Writing CHR to UNROM Board With Kazzo INL/Retro Programmer.

I recently got my UNROM Flash Board, and am able to program it as long as I only write PRG when I write CHR it says verify OK but I load the programed cart in my Console and there is no CHR, and I think but am not sure, my UNROM board is suppose to have at least 8kb CHR.

I can erase PRG but when I try to Erase CHR I get an error, and i have programed my UNROM Board with games that don't have CHR and they work fine.

The reason I wanted to make use of CHR on UNROM is because I had this crazy idea to put Super Mario Bros on UNROM, my resulting GAME works in Emulators having 128kb PRG and 8kb CHR on Mapper 2. But when I load it on to the UNROM board all I get is the PRG all though I wrote both PRG and CHR to the Board, and when I load the game I can tell it loaded the PRG and not the CHR becasue it's SMB and it will play with out CHR although Garbled.

I did write the PRG First and the CHR second, after having erased it but it doesn't erase CHR I just get an Error when I try it, but it does say Verify OK when I write it but the CHR Doesn't take.. Do the UNROM boards even allow the use of CHR. I don't Know I'm totally new to this.

Also I read some where that the INL UNROM NOT self-flashable Boards were made to allow 32kb CHR. But I don't if that is true either.

http://www.infiniteneslives.com/nessupplies.php#UxROM

UNROM has CHR-RAM, you can't flash it. The software has to fill it up while the NES is running.

UNROM can't have 32k CHR either because it has no CHR banking. 8k is all that is possible.

As rainwarrior pointed out, erasing/flashing Chr on a board with CHR-RAM doesn’t make sense. Sounds like you were looking for a CNROM board instead, or perhaps NROM? I’m very confused what your goal is though. Feel free to submit a support ticket if you’d like to work out a return/swap.

That makes Sense and is what it meant by Not Self-Flashable, I still hadn't warped my head around the differences of CHR-RAM vs. CHR-ROM.

Is okay I had gotten a CNROM Flash board too I just had this newbie idea to run SMB as UNROM it worked in my Emulator. At least I did figure out how to flash my boards.

Thanks for the help. I just was trying to do something that wasn't correct, I think I'll stick to more normal Flashing from now on.. All The Best..

Self flashable is for homebrew use meaning the cartridge can reprogram it's PRG-ROM flash while playing in the NES. It's a modern alternative to battery backed save ram.

Are you sure about this? What did you do to make that work? Did you write your own loader program to copy CHR data from PRG-ROM to CHR-RAM at boot time? How did you get around the fixed bank of UNROM to create such a loader for a NROM game on a UNROM mapper?

Yes 'normal' flashing means you need an external programmer like the kazzo to erase and flash the PRG-ROM and CHR-ROM when present. UNROM doesn't have CHR-ROM, it has CHR-RAM instead. RAM looses it's data when power is removed (ie no battery backing), so you can't 'flash' RAM. It must be loaded by the program at boot or run time.

If he did, it was probably the same way I mapper-hacked Solar Wars from CNROM to UNROM: copy the CHR ROM from bank 0, then park the switchable bank in bank 2 during runtime.

But I suspect he didn't, and he's using emulators' interpretation of mapper 2 + CHR ROM as a fixed 8K bank of CHR ROM, much as Morita Shogi (NesCartDB) has an 8K CHR ROM on SNROM.

Yeah, there's very little reason for emulators to reject mapper 2 + 8k CHR-ROM, even though Nintendo never made such a thing.

...but the board in question has RAM on it.

Yep, that is what I did as tepples suspected I just enlarged the PRG of SMB to 128kb and then added the 8kb CHR-Rom to it into an NES File
and put it on UNROM as my rom was 136kb. Emulators seem to allow it and I wasn't making the connection that my board had CHR-RAM instead.

Also I got confused by this article, https://wiki.nesdev.com/w/index.php/UNROM_512 down near the bottom where it read's "InfiniteNesLives four-screen mirroring variation" but that isn't the UNROM 128KB STANDARD Board I have and I still had overlooked the fact that I was dealing with CHR-RAM and not CHR-ROM, some one had explained to me the difference long ago.

I've not yet figured out how to load CHR-RAM into my PRG-ROM.

I do have a unrelated question. On SNES boards it says they can be reprogrammed ~100,000 times.
How many times can you reprogram the NES Flash Boards?



I wondered what Self flashable is for.. So the normal UNROM boards don't have save ram.. I think most UNROM games either have a Password system or no saving of data at all. Thanks for the Info..

The NOR flash used in our NES boards has same ~100,000 erase/write cycle endurance. It's far more than you will be able to humanly achieve.

Awesome that is great, I figured it was likely Infinite.

Is there anyway to get the Holy Diver Batman program or something similar back on my flash board after I've erased it?

Never mind I found it http://www.pineight.com/nes/ and extracted the PRG from the UNROM version.

Thank you.