. Too hard to add to the Dreamcast. You will be able to use most IDE devices with this board including DVD/ CD drives. No firmware or BIOS hack for the DVD playback. Needs hardware for that.

Sega didn't do it for fear of this making it easier to copy the games off and be used to distribute freely.

And yes, this board will replace the GD drive. It will sit in place of it.

That is what I've understood so far. Anyone know something different?

 

So, you can just load a GD-ROM in a CD-ROM drive instead of having to pirate?

A more general question, does GD-ROM emulation offer a "Default" rom? What I mean by that is does it offer a image that automatically starts upon powering the Dreamcast? I think it would have to, since it makes the GD-Drive obsolete, there's no way to load another OS...


For the DVD-Playback, would adding ,pre RAM help? I think I remember someone modding their DC with more RAM. Anyway, that's not really an issue as physical media is becoming more out of touch these days.

 

DVD playback needs mpeg2 not h.264. but it is still cpu intensive for dreamcast i think.

 

maybe better find out answer in reading history of creation of the Dreamcast and the Sega company at that moment.

main purpose of the gd-emu is change storage device : from exclusive "mechanical" GD-ROM to mass product "solid" & cheap SD card, "big sized" HDD, else maybe DVD-RW. also advantage is multi-game and option of easy "copy/paste" game images. something like popular the "Ever Drive", but for DreamCast.

 

i heard from SWAT - that DreamCast has quite fast cpu - so it just theoretically possible playback of DVD -video. btw if you remember, there are DviX movies for DC , and all decompression performs by main cpu: frequency of cpu ( SH4 ) -t 200mhz , and Memory is clocked at 100Mhz.
but i have no idea who wanna make such software)))

as gd-emu replaces gd-rom on hardware level, so dreamcast work with it in ordinary way, so by default it no need any new version of "boot rom", but for choosing of game images we need some file manager or menu program- like "DreamShell", it can be loaded as first or "start-up" image from gd-emu


gd-emu can have additional RAM, i plan add 4..32 mb, but it can be more... it's not the same as main memory, but can be quite fast accessed by exploit program for read and write, or acts like "frame cache" for fast loading of game images.

 

"So, you can just load a GD-ROM in a CD-ROM drive instead of having to pirate? " - i'm not sure in this option, GD-ROM is not standart disc as "cd" or "dvd", so standart cd-/dvd- drive cant accessed to GD track structure w/o any modificaton of its firmware for read original GD-ROM disc. if you remember, cd-rom or cd-player can only play cdda tracks with "warning" information)))

 

In fact some drives can read the gd-roms if you fake the toc so they're not limited by the low-density toc. The only 100% confirmed working ones are the Lite-On Ltd-165H and another one I don't remember.

Here's a tutorial I made (in french): http://dreamagain.free.fr/index.php...ft-ripper-un-gd-rom-avec-le-lecteur-de-son-pc

While a hacked firmware could potentially allow a drive to read gd-roms, no one has been sucessful at this. The yamaha cdr400 hacked firmware floating around isn't working. It's only an original gd-writer firmware that does flash a cdr400 to make it think it's a gd-writer, but it can't read or write gd-r or cd-r. Probably hardware modification would be required. This works because the gd-writers are based off cdr400 drives, so the firmware doesn't brick the drive. I tested this first hand. SImilar situation for the S303 dvd-drive firmware, although this firmware ain't a devkit gd-writer one.

FG


Off-topic cultural question: cybdyn, what does the ")))))" at the end of sentences means? I noticed that russians use that a lot and I'm curious, is it like exclamatin mark (!) ?

 

")))" it's short from " " smiles, or good reaction


"(((" - sadness, or bad reaction

 

This is what I meant. I wasn't talking about replacing the bios, but emulating that a disk was already in the drive that does the same as DreamShell, since, without it, there'd be only the default bios which has no option to use the new gd-rom emulation features. xD

 

For media player it's about develloping an homebrew, there are media players for DC but not really advanced, why you want to play DVD or Divx on DC ? Every hardware can do it today ( smartphone, xbox, ps2... ), it will need a lot of work.

Let's focus on IDE interface first, i hope the compatibility will be better than the SD adapter.

 

As far as to WHY? To the DVD and other features I mentioned, you could do a case mod, create a shell that looks similar to Sega's DVD add-on that actually works. It would be a fun recreation to make, even though there's no real practical purpose.

But even without DVD playback, it's okay.

Speaking of that would it be possible to burn Dreamcast games to CD-RW, and DVD and play them through IDE Drives?


About IDE compatibility, it's actually replacing the GD-ROM so shouldn't there be 100% compatibility with faster read/write speed?

IS VMU emulation after GD-ROM emulation?

Sorry for so many question guys, I'm just a curious mind!

 

yep, theoretically possible to burn cd-rw or dvd-rw disc and play game from drive , but it's huge device, SD card is better. and no matter what device is used as the "source" - sd / hdd / dvd-rw drive, compabylity is same - depends on emulation algorythm of "fpga+mcu"

speed: theoretically it must be higher, for comparing see gd-rom speed ~ 1.3Mb/sec and speed from SD card or IDE device, i mean access speed to data. cause speed between gd-emu and DC is "constant" - depends on selected by DC tranfer mode ( DMA or PIO ) .

next i plan discover more about G2-bus and make devices like a BBA/Ethernet adaprtor, or another like "gd-emu" for playing games

VMU: - what you mean under emulation of such device? making copy of it or some of functions? i have idea make mem-card emulation for storing saves on SD card , or converter for using joystick from other consoles ps1/ps2/ps3/xbox360... by power of "gd-emu")))

 

you know i love ow we are talking about making a production level bord and pre orders
when we haven't even been able to boot past the liciance screen

and most of this can be done with a basic FPGA bord

 

So you're planning to use an SD to IDE Adapter?

 

angelwolf 71885 - we all work independently from each other, and as i know we have different skills in sphere of programming (fpga, mcu, win32 apps)

i dont wanna offer to ppl to buy "basic fpga board" and then send firmwares and instruction "how it must be wired" to them. if it be successful i plan make "ready-to-replacement" board... it is idea, so be patient.
even if i dont get good emulation of native "SPI" interface, there are still few ways how to get better results than sd-mod.
also this board helps launch test programs thruogh usb, so it canbe usefun for homebrew developers.

EmuSentai - "gd-emu" is adaptor itself acts like "G1-bus to SD",
G1-bus is close to IDE, so it can be called "IDE to SD" smart adaptor

 

http://s16.radikal.ru/i190/1302/5b/f999a69f0ee7.png

 

Nice work Cybdyn