USB-GDROM VGA Patched Bios PSA

[Syntax]

For awhile now i have been using Japanese cakes v1.032 bios with USB GDROM to bypass VGA checks and more.

Only problem is it causes the menu to glitch unless you boot with a normal bios then switch over to the jc-bootROM-v1.032 bios before loading a game.

I decided to update the firmware on my USB GDROM today even though the change log only stated a menu background color change.

Well, now jc-bootROM-v1.032 bios boots USB GDROM fine!

No more flicking switches or tricking games with different cables for me now.

Here's a little pack with the latest USB GDROM firmware and a fresh 2019 build of DreamShell which includes both Retail and DevKit Boot Bios.
Included is the jc-bootROM-v1.032 changelog.
You can choose to skip the boot logo and license screen for a quick boot into the USB-GDROM menu.

Spoiler

https://drive.google.com/file/d/1yUBCht ... sp=sharing

You need a dual boot bios or custom bios for this.

Just put the files on your USB/HDD and select via the USB GDROM menu.
Select "USB-GDROM_fw-18-04-18(O).bin"
After the update select "DreamShell_R4_2019.cdi"
Select "Bios Flasher"
Switch over to your custom bios now and select "Detect" to ensure everything is correct.
Select "Write" , navigate to the "sega" folder then select a jc-bootROM-v1.032.
Retail is normal boot sequence whilst DevKit is the developer one, there is no other difference. Its handy to know if your booting into a custom bios or not.
Confirm and sit back till its all done.

**EDIT**
Files have been updated to include more JCbootROM versions and the latest USB GDROM firmware.

[networkingyuppy]

This is awesome! I was wondering if you have the raw bin bios file so that I can flash it onto a chip.

[Syntax]

They are available in the Dreamshell source. Theres a whole bunch there, but the image I made has the older JC versions too now.

[citrus3000psi]

I'd like to try this. But I just read the newer firmware version have some type of self destruct timer built in. Requiring you to re-update.

[mikejmoffitt]

That's bizarre; is that only a feature of newer firmware? I have my old blue-background old firmware, so I hope that will not be a problem for me.

[Syntax]

I'd like to try this. But I just read the newer firmware version have some type of self destruct timer built in. Requiring you to re-update.

How can the new firmware have a timer in it requiring a reupdate when there isn't anything newer to update to?

MNEMOs site says dont update unless you really need the black background so I doubt any of this is true.

If you wanted to enforce something you would not suggest the alternative.
Nor would you put out buggy self destructing firmware that would be a PITA for customer warranty claims.

[Syntax]

Well eating my words...
Confirmed by the man himself the 2 current firmwares both include the time bomb. So I guess we are all in the same boat.


New non explodey firmware will be available when his next batch is shipped.

[Bratwurst]

Q: Why firmware-expired?

if GDEMU creator did same "firmware expiration" - his device will not been cloned.

Looks like anyone who bought one of these are in this indefinitely.

[citrus3000psi]

I'd like to try this. But I just read the newer firmware version have some type of self destruct timer built in. Requiring you to re-update.

How can the new firmware have a timer in it requiring a reupdate when there isn't anything newer to update to?

MNEMOs site says dont update unless you really need the black background so I doubt any of this is true.

If you wanted to enforce something you would not suggest the alternative.
Nor would you put out buggy self destructing firmware that would be a PITA for customer warranty claims.

I think the firmware you put on is something to just REARM the trigger, not newer firmware. Kind of how the GDEMU clone cannot be updated.

[Syntax]

REARM? They are all already armed, if anything the bios I've linked refreshes the countdown.

The linked firmware has an updated banlist(will ban/brick anyone's device that has their serial on the list, dont piss him off), black background and some other random tweaks that fix the menu glitch with jcvgabios.

[DejahThoris]

I'd like to try this. But I just read the newer firmware version have some type of self destruct timer built in. Requiring you to re-update.

He's already stated he's removing that method of protection end of June.

https://www.reddit.com/r/dreamcast/comm ... code_that/

[Bratwurst]

I don't see a battery on the USB-GDROM, and relying on the system clock of the Dreamcast itself would be sketchy since so many people go without replacing their cells and leave the calender on default. So this is just a guess, it's probably not battery/clock based but some sort of counter that tracks how many times it's been turned on/used.

[maxtherabbit]

REARM? They are all already armed, if anything the bios I've linked refreshes the countdown.

The linked firmware has an updated banlist(will ban/brick anyone's device that has their serial on the list, dont piss him off), black background and some other random tweaks that fix the menu glitch with jcvgabios.

