GD-ROM Dumping Guide

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Revision as of 20:39, 30 May 2018

This is a step-by-step guide designed to be easy to follow so that you can make reproducible, good dumps of your GDs to the Redump standard.

What are GDs?

GDs—or Gigadiscs—are the type of optical media used by the Sega Dreamcast as well as the Sega NAOMI, Sega NAOMI 2, Sega Chihiro and Triforce arcade systems. It is special compared to its relative—the CD—in that it contains both a low density (LD) and a high density (HD) area. To get a good dump, you need to extract them both from the disc.

If you have any of the officially released discs for the Dreamcast or any of the above mentioned arcade systems, you are pretty much guaranteed to have a GD. The Dreamcast did however support loading of MIL-CDs, which lead to a number of unlicensed software being pressed on regular CDs. Check for the GD-ROM logo on the disc or check the reflective side of the disc for a visible LD–HD divide if you are unsure.

Tools

First you need to make sure you have the necessary equipment. To dump a GD you need:

• A Windows PC
• Compatible drive(s)
• A Pin or Paperclip for the disc ejection hole on the Disc Drive
• DiscImageCreator app
• Create an Audio Trap Disc:
  1. Get a blank CD-R or CD-RW disc
  2. Download this free burning app: CloneCD (CDmage and Alcohol 120% also work)
  3. Burn this disc image to the CD-R/RW

Dumping the LD area

This is the easy part. Make sure you have a compatible drive with the latest firmware and have downloaded DiscImageCreator.

1. Open up the folder where you downloaded DiscImageCreator (DIC).
2. Extract the DIC zip into a new folder.
3. Enter the folder in which you extracted DIC and open the Release_ANSI folder.
4. Hold Shift and right-click anywhere in the folder. Select Open PowerShell window here from the drop-down menu.
5. Make a mental note of how the DIC commandline looks. The general command is .\DiscImageCreator.exe cd d "DumpFolder\DumpName.bin" 8 /c2 where the green text indicates that it is a CD we're dumping (which is what we want for the LD area, so leave it as cd), the red text indicates which drive letter your drive has (in this case it's located at D:\) and the blue text indicates the drive speed (here it's set at eight times the speed.)
6. Now type in the command that is relevant to your disc into the command window you opened before. For example, if you were to dump a copy of DreamKey from drive F:\, the command would be something like .\DiscImageCreator.exe cd f "DreamKey\DreamKeyLDA.bin" 8 /c2.
7. Press Enter and the dumping will begin.
8. After a while the dump should be finished and you can move on to dumping the HD area.

Dumping the HD area

• Insert the audio Trap Disc to a compatible drive.
• run below. (stop spinning disc) DiscImageCreator.exe stop [DriveLetter]
• use a pin to press the escape eject button, so the tray will eject (or remove the drive cover).
• insert the gdrom and gently push the tray back (or put the drive cover back on).
• run below. (start rippping gdrom) DiscImageCreator.exe gd [DriveLetter] foo.bin [DriveSpeed(0-72)]
• The only error saved from the _mainError.txt file is this one:
  • • LBA[045000, 0x0afc8]: [F:ExecSearchingOffset][L:110]
    • Opcode: 0xbe
    • ScsiStatus: 0x02 = CHECK_CONDITION
    • SenseData Key-Asc-Ascq: 05-24-00 = ILLEGAL_REQUEST - INVALID FIELD IN CDB
  • lpCmd: be, 04, 00, 00, af, c8, 00, 00, 01, f8, 04, 00
  • dwBufSize: 2448

Submitting your dump info

Compatible drives

GDs are strange in that they contain two distinctly different areas of data. What this means to you is that you will have to dump the disc's LD and HD area separately. Unfortunately, this also means that you will need special hardware.

For dumping the LD area, the same rules apply as in dumping a CD, as they use the same technology. A list of compatible drives for dumping LD area is found below (and a more up-to-date list can be found in the CD Dumping Guide.)

But for the HD area the process is different, and you need one of the following drives to dump it: