nesdev.org

Yes, 100% match. Why does it work for you and not for me???

I've been mostly testing in nestopia (debian:1.45+dfsg-1) and fceux (debian:2.2.1+dfsg0-2), but I only rarely tested using wine or virtualbox with nintendulator (windows:0.975, but doesn't support CHRROM on UNROM), and fceux (windows:2.2.2)... which is why:
In the changelog for FCEUX 2.2.2 they claims they "fixed" mapper 2. And by "fixed" I mean the most hilarious piece of crap I've ever seen. Never fear, if you actually built a reproduction it would work fine: we only need to prevent bus conflicts on the bits that are used by the latch (two for a 64KiB UNROM game), not all eight.

Anyway, would a moderator please split this entire tangent about Portopia?

lidnariq wrote:I've been mostly testing in nestopia (debian:1.45+dfsg-1) and fceux (debian:2.2.1+dfsg0-2), but I only rarely tested using wine or virtualbox with nintendulator (windows:0.975, but doesn't support CHRROM on UNROM), and fceux (windows:2.2.2)... which is why:
In the changelog for FCEUX 2.2.2 they claims they "fixed" mapper 2. And by "fixed" I mean the most hilarious piece of crap I've ever seen. Never fear, if you actually built a reproduction it would work fine: we only need to prevent bus conflicts on the bits that are used by the latch (two for a 64KiB UNROM game), not all eight.

Anyway, would a moderator please split this entire tangent about Portopia?

Thanks a lot, you made my life 100x easier! Awesome! Working in Neutopia/Windows. And I agree on the thread split, sorry for the offtopic questions.

Hi,

I stumbled upon this thread trying to make this game. I've created the rom from your fix and burnt it and put it in an UNROM board but it doesn't work. I'm guessing this is due to the CHR-RAM? But all UNROM boards have this so is it okay to just take that chip out and put in the CHR data from the ROM? Or will rewiring be required?

Thanks,

- Hubz

What kind of "doesn't work" ? Even before you've replaced the CHRRAM with a CHRROM it should display a smear of colors (not unlike what you'll see running it in Nintendulator), just not the actual content.

The pinout of the 8KiB RAM used should be compatible with that of an 8 KiB 'PROM. If you're using an EEPROM, you might want to tie its /WRite input high, but flash or UVEPROMs shouldn't need any help.

Hmmm no smear of color just a solid screen. I"m using a 27c512 EEPROM but I have mirrored it up to 64kb for both PRG and CHR on a California Games PCB. I didn't think it would need rewiring since it is a 28 pin EEPROM but maybe I am wrong. I went ahead and took out the CHRRAM and added the CHR ROM but no difference unfortunately.

Thanks for any advice you can provide,

- Hubz

Do you get the klaxon from the opening animation when it first starts? If not, something is going wrong much earlier than the CHR should matter.

I dug around for a bit, and just discovered a "funny" bug where if, for some reason, the game boots with the movable bank bank as the final bank it'll crash... On the unlikely chance that's what's wrong, you could add a couple of resistor+LEDs to the outputs of the 74'161. Or just test it with a voltmeter. But ... that's pretty unlikely; the game itself never writes 3 to the register, and the latch really should power up with the value 0 in it.

Pinout of the 74'161. Check the pins labeled Q0 and Q1 (13 and 14); if both are high that's what's wrong. If so, it can be fixed by lifting the /CLEAR pin (1) on the 74'161 and adding a resistor and capacitor. If that is what's wrong, the Correct Fix involves finding some free space in the final 16kB of the game... which in turn involves either DvD having their notes on where there's any, or someone else sitting down and play testing giving me a complete CDL.

If that's not what's wrong, I don't have any better guesses than rewiring problems... You did rewire pin 22 to be ground instead of A16? Should have been the only thing you had to do.

No go unfortunately... I didn't have pin 22 to GND but do now and still nothing. Has anybody made a UNROM Portopia by chance?

Thanks,

- Hubz

I can't tell: did you test the 74'161's outputs?

Also, I failed to be specific, the rewiring I meant was on the PRG ROM, not CHR ROM.

How easily can you program another 'PROM to test with? If it's easy, try testing with Magic Floor or Galaxian or something else tiny and reasonably guaranteed to work.

Sorry haven't gotten to mess with this until now.

I'm a newbie with all this so not sure what you mean by the outputs being high? Do you have any link on explaining how to test that with a Multimeter?

Thanks!

- Hubz

Assuming you can get access to the cartridge while it's in the NES and on, measure the voltage on the pins I've circled in red. As long as both of them aren't more than 3V, then that's not what's wrong.

Just want to say thank you and I got this to work finally after messing with it again today. It was a combination of a bad EEPROM i believe as well as I had the wrong pin run to GND. I stupidly was counting for a 32 pin chip instead of 28 so I was off. Thanks for all your help now I can finally play this game on the console!