Freezing after bios installation

[olleulv]

Hi,

I just got a Dreamcast with modded bios, sd-card, vga-mod.
I installed Dreamshell to the bios, tested some applications and decided to go back to "normal".

So.. I uninstalled Dreamshell from bios...

Now the system freezes whn reading any disc... doesn't matter if it's an audio cd or an original DC-game... or homebrew...

Anyone got a clue?

[SWAT]

You must have a switch on the original bios. Switch back to the original bios, load DS, switch back to the modified bios and flashing using a file manager other bios (just click on the file . bios 2 times).

This was due to the fact that with uninstall of DS, flashing the bios from DevBox, without a hack. It does not work on normal DC. This is my error, sorry, I forgot about it
I corrected this in the new version of DS.

[olleulv]

ok... how do you mean.. switch? physical on motherboardor in the software? I haven't seen any.... I have one physical external switch for VGA/AV....

Sorry if I suck....

[olleulv]

(21.04.2011 17:12)olleulv писал(а):  ok... how do you mean.. switch? physical on motherboardor in the software? I haven't seen any.... I have one physical external switch for VGA/AV....

I understand most of what you said... except how to get back to original bios without cd?

Sorry if I suck....

[lolof]

Normaly, you should have a physical switch somewhere on the case or maybe inside the case.
This switch has to be used to choose on the bios you want to boot in.
You have to find this switch and toogle it and after your dc will boot in the original bios.
For this operation you do not need the dreamshell disc, you will need it if you want to flash the bios in the second chip, the one who is soldered on the original one.
If you cannot find the switch, you should open the dreamcast and look for the extra chip or the switch.

[olleulv]

Thanks for your answer.
I havent located any switch.. but i have located the chip on the motherboard. Släp some wires from it. Whats my next step? Its useless without the ability to read discs.

Thanks again

[lolof]

Do you see the soldered chip on the original one ?
Maybe the man who made the mod on your dreamcast didnt put a switch....
Maybe it is only wired. 2 wires must be put together to give access to the soldered chip and one wire must be remain alone. One of the 2 that are actually together should be connected to the remain one. You should better learn how this is build from here and find the good wires that have to be put together to give access to the original bios chip.

Read this thread, you will find Useful info :
http://www.assemblergames.com/forums/sho...hp?t=24880

Here the shematic :
http://www.dc-swat.ru/blog/hardware/16.html

Now, you can see that the wire who is coming from the leg 12 of the Soldered bios chip is put together with the wire soldered on the D501, you have to separate those 2 wires.
Then you should link the wire that come from the leg 12 from the original bios chip with the wire that is soldered on the D501 component.

If it works, you should put a on/on switch, it makes life easier.

If you cannot do it after reading those links, maybe we cann help you if you post some photos...

Good luck

[olleulv]

thanks! really appreciate your help!
I'll look in to it and get back to you.
I'm uploading a picture here.

http://www.picupload.us/images/imag0191.jpg

[lolof]

I think it will be more complicate.....

Its looks like the original bios chip has been removed if i good see on the photo. if I am not wrong, you are not able to switch to the original bios!

It should normally be 2 chip, one on the other one, like the photo on the 2nd link i posted you before.
It seems that you will need a chip with a pre programed dc bios and that you will have to solder it yourself to get your dc to boot again!
Its a pity that the original bios chip has been removed!

Let see what mr. swat think about this.

[olleulv]

ok... I can confirm that it's one chip only...

Would it be easier for me to just go back to normal bios somehow?

[SWAT]

It is bad and I do not understand why. The scheme is designed to work with 2 bios, the second just soldered on top.
This is intentional, since the BIOS firmware dangerous occupation, always have a chance to damage it.
If you had 2 bios, then you easy to switch them.

[lolof]

Without a new chip with the dreamcast bios your dreamcast will not boot.
At the moment, you have no bios in your dreamcast, it means no possibility to boot nor to programme a new bios chip from your dreamcast. You have to solder a new chip with pre programmed bios in your dreamcast. It is the only way to get your dreamcast to boot again.
You could also take this one out and ask someone to programme it for you and solder it back to your dc.
It is crazy to have removed the original one.

[olleulv]

OK...My Dreamcast does boot though. It freezes when inserting disc.

[olleulv]

So,... any new thoughts?
Or does anyone know where to get a new prepared chip?

I've contacted the seller.. but got no response.

Cheers!

[SWAT]

No luck
You basically do not necessarily to get the same chip, you can take orig bios, or vice versa to solder this chip on another motherboard.

[olleulv]

OK.
One last question...
I've got a japanese dc-motherboard here. can I take the orig bios from it and replace the flashed defect one?

[SWAT]

Yes, why not. Just check the bios they were working on the same voltage.