Help burning NAOMI BIOS ROMs

[twistedsymphony]

So I've got 3 NAOMI1 boards and 1 NAOMI2 board and I need new BIOS chips for all but 1 of them as I bought a Rev H bios from Summit back when I got my first NAOMI.

I decided it was time to buy an EPROM burner as I also have an MK2 PCB that needs new ROMs burned.

I bought a brand new GQ-4X from MCU Mall as well as the ADP-054 adapter and a UV eraser.

Here's where I'm at.
The adapter board is aligned at the bottom of the Ziff socket, the chip is aligned at the bottom of the adapter socket with the notch at the top. Jumper 1 is set to 1-2 which should be correct for this chip. I'm using an external power supply for the burner to ensure the voltages are good. and verifying voltages in the hardware test menu says it passes perfectly.

I have 1 spare M27C160 BIOS chip that wasn't being used, it worked but it was a rev A so it was mostly useless. I got the drivers installed and the programming software installed. I was able to read and verify the data on the chip, I put it in the eraser and was able to use the programmer to verify that it was fully erased. But when I go to write I get a write failed message pretty much immediately:

Write failed, Address=0x000004, Buffer=0x39 Device=0x38

Reading back from the chip after the failure shows that the first few bytes were written and that's it...

FFE3 2843 39FF FFFF FFFF FFFF FFFF FFFF...

it should be:
FFE3 2843 3964 1843 0944 0944 3950 0A24...

Then I have to erase the chip again before I try again.

I've heard that the V3/V4 jumper should be changed if there are problems but it doesn't seem to make a difference.

I don't think I'm doing anything wrong. I'm doing exactly what the instructions and every guide I've read says to do. but if anyone has any advice it'd be appreciated.

 

[kuze]

have you tried different chips/brands? Some programmers are picky about certain brands, though it's also possible the chip is just bad. Also, try writing at a slower speed if possible.

 

[TylerDurden67]

when I got problem, it came from my uv eraser.
It seems OK but i have to erase a several times x40minutes.
But I own an wellon, maybe it's just an configuration of your programmer.

 

[twistedsymphony]

have you tried different chips/brands? Some programmers are picky about certain brands, though it's also possible the chip is just bad. Also, try writing at a slower speed if possible.

As I stated, I only have the 1 chip and it's an original Sega issued chip that I'm trying to reprogram (STMicroelectronics) it was working before I erased it. I've tried writing at the slowest allowable speed setting and it didn't make any difference.

when I got problem, it came from my uv eraser.
It seems OK but i have to erase a several times x40minutes.
But I own an wellon, maybe it's just an configuration of your programmer.

I've been letting my chip erase for about an hour between attempts. I am verifying that the erase was successful before I make a burn attempt but it doesn't seem to make a difference.

Trying to figure out if it's a configuration problem is the whole reason I started this thread. I described everything that I'm doing and how I have everything setup,I've found 4 different guide and they all say to do the same thing, which is the same thing that I'm doing. So If there is a configuration issue I don't really know what I should be trying differently.

 

[TylerDurden67]

when I erase a chip, doing it for 40 minutes, my programmer display that it's an blank chip fully erased too.
Starting flashing it and soon after error too.
So it's not fully erased.

Do it like this, on uv eraser,for an hour.
Then redo it, after moving your chip in a different place and position
And to be sure, do it again.
If after that you can flash it, the uv.eraser don't do correctly it's job

It's a kind of this?

 

[Mitsurugi-w]

I can vouch that the bios chips will just go bad. They may operate fine but not read fine in a programmer or program.

We just dumped an undumped Naomi Debug Bios. It operated correctly in the motherboard. I could not dump it though because it was so worn. We had to send it off to someone who could dump it one byte at a time.

How many different chips have you tried? I've never used that particular burner before.

 

[twistedsymphony]

when I erase a chip, doing it for 40 minutes, my programmer display that it's an blank chip fully erased too.
Starting flashing it and soon after error too.
So it's not fully erased.

Do it like this, on uv eraser,for an hour.
Then redo it, after moving your chip in a different place and position
And to be sure, do it again.
If after that you can flash it, the uv.eraser don't do correctly it's job

It's a kind of this?

yeah that almost exactly how my eraser looks. I'll try what you suggested moving it to another position and erasing several times before burning. Thanks.

I can vouch that the bios chips will just go bad. They may operate fine but not read fine in a programmer or program.

We just dumped an undumped Naomi Debug Bios. It operated correctly in the motherboard. I could not dump it though because it was so worn. We had to send it off to someone who could dump it one byte at a time.

How many different chips have you tried? I've never used that particular burner before.

I only have the 1 chip right now. I think I have another spare chip somewhere but I haven't been able to find it yet. I just yesterday ordered some newer revisions of the same chip so I can try those later this week and see if it makes a difference.

 

[twistedsymphony]

Ok so I tried two other chips and they both fail to write at the exact same spot at the first one. this leads me to believe that it's something to do with my burner or my setup and not the chips themselves.

 

[kuze]

Ok so I tried two other chips and they both fail to write at the exact same spot at the first one. this leads me to believe that it's something to do with my burner or my setup and not the chips themselves.

Well if you get a different burner, I'd recommend the top3000.

 

[twistedsymphony]

Ok so I tried two other chips and they both fail to write at the exact same spot at the first one. this leads me to believe that it's something to do with my burner or my setup and not the chips themselves.

Well if you get a different burner, I'd recommend the top3000.

damn, I wish I knew about that one before I ordered the GQ-4X, looks like a much nicer setup. I'm assuming that's what you use? what can you tell me about it?

