Sim City on Nestopia/Other emulators

Discuss emulation of the Nintendo Entertainment System and Famicom.

Moderator: Moderators

User avatar
*Spitfire_NES*
Posts: 306
Joined: Fri May 21, 2010 4:10 pm

Sim City on Nestopia/Other emulators

Post by *Spitfire_NES* »

Hi all,

Not sure if many of you know, or maybe I'm late but on Xmas day 2018 the rom for SimCity nes was released for all to enjoy! :beer: :mrgreen:

However, seems like a quite a few emulators seem to be having an issue with the maps being scrambled once generated, FCEultra and others also have this issue with it.

Can someone help me get it working? The rest of the game seems fine, but once you generate a map, the graphics become scrambled up and it virtually renders the game unplayable. Is this a problem with the game or something off with the rom itself? I tried running the game and the info shows it as:

File: simcity.nes
CRC: FDC7C50B
SHA-1: 5E8F67BEFB2B1BCBD0384E3144ACB2766FC3E443
System: NES-NTSC
Board: EKROM, Mapper 5
PRG-ROM: 128k
CHR-ROM: 128k
W-RAM: 8k
Solder Pad: H:1 V:0
Battery: Yes
File: simcity.sav
Dump: Unknown

On a side note you can also tell something is wrong because the generate new map screen shows tiles instead of the actual map. It is supposed to show the map.
User avatar
zeroone
Posts: 939
Joined: Mon Dec 29, 2014 1:46 pm
Location: New York, NY
Contact:

Re: Sim City on Nestopia/Other emulators

Post by zeroone »

A few people ran into this issue, myself included. See this thread for 2 solutions discussed.
User avatar
*Spitfire_NES*
Posts: 306
Joined: Fri May 21, 2010 4:10 pm

Re: Sim City on Nestopia/Other emulators

Post by *Spitfire_NES* »

zeroone wrote:A few people ran into this issue, myself included. See this thread for 2 solutions discussed.
Thanks for the reply Zeroone! 8-) From what I am reading, I am only seeing one solution which is to remove read protection from PRG RAM, correct? What is the other?

Looks like Nintaco and Nestopia most likely share the same solution with this. And yea, I thought I used the search function before posting this thread. Weird that I missed it.
User avatar
zeroone
Posts: 939
Joined: Mon Dec 29, 2014 1:46 pm
Location: New York, NY
Contact:

Re: Sim City on Nestopia/Other emulators

Post by zeroone »

*Spitfire_NES* wrote:
zeroone wrote:A few people ran into this issue, myself included. See this thread for 2 solutions discussed.
Thanks for the reply Zeroone! 8-) From what I am reading, I am only seeing one solution which is to remove read protection from PRG RAM, correct? What is the other?

Looks like Nintaco and Nestopia most likely share the same solution with this. And yea, I thought I used the search function before posting this thread. Weird that I missed it.
viewtopic.php?f=2&p=231548#p231422
User avatar
*Spitfire_NES*
Posts: 306
Joined: Fri May 21, 2010 4:10 pm

Re: Sim City on Nestopia/Other emulators

Post by *Spitfire_NES* »

Thanks Zeroone! Did you also need to external attribute mode (palette and the address override) when not in frame in Nintaco?

Looks like I need to get some more rest. :? I'm 2 for 2 today when it comes to missing things. :lol:
User avatar
zeroone
Posts: 939
Joined: Mon Dec 29, 2014 1:46 pm
Location: New York, NY
Contact:

Re: Sim City on Nestopia/Other emulators

Post by zeroone »

*Spitfire_NES* wrote:Thanks Zeroone! Did you also need to external attribute mode (palette and the address override) when not in frame in Nintaco?
No.

Neither of things might be your specific issue. But studying those regions of your mapper might give you some insight into your problem.
User avatar
koitsu
Posts: 4201
Joined: Sun Sep 19, 2004 9:28 pm
Location: A world gone mad

Re: Sim City on Nestopia/Other emulators

Post by koitsu »

I'm not sure how this is being overlooked or unmentioned, but, folks here do know that this is a prototype dump, achieved very late last year, correct?

