[USB GDROM] Troubleshooting & Firmware updates

[dogeymon]

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

USB GDROM.jpg

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
FAT32.jpg
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!

Thank you for posting this.

[cbx]

I asked him for a changelog, he said no

I was hoping there would be compatibility fixes for USB 3.x thumb drives in the new firmware. Lost count on the number of USB 3.x thumb drives I have tried and never successfully got working.

Maybe there's some difference between board revisions but I never experienced such trouble.

I've been using mostly a Toshiba Canvio Basics (500 GB) USB HDD for years without issues but also a Transcend SDHC adapter and a Verbatim Store n Stay 64 GB stick. These are all USB 3.x devices. If you buy from Amazon or eBay it is not unlikely to receive counterfeit products. Storage adapters have been tampered with to pretend they have more storage than they can actually hold. Do some thorough tests with specialised tools or copy a couple of GB and verify it before trusting them. Also make sure they use FAT32 instead of exFAT as filesystem and use a MBR partition table instead of GPT.

Personally, I could never justify the extra price for a neat small stick or SDHC card over a HDD. The transfer speed is limited by the console anyway. Further, a 2.5 inch HDD is more robust and reliable than flash memory which has died on me before catastrophically without any warning.

[cbx]

in that case it will work, but it's complete crap, you need to wait 30-40 seconds each time before starting the game, plus it eats up the VMU resource

It's not crap at all but a priceless feature for free after years on top of a finished product. I takes only a little more than 20 seconds to load a complete VMU and 6 seconds to dump it. That's much faster than starting Dreamshell to achieve the same.

You can still use multiple physical VMU to swap save games instantly and since I usually play the same few games, there is no need to load a VMU from disk every time before starting it. Not to mention that all those loading screens take way more time.

I've put all games in their own folder and a 128 KiB VMU.bin into each folder. So I can store a whole VMU for each game and never have to worry about running out of VMU storage or overwriting them again. It also makes it very easy to copy all your games VMU state as backups, if you really care that much.

[peido]

I put together a little "quick patch" utility for USB-GDROM users who want to enable the VGA flag on their GDIs without having to extract/rebuild them.

viewtopic.php?t=17856

Hopefully it serves as a convenience for some of you

Note that this does nothing to apply "special patches" to the games listed here: https://consolemods.org/wiki/Dreamcast: ... nd_Patches

Nice, thanks.

[boquetipo]

Hi. Regarding my problem with Sports Jam, Mnemo asked me to sent him my board, and he sent me a new one. He seems to be unsympathetic in emails, but on the other hand, he is trustworthy.

As for now, I cannot tell if the problem persists, but I'm sure it's ok, since Xiden told me he had no problem at all.

Did your replacement unit arrive? Sports Jam is working fine here on latest firmware. I never tested it on older versions though.

Hey, sorry for late reply.

Sports Jam is not working in the last board, sent by Mnemo. I wrote to him about it, but never answered back.
I'm trying to find people in Spain (or Europe) that have the board. I found a couple of them, but I'm still waiting for their response.

[boquetipo]

Unfortunately, both persons that I contacted with, have problems with their SCART cables... Sigh.

I'll keep waiting, just in case they can get a new A/V cable.

[Teddy Rogers]

I'm trying to find people in Spain (or Europe) that have the board. I found a couple of them, but I'm still waiting for their response.

What board are you trying to find? I tested Sports Jam and it is working fine with my USB-GDROM.

I watched the video you posted on YouTube. Have you tried using a different AV cable? I think you may have an earth/ ground issue that is affecting operation of the controller. If you don't have another, check the pins in the AV connector are not pushed in too far and are able to make good contact...

https://consolemods.org/wiki/Dreamcast: ... or_Pinouts

Ted.

[boquetipo]

I'm trying to find people in Spain (or Europe) that have the board. I found a couple of them, but I'm still waiting for their response.

What board are you trying to find? I tested Sports Jam and it is working fine with my USB-GDROM.

I watched the video you posted on YouTube. Have you tried using a different AV cable? I think you may have an earth/ ground issue that is affecting operation of the controller. If you don't have another, check the pins in the AV connector are not pushed in too far and are able to make good contact...

https://consolemods.org/wiki/Dreamcast: ... or_Pinouts

Ted.

Hi. First of all, thank you for your time. I really appreciate it. Let me explain some things again:

- I'm not trying to find any board in particular, but someone that has the same problem I have.
- People from America have no problems with this game, AFAIK. Where do you live?
- Sports Jam IS THE ONLY GAME I have problems with, so far. I played several games, including Crazy Taxi and Cosmic Smash, that have (in my opinion) the same kind of boot, and all of them work properly.
- I also played Atomiswave games, and they work properly.
- I tested FOUR DIFFERENT DC (two modified, two unmodified). The only game with this problem is Sports Jam in all of them.
- I tested three different AV cables. The only game with this problem is Sports Jam in all of them.
- >>>>>>>> When I select the game, the DC logo animation starts. IF I PRESS START, IT WORKS, because the animations ends. So, THE CONTROLLER WORKS.
- >>>>>>>> When the game loads, during a moment the screen goes black. IF I PRESS START, IT WORKS, and the intro skips and the game flow goes to the main "press start" screen.
- You can check two previous tests here: https://www.youtube.com/watch?v=ilNiH7zTc0U (1:26).

I tried to follow your advice, and I will ask for another A/V cable.

Thanks again for your time.