 

[kuze]

Ok so I tried two other chips and they both fail to write at the exact same spot at the first one. this leads me to believe that it's something to do with my burner or my setup and not the chips themselves.

Well if you get a different burner, I'd recommend the top3000.

damn, I wish I knew about that one before I ordered the GQ-4X, looks like a much nicer setup. I'm assuming that's what you use? what can you tell me about it?

yeah the top3000 is what I use, I got it because it doesn't need a 16 bit adapter and it also supports pal/gal chips. It's a pretty solid device and the PC software is regularly updated. The only issue I've encountered is that it can be picky with some more uncommon brand eproms, like Sony. I've never had any problems with ST or TI chips though. It works fine for writing Naomi bios chips BTW.

 

[twistedsymphony]

So I got the new chips in that I ordered, they're still STs but a newer revision and brand new, un-burned. I also got in the new power adapter that I ordered (I was previously borrowing one from another device).

I decided to try another burn and it burned perfectly first time... I'm not sure if it was the new chips, or the new power supply... I'm planning on erasing the older chips again and trying again to see if maybe just the new power supply makes a difference, failing that I'm going to try rigging the eraser to disable the timer and let it run overnight to see if maybe they just need a long erase period in order to take a burn.

worse case I toss them and just burn new chips.

--------

For those of you who've burned NAOMI bios. I ripped the data from a working rev H chip that I already had, but I wanted to try the region switching bios

looking at the hex of that bios it doesn't look the same as the rev H data that I ripped (though it should look nearly identical) are those .ic27 files encrypted or encoded in some format other than a .bin?

 

[XianXi]

Are you using a 16 bit adapter? Keep in mind that a 27C160 supports both 8 bit and 16 bit modes but you will need a 16 bit adapter to program it for 16 bit.

 

[twistedsymphony]

Are you using a 16 bit adapter? Keep in mind that a 27C160 supports both 8 bit and 16 bit modes but you will need a 16 bit adapter to program it for 16 bit.

yes I'm using the ADP-054 16-bit adapter that I mentioned in the first post.

 

[XianXi]

Are you using a 16 bit adapter? Keep in mind that a 27C160 supports both 8 bit and 16 bit modes but you will need a 16 bit adapter to program it for 16 bit.

yes I'm using the ADP-054 16-bit adapter that I mentioned in the first post.

Ah, I was wondering what that was. I'd try with a new chip. That one sounds like it's bad or the legs are dirty/not making good contact. I usually shift the chip/adapter once I lock the ziff a few mm left or right to ensure a good connection.

 

[twistedsymphony]

Are you using a 16 bit adapter? Keep in mind that a 27C160 supports both 8 bit and 16 bit modes but you will need a 16 bit adapter to program it for 16 bit.

yes I'm using the ADP-054 16-bit adapter that I mentioned in the first post.

Ah, I was wondering what that was. I'd try with a new chip. That one sounds like it's bad or the legs are dirty/not making good contact. I usually shift the chip/adapter once I lock the ziff a few mm left or right to ensure a good connection.

I do shift the chip to ensure good contact per the instructions included with the programmer. I was having this issue with 3 different chips, all different revisions all different ages, all previously working before erasing and all failing to write on the exact same bit. Per my post above I managed to properly program a brand new chip.

I'm content to just use new chips but my only real question right now is the one I posted above about .ic27 files.

 

[yavuzg]

For those of you who've burned NAOMI bios. I ripped the data from a working rev H chip that I already had, but I wanted to try the region switching bios

looking at the hex of that bios it doesn't look the same as the rev H data that I ripped (though it should look nearly identical) are those .ic27 files encrypted or encoded in some format other than a .bin?

I used the p1pkin's (from arcadeotaku) multi region BIOSes for Naomi1 and 2 without problem. I'm not sure if they are encrypted/encoded but as far as I remember, the multi-region BIOS for Naomi1 is based on Rev H BIOS and only 1 byte is supposed to be different than the original.

So your dump might not be correct. Did you try to verify your dump against the very same EPROM you ripped again?

 

[twistedsymphony]

For those of you who've burned NAOMI bios. I ripped the data from a working rev H chip that I already had, but I wanted to try the region switching bios

looking at the hex of that bios it doesn't look the same as the rev H data that I ripped (though it should look nearly identical) are those .ic27 files encrypted or encoded in some format other than a .bin?

I used the p1pkin's (from arcadeotaku) multi region BIOSes for Naomi1 and 2 without problem. I'm not sure if they are encrypted/encoded but as far as I remember, the multi-region BIOS for Naomi1 is based on Rev H BIOS and only 1 byte is supposed to be different than the original.
So your dump might not be correct. Did you try to verify your dump against the very same EPROM you ripped again?

The Dump I have from the original Rev H bios was verified as correct, and it boots and runs fine on the newly burned chip. It has the Sega copyright and bios version information in the header, the .ic27 files from p1pkin do not, it's all just gibberish. This is why I was asking if it needed to be converted or decryped; as you said it should only have 1 byte difference but I don't see any similarities between them at all other than I dumped the Rev H as a raw bin file and p1pkin's file is a .ic27

 

[rtw]

Rev H as a raw bin file and p1pkin's file is a .ic27

p1pkin's dump is a raw binary, it only needs to be burned. ic27 is the location on the motherboard.

 

[twistedsymphony]

Rev H as a raw bin file and p1pkin's file is a .ic27

p1pkin's dump is a raw binary, it only needs to be burned. ic27 is the location on the motherboard.

that's what I had thought but it struck me as strange that it looked so different from the Sega Rev H chip that I had. maybe it got corrupted during the download or the unzipping. I suppose it couldn't hurt to grab it again.