Dreamcast Devbox Bios on retail Console!

[angelwolf71885]

The "flashrom" chip he references is not the BIOS chip. All BIOS chips are 2mb in size. The flashrom referenced is normally 128kb but some are 256kb.

The flashrom being that which stores region data and the PSO ver2 serial number amongst other items. As such you can't modify existing Dreamcasts to flash a new BIOS onto as the BIOS chip is mask rom and not writable.

Even if you could write a BIOS to the flashrom and have it bootable the BIOSes available are all 2mb, not 128kb or 256kb.

ah i see never mind then lol

[docentore]

I'm wondering if M27C160 eprom chip would work? I think I have few of them.

Thanks!

[H360]

Why are all the hackers Russian? :shrug:

[alphagamer]

Why are all the hackers Russian? :shrug:

Because they are very ambitious people?

I know quite a few talented russian programmers, they never seem to give up on a problem.

[UprightCarrot]

This mod hates me my working DC now freezes on retail splash.
And my corrupted region DC now has dev splash and boots some GD's but no CD-r.

Guess my soldering sucks :lol:

[APE]

This mod hates me my working DC now freezes on retail splash.
And my corrupted region DC now has dev splash and boots some GD's but no CD-r.

Guess my soldering sucks :lol:

Best left to we professionals. Even if the flash were to become corrupted the retail mask rom should still be bootable.

[UprightCarrot]

Best left to we professionals. Even if the flash were to become corrupted the retail mask rom should still be bootable.

Thats the funny part the one with corrupted flash now boots some disc's yet the one that worked died. I dont think I did that bad its like the 10th or so thing I've ever soldered but I can only put it down to bad workmanship or I'm missing something on the mod.
This is the first I did that boots some discs
http://i35.photobucket.com/albums/d1...l/DSCF0982.jpg
http://i35.photobucket.com/albums/d1...l/DSCF0985.jpg

[APE]

Doesn't look too bad of a soldering job but the thing is unless you check each pin it is very easy for it to look good but have a failure waiting to happen.

I should know, it has occurred a few different times. Now I just check the soldering after I'm doing to avoid anything unexpected.

[alex81]

Where's the switch?

[Bad_Ad84]

Dont need a switch if you do not want to change between bios's.

You can just disable the original and use the replacement. You could also just remove the original completely.

[DarthCloud]

Dont need a switch if you do not want to change between bios's.

You can just disable the original and use the replacement. You could also just remove the original completely.

If the chip is pre-programmed it's ok, but if not you need the switch at least until you program it with DreamShell.

[Bad_Ad84]

He bought it from me, it's pre programmed :)

[hellbelly]

I've got a DC with a VA0 motherboard now, and a bunch of pre-flashed chips from Bad_Ad84 :)

If I want to do a complete BIOS replacement, remove the old BIOS and put the flash chip in, am I right in thinking that the only funny business I have to worry about is the power going to legs 1 and 23? (get 3v from leg 1 of IC302).

Do I have to worry about legs 12 and 44 at all?

Thanks in advance :)
Pete

[hellbelly]

ignore my previous question. Leg 12 is already connected to the correct place anyway. Just had to wire up 44 as per the original diagrams :)

[-=FamilyGuy=-]

My eternal gratitude goes to the fine gentlemen, or lady for that matters, who tells me what is the error on my mod (click to enlarge):



Original bios woks quite well, but DreamShell can't write to the flash chip, it doesn't complain while deleting it though.

I know it's not the best solder job ever (big ass solder tip), but it should be ok imo... I'll rework every solder contact to see if it fixes it once I'll have the time...

Thanks in advance,

FG

[alex81]

check the quality of solder on pin 11

[DarthCloud]

I bet it's the write signal (pin 44) that as a cold solder joint. Try to put some flux on it and reheat.

Also are you sure the write signal in connect to the right pin of the 29LV002 should on pin 9. From the picture it look to be on the wrong via.

Sould be connect to the via that is right (on the picture) to the pin with the white dot.

[APE]

It'll erase the whole chip regardless of it being wired 100% correct or not.

[-=FamilyGuy=-]

So I guess it only says it erases, but actually doesn't?

@DarthCloud: It's on the right via, the line from pin 9 goes straight up then 45 degree counterclockwise to a via (on the 3rd picture I posted), I've soldered on that via. It could be a cold joint though.

@alex: I'll rework pin 11 for sure!

Thank you guys and let's hope it'll be working for me! I guess I could hardly have overheated the chip?

FG

[DarthCloud]

Probably not the case but it's always good to check that the flux is not acid base ;). Unlikely but better to checkout if everything else look ok.