I think he means "rearm" in the context of the windows trial activation thing - the thing stays armed but "rearming" it is just resetting the counter

[mario64]

Mnemo released an updated firmware today. Same release notes as before but hopefully it removes the expiration. Menu text is now white instead of green which I personally prefer

[Syntax]

He must of felt the heat lol.
I'll look into testing this and updating my link to be less volatile

[AndieDini]

Hi...If you wanted to enforce something you would not suggest the alternative.Nor would you put out buggy self destructing firmware that would be a PITA for customer warranty claims.

turnkey pcb assembly

[Xaranar]

Necroing. My USB GDROM won’t boot at all with version 1.032 installed. Works fine with version 1.031, however. With 1.032 it just hangs after the Dreamcast splash screen.

[Syntax]

Latest usbgdrom firmware?

[Xaranar]

Yup, everything up to date.

[Syntax]

If you used all the stuff in my pack then something is wrong.

With the latest USBGDrom firmware (Not the crappy black and green menu one) and latest JapCake bios everything should run fine.

Are you using a PICO PSU? DCHDMI?

[Xaranar]

I am using both a picoPSU and DCHDMI, but the problem existed before I used either of those. It's always been the case where version 1.032 does not play ball with my USB-GDROM. Yes, I have the firmware for USB-GDROM released 6/6/19 with the black and white text.

[Syntax]

If your PICO is wired off that tiny plug it will generally not be able to supply enough current for the DC and DCHDMI on the 3.3v rail and hang.

But your issue sounds like it's happening at the same spot each time.

So the older japcake bios works fine for you?
Flashing with the cdi in my pack?

I can only think of 1 more thing that might be an issue.

Is your vga cable wired to the correct MODE?


Also do this test for me, get a multimeter and set it to volts AC

Unplug the HDMI from you DC but leave it in your TV monitor.

Put 1 probe on the sheild of the HDMI cable, put the other probe on the DCHDMI HDMI sheild

Got any AC volts there?

[Xaranar]

If your PICO is wired off that tiny plug it will generally not be able to supply enough current for the DC and DCHDMI on the 3.3v rail and hang.

What do you mean? What tiny plug?

So the older japcake bios works fine for you?
Flashing with the cdi in my pack?

Yes, version 1.031 works perfectly fine.

Is your vga cable wired to the correct MODE?

Again, what do you mean? I'm not using a VGA cable, I'm using DCHDMI with the "force VGA" option on in the DCHDMI menu.

Also do this test for me, get a multimeter and set it to volts AC

Unplug the HDMI from you DC but leave it in your TV monitor.

Put 1 probe on the sheild of the HDMI cable, put the other probe on the DCHDMI HDMI sheild

Got any AC volts there?

I'll have to do this when I get home this evening, though I can't imagine why I would have AC coupling when there is no physical connection between the DC and my TV as you describe.

[Syntax]

Im outta ideas for you sorry.

Best of luck hunting down your issue, my system runs fine with those files I have provided.

[Xaranar]

Thanks, though I'm not holding my breath. Seems odd that one version would work fine whilst the other doesn't. Different board revisions to the USB-GDROM perhaps? Who knows. I might try putting my DCHDMI in cable detect mode and see if that makes any difference.

[Syntax]

Im using a VA0 DC if that helps anyone.
No DCHDMI, just a self made VGA cable with no buffer as I run into an Extron matrix which handles buffering and reclocking of the sync signals.

The DC analog output port has different jumpers to force it into modes, this may be your issue im not sure.

https://gamesx.com/wiki/doku.php?id=av:dreamcastav

[Xaranar]

DCHDMI is able to set the mode for output by itself as it connects to the VGA port jumpers. I have a VA1 DC, so maybe there is something in that as well, perhaps to do with the switch from 5V TTL to 3.3V. Your guess is as good as mine.

[evil_ash_xero]

Where would one even get the firmware now? It seems as his site is MIA.

And is the time bomb removed now?
Is it even worth updating, anyway? Were there games that didn't work correctly, or anything of that nature, in older firmware? I've had mine for a while. Before he put
the time bomb in the firmware. I'm kind of nervous about updating, but would do it, if it's "worth it".

[mario64]

Where would one even get the firmware now? It seems as his site is MIA.

And is the time bomb removed now?
Is it even worth updating, anyway? Were there games that didn't work correctly, or anything of that nature, in older firmware? I've had mine for a while. Before he put
the time bomb in the firmware. I'm kind of nervous about updating, but would do it, if it's "worth it".

http://3do-mnemo.com/USB-GDROM_Controller.htm

[evil_ash_xero]

Where would one even get the firmware now? It seems as his site is MIA.

And is the time bomb removed now?
Is it even worth updating, anyway? Were there games that didn't work correctly, or anything of that nature, in older firmware? I've had mine for a while. Before he put
the time bomb in the firmware. I'm kind of nervous about updating, but would do it, if it's "worth it".

http://3do-mnemo.com/USB-GDROM_Controller.htm

Thanks. I don't know if I trust the guy to have taken the time bomb out. Can anyone confirm it?