Dreamcast-Talk.com

Hello all,

I had some troubles from time to time with my USB GDROM from MNEMO but always find a way to resolve them with the help from some others.
So here we go with some information:

Latest firmware: firmware update v 2019/06/06 - Which removes the "Time-Bomb" - Thanks Xiden for the information!
But you can also view the older and hotfix firmwares on Google Drive Archive
Latest hotfix: fw-18-04-18(O)

The USB GDROM is a mod created by MNEMO.
With his mod it is possible to load GDI's, ISO's and CDI's from a USB storage device.
From MNEMO's website
Description/Features:

- USB 2.0 Host
- any USB media up to 2 TBytes: USB Flashstick, USB HDD, USB-SD
- FAT32 (long file names supported)
- unlimited sub-directories with any names
- 100% compatible (about 600 games was tested by DC community)
- CDDA implemented
- Images: GDI, ISO, cdi
- «Region free» can be ON or OFF (you can launch any GDI images(NTSC/PAL/JP/EU/US) at your console)
- flexible «Swap Image» feature
- compatible with VA0 & VA1 model (all consoles with GDROM connector. VA2 has integrated GDROM Controller)


Installing the USB GDROM



So basically you replace your laserunit with the USB GDROM mod.
The first version of the USB GDROM had a external USB port which neede some cutting in the Dreamcast casing.

Installing the USB GDROM is pretty easy, the only soldering needed is for placing the lid switch on the new USB GDROM board.
This is needed if you play multidisc games or want to use things like codebreaker.
Xiden has a nice post about how to do this already here on Dreamcast-Talk.
At the moment you can buy the board with the lidswitch preinstalled!
Though this should also be possible with a button combination.
When use Button as Lid switch - Put this file to USB (I have not tested this yet)


Preparing your USB storage

To get your USB drive working you will need to format it in FAT32 with 64k clusters.
MNEMO provided me with a tool that runs on Windows: fat32formater Be sure to format your device with 64k clusters!
Most problems with not booting games is caused by not having the right FAT32 64K cluster format.

After the format is ready you need to download root_init.rar and unzip it on the root of your USB Drive.
The folder can be handy for putting games in it but if you want to organize different it is up to you, just be sure Launch DASHBOARD.iso is located on your USB device in the root folder.


Upgrade the Firmware

To upgrade the firmware visit MNEMO's website: http://3do-mnemo.com/USB-GDROM_Controller.htm
Download the latest firmware and unzip it.
Copy the USB-GD_fw_**-**-**0.bin to the root of your USB device.
Boot your Dreamcast and select the upgrade file in the menu and open it.
Upgrade will start, please don't turn of the system!
After the upgrade is done the system reboots.


Electrical mods to reduce heat
When you have installed your USB GDROM mod your Dreamcast loses the GD-ROM unit that uses the 12V .
This causes the PSU to heat up.
I tried gaming with it for serval hours without issues but it did get really hot.
So I tried putting in a resistor on the 12V pins and it works pretty well for me.
It still get's hot but not as insane as the first time.

I used a 300 Ohm 1/4W resistor like in the video above (Starting at 1:40).

Another possibility is replacing the PSU with a PicoPSU.
This option is probably the best option to get things fixed but it requires some more work.

A PicoPSU 60watt will do, more is just overkill from what I have read.


Buying the USB GDROM
So you are interested buying a USB GDROM from MNEMO?
Go to his website: http://3do-mnemo.com//How_to_buy.htm
Use his order form (please note paypal only).
MNEMO is trustworthy so please be patient about the responds from MNEMO.
It sounds sketchy but a lot of people received their USB GDROM without any problems.


Handy links
Thanks to Xiden:
Wanted to add the following usb gdrom items
Both these auctions have ended but if you emal the seller collingall2005 on ebay he will likely sell you a kit.

Installl guide https://m.imgur.com/a/WcHjT

A usb gdrom bay insert
http://m.ebay.com/itm/272678068291

Here it is on thingverse
https://www.thingiverse.com/thing:2302737

Fan mod - It is specifically built for the Noctua NF-A4x10 5V fan
http://m.ebay.com/itm/Dreamcast-silent- ... HING_ENDED

Here it is on thingverse
https://www.thingiverse.com/thing:2308549

PicoPsu mount
https://www.thingiverse.com/thing:2308511


Troubleshooting

• CDI's work but GDI's won't load - If after update GDI Images not working-that means you need also additional update. https://yadi.sk/d/bjF1gxE7rFQt2
• Games won't load but the menu starts - Reformat your device with FAT32 and 64 clusters
• The Dreamcast heats up - Check out above for a Resistor mod or PicoPSU mod.
• USB GDROM won't work correctly, sometimes not booting and/or loading games - This can be caused by a bad DC internal battery

MNEMO's own support guide:

USB-GDROM Tech guide
If your device working bad or not working: http://3do-mnemo.com//USB-GD_Tech_guide.htm

1) format USB with cluster size 32k or 64k
2) Try different USB Flashstiks
3) Clean Power connector of console (6 pins)
I clean it every 3 month else USB-GDROM and GDEMU working bad or sometimes not working at all.
(if you are too lazy- just reconnect Power Supply few times.)
4) Try another console

Thanks Xiden for all the extra information! (again!)

Any extra information is appreciated!

Exellent guide You should PM Impulse to add to it his list of guides. This is the kind of information that needs to be imortalized.

Thanks!
Tomorrow I will update the post with the heating issues.
I will add the picopsu and the ressistor option

Wanted to add the following usb gdrom items
Both these auctions have ended but if you emal the seller collingall2005 on ebay he will likely sell you a kit.

Installl guide https://m.imgur.com/a/WcHjT

A usb gdrom bay insert
http://m.ebay.com/itm/272678068291

Here it is on thingverse
https://www.thingiverse.com/thing:2302737

Fan mod - It is specifically built for the Noctua NF-A4x10 5V fan
http://m.ebay.com/itm/Dreamcast-silent- ... HING_ENDED

Here it is on thingverse
https://www.thingiverse.com/thing:2308549

PicoPsu mount
https://www.thingiverse.com/thing:2308511

Again thank Xiden!
That PicoPSU mount... want it!

RXShorty wrote:Again thank Xiden!
That PicoPSU mount... want it!

MNEMO E-mailed with a guide he created just recently I guess? I told him we'd add to to our guide

http://3do-renovation.ru/USB-GD_Tech_guide.htm

Done

Hello. I just receive my USB GDROM and I mount it and everything. It loads CDI images perfect, but when I tried to load GDI it won't boot the game, it just boot again to the GDROM interface =/ Anyone know what is happening?
Thanks in advance.

Hello guerra,

Mostly these problems happen when you USB storage device isnt correctly formatted.
Please format it FAT32 with 64k cluster see the how to above

something else to note. Hard drive partition must be set to MBR or it will not boot either. I know this program can change it.

http://download.cnet.com/MiniAide-Fat32 ... 01815.html

1. Use FAT32
2. Use 64 Clusters.
3. Make sure that hard drive partition is MBR