Possible ways to read GD-Roms on a PC?

Thanks, that really does help :nod:

I now think I understand what the two bin files are for - they are needed if you are making a GDX upgrade disk on a GD-R
v147c_HD.bin is for the 'high density' area
v147c_SD.bin is for the 'standard density' area

You dont need them if you are making an upgrade disk on a CDR, but instead you need to make a file called 'padding.bin' lasting 40 minutes. Also, with a CDR I dont think you can upgrade a GDX from any version firmware - it has to be the previous version. With a GDR firmware disk I think you can upgrade the GDX from any version firmware.

I wonder if the GDX firmware is the same/similar to the GD-Rom drive firmware? Maybe I should try using the firmware upgrade disk on a Dreamcast console?

The GDM sounds very interesting too - if it mimicks a GD-Rom drive but allows a Hard Drive to be connected instead I wonder if it could be used on an actual Dreamcast console to connect up a hard drive to replace the GD-Rom drive? h:

Obviously its very limited in how many people could try this, but if it did work and we could gather enough interest perhaps we could replicate the GDM board?

No worries. If you could take a look that would be great :icon_bigg

 

Well I just thought id update that I have just recieved a Yamaha CDR-400T and a Yamaha 4260 - I choose these two drives as the Yamaha CDR-200, CDR-400, CDR-2260 and CDR-4260 all use the exact same firmware. I have been experimenting - so far without much success.

I have just tried flashing the CDR-400 drive with the GD-Writer firmware, and under the Adaptec Bios it now says 'Device Name Not Available' and it no longer shows as a drive under Windows XP :shrug: Now im not too worried about this as it was very cheap, and im pretty sure that I can reflash it back under dos.

However im curious as to why some peoples CDR-400T drive identifies itself as a 'SEGA GDR 1999' after the flash, where as mine doesnt?

I took out the mainboards from both the CDR-400 and the CDR-4260 drives to compare them, and surprisingly they are almost identical! There is only one difference I can see - one 3.3k resistor.

Now having looked this up online I have seen that it is possible to convert certain revisions of the CDR-200 into a CDR-400 by removing one resistor:-
http://www.cdmediaworld.com/hardware/cdrom/cd_modifications_yamaha_200.shtml

So what im thinking is that the 2260, 4260, 200 and 400 at certain points in production (around 1998) all used the same motherboard, with just a resistor in a different position in order to identify the drive name - otherwise there would be nothing at all to tell the PC what drive it was, as they all use the exact same firmware as previously mentioned - so the firmware wouldnt help identify it (as modern drives do)

So, what I would REALLY like to know is whats the code and revision for the motherboard used in the GD-Writer? (My CDR-400's motherboard is marked XT948 and is revision 'C') Also what positions are the resistors in? For reference circled in red on this picture is the location of the resistor on the CDR-400 (Sorry for the blur):-


There is two resistors on the 4260. I have a feeling that the two 'RESERVED' locations will have something to do with the GD writer.

All I really need is scans of the motherboard from a GD Writer (HKT-0400)SegaKatana.com used to have them, but the sites been down for a long time now :crying:

 

Actually, if your profile is correct, no it isn't legal to take a backup in the UK. You can take a backup of DESTRUCTIBLE media. CDs and GD-ROMs are media which do not make contact with heads, making them non-destructible. Therefore, it is NOT legal to make backups of CDs. I wish people would stop misquoting the law on this!!!

Anyway, good luck with your quest. I won't suggest that perhaps it would be easier to go for the grey area and download images of said legally-owned titles....

 

Well, I was going off this:-
http://worldofstuart.excellentcontent.com/world/pczone/backed.htm
Is this wrong then?

As I said previously - im not looking to pirate a load of games (There would be little point anyway, as almost all Dreamcast games are available for download now for anybody that would want them) Im simply trying to do it for the curiosity and the knowledge, and the abilty to look at the 'version numbers' of the games I own.

I dont agree with piracy at all, but having backups of your own legitimate games for personal use on a dead system hardly seems that bad to me, or is it just me that feels that way?

 

http://rapidshare.com/files/150394350/Sega_Katana_HKT-0400_GD-Writer_SECRET_SWITCHES_.rar.html

Here's all the pics of a htk-400 i could find on my computer, if it can help. I also own a cdr400t and it flashed correctly to a gd-r and displayed the gd-r name: SEGA GDR 199. I could even flash it using the windows based gd-writer flashed and any firmware (gd-r 1997/1999 or Yamaha).

I dunno what went wrong with yours ...

FG

 

Thanks very much for the pictures familyguy :icon_bigg They really are intriguing. Out of interest do you know what revision mainboard your CDR-400 has, or could you tell me when it was made? (The date is printed on the top sticker) I can only assume your CDR-400 has a different revision motherboard to mine - I know there were at least 3 revisions of the CDR-400 - Mines a 'C', and I have seen pictures of the 'B' revision online. I formatted a spare hard drive and installed Windows 98 to see if my CDR-400 would be identified, but it still doesnt show up as a drive - I wonder why yours does?

On one of those picture I can make out the chip which has the resistors right next to it - I just wish it was clearer/closer so I could see where the resistors are :crying: Ive circled it in red on this pic:-

I dont want to seem like im mithering, but would anyone with a GD-Writer be willing to take a picture/scan of the mainboard? (and daughterboard if you can)

I can also see that the GD-Writer does seems to have some extra hardware that the CDR-400 doesnt, weather or not this would make a difference to our success I dont know. From what I can see though its interesting that alot of the components on the daughterboard of the GD-Writer have been 'condensed' into the one mainboard on my CDR-400.

It almost looks like the GD-Writer is two drives combined into one - is this the case I wonder? Does it have two lasers? (guessing by the ribbon cables here) Perhaps one writer and one reader?

Also the separate daughterboard 'almost' looks like the GD-Rom board from a Dreamcast console, which has got me thinking - I wonder if I could use the CDR-400 mainboard to connect up an actual Dreamcast GD-Rom assembly to a PC? The reason I think this 'may' be possible is that on the CDR-400 board are soldering points for a 100 pin header. Now I know that the GD-Rom board has a 50 pin header. I'm just guessing here but if this is the case the main issue would be working out which pin goes where, and which ones are unused. Heres a picture showing the two connectors, CDR-400 on the left and Dreamcast GD-Rom board connector on the right:-


Now on the GD-Writer there is a large ribbon cable connecting the two boards - im guessing that this is a 50 wire ribbon cable? If I could see which pins this cable connected to on the GD Writers mainboard I would have a go at connecting them myself!

Also, on my CDR-400 there is three adjustable pots - just like on the daughterboard of the GD-Writer.Heres a pic:-


I wonder if they serve the same purpose? Id love to try and tweak them to see if I could get it to 'read' GD-Roms like the GD-Writer (I know that it usually kills GD-Writers when you mess with these pots, but im willing to risk a CDR-400) but with it no longer identifiing itself as a drive I cant really try it at the moment :-(

 

My cdr400t is a CDR-400t-NB manufactured JUNE 1997

My guess is that you did a bad flash.
Try to connect the gdr400 to the scsi cable and run this command

dld_dos.exe scsicom.bin X 0 11000

Where scsicom.bin is a real cdr400 flash file, and X the number of the scsi device (based on jumpers on the back, look for the pdf manual of the cdr400 to see how to choose the ID.

I might open it up later if you want.

Also, gd-writer can't read gd-r at all. LEGIT says he suceeded once, but then fried his hkt-400. Mark also fried his one this way.

FG