GD-ROM Dumping Guide

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Revision as of 22:17, 5 December 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)
• DiscImageCreator app
• Download VGPC GD-Rom Dumping Kit (audio trap disc image, dcdumper, ice, startstop)

Burning an Audio Trap Disc

You'll need an Audio Trap Disc for the HD Area dumping process as it tricks your drive into reading into that part of the disc.

1. Get a blank CD-R or CD-RW disc
2. Download this free-trial burning app: CloneCD (CDmage and Alcohol 120% also work)
3. Burn this disc image to the CD-R/RW

The Audio Trap Disc image is included with the VGPC GD-Rom Dumping Kit. Because the image intentionally has errors, many programs won’t burn it properly. We’ve found that CloneCD can reliably burn it properly:

• Open Clone CD and click on “Write from ImageFile”.
• Click on “Browse” and navigate to where you extracted the VGPC GD-Rom Dumping Kit, and select “TOC122A.CCD”.
• Then, select the drive with the blank CD-R(W) inside. Click on the “Protected PC Game” profile. The write speed doesn’t matter much since this is such a small image. Still, you should probably avoid setting it too fast or too slow. Somewhere between 4x and 24x should be good, so set it to 8x if you don’t want to overthink.

Dumping the LD Area

The LD Area should be dumped with DICUI using this guide: Disc Dumping Guide (DICUI).

The LD Area is a standard CD-Rom, so it will be the only data to appear when mounted in a computer.

Dumping the HD area

• Insert the audio Trap Disc to an HD Area 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