What this means is that emulators that use a quirks database (most/many do) -- Nestopia / Nestopia UIE is one such emulator -- may lack the necessary quirks to ensure it plays correctly.

I think that fact need be brought up/mentioned. If it works on real hardware, then yes, this is an emulation quirk/problem that needs to be fixed, but omitting the fact it's a prototype feels (a little bit to me) like it's misleading.
User avatar
*Spitfire_NES*
Posts: 306
Joined: Fri May 21, 2010 4:10 pm

Re: Sim City on Nestopia/Other emulators

Post by *Spitfire_NES* »

Hey koitsu, thanks for the reply. Yes, I am talking about the proto dump from December. I didn't mean to make it sound like I was omitting that information. Through and through this is a prototype.

It def works on real hardware though as observed in videos and playthroughs I have watched. Not just for nestopia, but other emulators are also having the same issue. Not all are though.

This is def a problem that needs to be fixed on emulators. IIRC, hard drivin proto also when released also gave quite a few emulators trouble at first.

I'm not sure a database tweak would fix this for nestopia, though one hopes it is trivial for this as some fixes have been in the past.
User avatar
koitsu
Posts: 4201
Joined: Sun Sep 19, 2004 9:28 pm
Location: A world gone mad

Re: Sim City on Nestopia/Other emulators

Post by koitsu »

Ah yes, I see now! Thank you! The linked post from zeroone didn't make sense to me at first. I'm like "PRG-RAM write protection? Who cares? What relevancy does this have?", but then I scrolled up in the referenced thread and realised it's extremely relevant.

To explain: I'm always suspicious of prototype or "development ROMs" etc.. They're often coveted by people who spent stupid sums of money to get them, usually can't guarantee a proper dump of the ROM (so corruption there is possible), and often won't help with ensuring such a cart make it into the hands of someone who can do the proper RE so that it can be dumped + emulated properly... yet they release what they have into the wild and people say "it doesn't work right!" when for all they know it doesn't work right on real hardware either (because coveting collectors/hoarders refuse to assist in the process). It's even more complicated when the game uses a still-not-quite-fully-understood mapper like MMC5. (Ys 3 on NES was another example, back in the late 90s during the emulation peak, and I was part of that. It's a cart I own that was weird/interesting in some of the PPU stuff it did. I suspected for a long time it was a PCB with a unique set of PPU address line traces, but that got refuted, I think.)

Anyway, yeah, it sounds like this is going to require emulator code changes. Can you submit a GitHub Issues request for NestopiaUE discussing this problem + what needs to be done? If not, I can try to do the submission, but may need zeroone's help. I might have to spend time in Mesen and getting familiar with MMC5 (the latter I try to avoid as much as possible, haha).

We also need to have a clear/concise bullet list of what emulators (and their versions, as well as platform (ex. Linux vs. OS X vs. Windows -- yes this matters!)) experience the problem so that reports can be submit to each appropriate author/team. As it stands now, it sounds like some version of FCEUltra (is that FCEUX? Or are you using the older FCEUXSP? Etc. etc. -- too many forks!) doesn't work, some version of Nestopia doesn't work, and some version of Nintaco doesn't work. "And others" is not particularly helpful if we want to have this emulation problem fixed.

A good example would look like this (AND THIS IS ONLY AN EXAMPLE):

* NestopiaUE v1.49, Win32 -- corrupted graphics during {whatever}
* FCEUX 2.2.3, Win32 -- bulldozing causes my PC to catch fire and stabs my dog
* FCEUX SVN xxxxxxxx, Win32 -- works
* Mesen DevWin 0.9.7.92, Win64 -- works
* NintendulatorDX v35, Win32 -- corrupted graphics during {whatever}
* Nemulator 4.2, Win32 -- works

etc... you get the idea.
User avatar
*Spitfire_NES*
Posts: 306
Joined: Fri May 21, 2010 4:10 pm

Re: Sim City on Nestopia/Other emulators

Post by *Spitfire_NES* »

Yea no worries friend. :beer: The initial start of this thread was to hopefully fix the issue on nestopia, but it seems like there are other emulators that have/had this problem.

