MetalliC
Champion
it is in MAME romset for many years
Burn NAOMI games to CD-R and Play on GDROM Drive?
- Thread starter RealMFnG
- Start date
Finisterre
Professional
I'd say - there was no interested enough person, who have skills to hack DIMM firmware, and wants CD support added
there only hacked 4.01 with CF vendor check disabled, which people call "4.02"
Always fun connecting dots and trails of bits around here... (forgive the awful translation):
"In the Internet there are rumors about the existence of hack firmware DIMM-board version 3.17 with support for reading CD-ROM. The author is ElSemi."
...
"it's private, you can not look. although you can try asking around for arcade-projects"
...
"this hack (the essence - a patch of 2 bytes in the firmware) is available only for a circle of persons who himself was engaged or is engaged in research of Segov DIMM, which can be counted on the fingers of one hand. until Elsemi himself decides to make this hack public - no one else, myself included, will do it himself."
from: https://www.emu-land.net/forum/index.php?topic=78927.0
I'm gonna guess it is not a fruitful thing to *ask around* here as it were? Anyone else mess with this, that is outside of the inner circle as it were?
J
jassin000
I haven't messed around with Naomi, but back in the Dreamcast days I did a lot of work with ripping/downsampling/burning on CD-R.
I don't know how much of a problem it would be for Naomi, but Dreamcast games often used resources like sound or video to completely fill the space on the GD-ROM.
GD being Gigabyte Disc it held more data by setting the packet spacing closer together in the High Density track area (which is often times track 3 but can include others).
It made downsampling resources necessary as without the ability to write HD tracks you are capped at 700mb max.
As you can imagine some CD-R reproductions were actually perfect, because they never used the entire 1GB space anyway.
But for the games that did, the CD-R reproductions sucked to put it mildly (and its not worth the effort involved).
I don't know how much of a problem it would be for Naomi, but Dreamcast games often used resources like sound or video to completely fill the space on the GD-ROM.
GD being Gigabyte Disc it held more data by setting the packet spacing closer together in the High Density track area (which is often times track 3 but can include others).
It made downsampling resources necessary as without the ability to write HD tracks you are capped at 700mb max.
As you can imagine some CD-R reproductions were actually perfect, because they never used the entire 1GB space anyway.
But for the games that did, the CD-R reproductions sucked to put it mildly (and its not worth the effort involved).
MetalliC
Champion
true, but there was unsolved side effects like reset after some time, which makes in ususable at practice, so that hack was abandoned in prior of CF or Net boot methods.
I also tested some CD-R hacks we wanted to try but they didn't work. This was a year or two ago. It was abandoned very shortly after. I mean, CD-Rs suck anyway.
That's good?
So basically it needs further patching, right? Any clue about what could trigger it? Another GDRom check? Timing issues?
From what I know there was an additional media check after 1 hour.
Anyway this track is dead, no point in using a CD-R which has less capacity than a GD-ROM when we have the CF solution.
That reset was patched in the CF version. I guess it can also be easily patched in the GDRom version, if the code that does the check is similar or jumps to similar positions for reset, etc.
I agree that CF is better, but the good thing of using CDR is that you can also have that option and games take in most cases less than 256Mb. Also GDRoms are hard and expensive to find, not to mention that it's not available for everyone to burn them.
I agree that CF is better, but the good thing of using CDR is that you can also have that option and games take in most cases less than 256Mb. Also GDRoms are hard and expensive to find, not to mention that it's not available for everyone to burn them.
J
jassin000
I'm a little surprised no one has tried to adapt the GDEmu device to Naomi.
If the Chinese can clone it, I'm sure you could hackup the original/official firmware to make it work.
*update* Oh I guess it would need some type of adapter and voltage regulator board as well.
J
jassin000
I said the Chinese cloned it... I was suggesting you make the adapter PCB and a custom firmware to use a real GDEmu on a Naomi. 
Finisterre
Professional
To be fair... this is a subjective opinion. Considering most Naomi1 or Naomi2 games hover around 240M in size, topping out at 459M for Virtua Striker. Same for Chihiro games in many cases. Wangan comes in at 485M.
From a cost perspective, 128 CD's will cost significantly less than 128 CF cards assuming you wanted to maintain a single copy of each game per card.
Likewise the CF solutions are quite the investment up front to play along. Mind you of course some folks have invested in reproducing hardware, I can see why they may feel one way vs. another.
I'm less interested in the subjective nature of everyones opine on relevancy and more interested in the technical limitation that very well may be bypassed IF we put our heads together.
Finisterre
Professional
from a preservation standpoint it is nice to have many options / choices.
J
jassin000
IMO CF is dead storage media, just like CD-R.
microSD media or GTFO.
*Gasp* Is this the beginning of the official Naomi "multi" announcement!!!!!!!!1
You would not need to clone anything the GD-ROM uses the same connector.
However the GD-ROM system is 5V but the GD-EMU 3V3 so I would not recommend that
CD-Rs are dead, slow, unreliable and this is the reason SEGA made the CF solution.
MetalliC
Champion
right, there is probably some kind of scheduled checks, iirc there is PIC check routine, and disk presence check routine, but I have no good ideas why it may not work for CD-R.
to be fair... @rtw is examined GD images from Naomi/Chihiro/Triforce and know how many data written on.
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