Devkit Boot-Intro for Retail-Dreamcast?

Its boots any region GD-ROM's and CD-R's, but GD-Rs have not yet been tested as l_oliveira does not own any. When I get my chips I will test if GD-R's work (Unless somebody beats me to it!) but id work on the assumption that they wont work, and then be pleasantly surprised if they do...

...If we really cant get GD-R's to boot on a retail system (or you have to choose between Mil-CD or GD-R support) then you could always perform the GD-R boot 'switch mod' shown on these very forums some years ago, theres a guide for that somewhere around here...

 

After some testings i can not make the katana boot CD-Rs Since i have made two modifications : Free region works great, and cd-r tentative( it reboots like the real dreamcast when you put a mil-cd) Others modifications cause the katana cannot be booted : an error in da check show me that DA have no serial, i can recover from this by booting from the recovery chip (switch 4 enabled) and reflash the original bootrom

 

Hi Evangelion,
Do you mean you have tested this new modifed bios on your HKT-0120, or are you discussing your own attempts to modify the HKT-0120 bios? Did you test GD-R's aswell?

Please bear in mind my intention was to make this bios work on a retail Dreamcast, if it works on a HKT-0120 aswell then that would just be the icing on the cake :dance:

 

I'd guess the gd-r gd-rom discrimination is done in the gd-rom reader firmware as its the gd-rom that read the "security ring". Thus link83's bios shouldn't works with gd-r on a retail DC but it shall works on the devkit. This would prove my hypothesis.

However evangelion, you should find a guide on how to boot non-selfboot games on cd-r on a katana on this site. I developped the technique and mark30001 tested it out. It works well!!


FG

 

I know how to do it with the utopia boot loader.

 

You might want to check this out: http://www.assemblergames.com/forums/showpost.php?p=337863&postcount=11

P.S. Yes it is also very likely the gd-r check is firmware related, but it could be that even the devkit drive has the security and that only a couple of registers which the bios (or in retail the system disc2) set to disable it.
After all, the retail does read mil-cds (which all lack the infamous security ring)

 

Retails read the mil-cd because this format was designed to work on the DC; some weird japanese multimedia-cd were genuine mil-cd. However some smartasses found a way to enable the gd-rom access in mil-cd mod and them the console was cracked open.

However I truly beleive that the devkit doesn't do a ring check at all. I guess it simply goes to 45000 and look for a ip.bin and boot according to it. At least it's how I'd have made a devkit bios. AFAIK gd-r are burnt gd-rom without ring, that's the only difference.

Regarding your other post, I cannot remember who tell that back in the days, so don't quote me on that, but someone said the SystemDisc2 had a "special" ring...

Maybe the problem also simply apear because you're bootin g the systemdisc2 on a mil-cd then trying to boot a gd-r ...

If the problem really is the ring check (and not a well-hidden non-ring-related check) a "modchip" to run gd-r would be feasible. Just like the Saturn modchip input the data the saturn drive should read when looking for the ring regardless of the disc inserted.

Regards,

FG

 

I would be interested in this BIOS file.
Pleas pm link.
Thanks

 

Please send me this bios file, i'll write a chip and test it on one of my Dreamcasts

THANKS (i sent you a pm)

 

I doubt the dev kit looks in the bios for the region settings, that is what the switches are for. Someone just needs to find where it reads them.

 

strage, the emulator crashed with this bios...

 

Ok, this topic was long, technical and I'm very tired. What is the bottom line? Is it possible to put the devkit bios on a retail DC?

 

A mixed bios can be put on a retail DC, get it from link83

 

I want to try this. Putting the mixed BIOS on a retail DC, that is. I have a powerful Dataman programmer and SMT tools at work. But I can't find the AM29LV160 chips (or an equivalent) anywhere. Any of you guys know where to get those?

 

Anyone?

 

You can get them from some china electronic parts retaillers, but, it's very risky.

Also, AM29LV160 is not anymore produced by AMD.

 

Why is it risky to order in china?

here is a link to a shop in Spain which has the chips but the have some more types, i belive with different speed.
Which one we would need?
http://www.diselec-electronica.com/...r=diselec&part=AM29LV160&Submit1=Start+Search

 

How easy would it be to flash my dreamcasts bios? i'm guessing i need a programmer or possibly have to soldier the motherboard.

I'm also guessing i'd need to buy a chip to get it to work?

Btw fantastic work guys, i love the new BIOS animation

 

The original BIOS can't be reprogrammed since it's on a ROM (read only memory). It's possible to add a new chip over the existing one, so a new ROM and some soldering are needed.

 

i now have a programmer now all i need is adaptor for that chip i dont know what chip to use i know its smd my programmer is top2004.