Nintaco had this same problem - Zeroone fixed it
FCEUMM core in retroarch - works
Nestopia (martin 1.40 version)- does not work/scrambled maps
Nestopia undead - does not work/scrambled maps
NES FCEUltra Ver: rev22 - does not work/scrambled maps
MISTER - had this same issue - was fixed
FCEUX 2.2.3 - works like a charm!


Yea, i do not mind opening a ticket request for undead in the future. I know that this is not the place to constantly open threads about nestopia fixes, but since this problem plagues other emulators, i figured i would start here. Its been pretty quiet as of recent over at undead as well.

It seems a tad over my head, but i've always had fun with these things within the community here. And usually a fix is always not too bad.

Zeroones (nintaco) problem and nestopias problem seem to be the exact same and most relevant. Everything else is OK its just the map that is scrambled.

IN regards to what Zeroone had to do, i perused some of the code in nestopia's MMC5 implementation and all i could find was this:

Code: Select all

NES_POKE_D(Mmc5,5102)
			{
				if (data == Regs::WRK_WRITABLE_A)
					banks.security |= Regs::WRK_WRITABLE_A;
				else
					banks.security &= ~uint(Regs::WRK_WRITABLE_A);
			}

			NES_POKE_D(Mmc5,5103)
			{
				if (data == Regs::WRK_WRITABLE_B)
					banks.security |= Regs::WRK_WRITABLE_B;
				else
					banks.security &= ~uint(Regs::WRK_WRITABLE_B);
			}
zxbdragon
Posts: 498
Joined: Mon Dec 12, 2011 8:15 pm

Re: Sim City on Nestopia/Other emulators

Post by zxbdragon »

Follow wiki rewrite Nestopia MMC5 Code.
User avatar
*Spitfire_NES*
Posts: 306
Joined: Fri May 21, 2010 4:10 pm

Re: Sim City on Nestopia/Other emulators

Post by *Spitfire_NES* »

Thanks for the input Dragon!

While I do agree nestopia does need a re-write somewhat of MMC5. (castlevania III ahem ahem) I think in this instance one of the simple tweaks posted by zeroone above would work in this case. :D

Nintaco and Nestopia both have/had the same issue. The maps were the only part scrambled.
User avatar
rainwarrior
Posts: 8732
Joined: Sun Jan 22, 2012 12:03 pm
Location: Canada
Contact:

Re: Sim City on Nestopia/Other emulators

Post by rainwarrior »

koitsu wrote:To explain: I'm always suspicious of prototype or "development ROMs" etc.. They're often coveted by people who spent stupid sums of money to get them, usually can't guarantee a proper dump of the ROM (so corruption there is possible), and often won't help with ensuring such a cart make it into the hands of someone who can do the proper RE so that it can be dumped + emulated properly... yet they release what they have into the wild and people say "it doesn't work right!" when for all they know it doesn't work right on real hardware either (because coveting collectors/hoarders refuse to assist in the process). It's even more complicated when the game uses a still-not-quite-fully-understood mapper like MMC5. (Ys 3 on NES was another example, back in the late 90s during the emulation peak, and I was part of that. It's a cart I own that was weird/interesting in some of the PPU stuff it did. I suspected for a long time it was a PCB with a unique set of PPU address line traces, but that got refuted, I think.)
Does any of that apply to SimCity? Given who was involved I'm 100% sure they know how to dump a cartridge properly, and there was a ton of research done on the ROM before it was released. The release package had PCB photos, a written guide, an annotated disassembly by Cah4e3, compiled promotional artwork, a soundtrack rip... Was there ever a prototype dump release more ideal than this??
User avatar
koitsu
Posts: 4201
Joined: Sun Sep 19, 2004 9:28 pm
Location: A world gone mad

Re: Sim City on Nestopia/Other emulators

Post by koitsu »

Fair enough -- this game seems to be the exception to the rule; was just explaining my default suspicion.
User avatar
Sumez
Posts: 919
Joined: Thu Sep 15, 2016 6:29 am
Location: Denmark (PAL)

Re: Sim City on Nestopia/Other emulators

Post by Sumez »

Yeah, Frank Cifaldi was very involved in this. He's one of the people who's actually doing serious work towards preservation of video game history. If only all the people lamenting Nintendo taking legal actions against pirate sites would recognize what preservation actually is. </rant>
Post Reply