Author Topic: OS 2.11 mapper glitches on japanese titles?  (Read 603 times)

0 Members and 1 Guest are viewing this topic.

Offline Asriazh

  • Newbie
  • *
  • Posts: 4
  • Karma: +0/-0
    • View Profile
OS 2.11 mapper glitches on japanese titles?
« on: April 13, 2021, 03:52 PM »
Since yesterday, I got an Everdrive N8 Pro. It's using OS 2.11 right now. The thing I immediately noticed was, that quite a few japanese titles have graphical corruptions, while US titles seem to mostly work just fine. I got an EU PAL NES with 47k expansion audio mod.
Here are two examples.
Rom info:

 Glitch:


Second Rom info:

Glitch:


On the second game it's not as obvious, but the status bar is scrolling with the level.
I was checking the +5V line, but it seems to be stable at +4.78V I even removed the old Hitachi voltage regulator which had +4.68V, but that didn't make a difference. At least my PAL NES is running cooler now :p I also replaced the main filter capacitor with a Wuerth 105°C 2200µF one. Another thing I tried was to add a USB cable to the Everdrive N8 Pro for more stability, but that didn't make a difference either. So it's a mapper glitch? Something that's known? A fix, or a hint fpr how I can fix this myself would be nice. Thank You!

Offline Richardragon87

  • SNESAdvance Revival Coder
  • Hero Member
  • *****
  • Posts: 613
  • Karma: +11/-0
    • View Profile
Re: OS 2.11 mapper glitches on japanese titles?
« Reply #1 on: April 13, 2021, 09:09 PM »
Kind of reminds me of the same issues Pocketnes/Visualnes on the GBA emulator on the older versions did when displaying modes, likely it may replicate the same issue when you play various regions or change certain hz to 50 and 60 which resulted in that top screen looking garbled.., mainly it can be replicated when you change a region from NTSC to PAL where the top screen ends up looking like that so I don't think its a mapper issue as I have seen a real mapper problem that is way worse and more troublesome.
« Last Edit: April 13, 2021, 10:57 PM by Richardragon87 »
[quote Random dating spambotJ

Quote
Post changed:

Great, the photo didn't load! Does anyone know how to fix this?
In any case, my other photos can be viewed here, I will be glad to meet you, I love flirt))

P.S Richardragon87! Don't write me again, dude! You're in ignore list!

Offline Sarge

  • Sr. Member
  • ****
  • Posts: 355
  • Karma: +16/-0
    • View Profile
Re: OS 2.11 mapper glitches on japanese titles?
« Reply #2 on: April 14, 2021, 12:05 AM »
The first thing I'd suspect is using a PAL-region console. I'd try testing those ROMs in an accurate emulator and see if you see the same behavior at 50Hz with NTSC ROMs like that.
Hardcore Retro Gaming - Discuss games ten years old or older! Now with a modern gaming section!

http://hardcoreretrogaming.boards.net/

Offline Asriazh

  • Newbie
  • *
  • Posts: 4
  • Karma: +0/-0
    • View Profile
Re: OS 2.11 mapper glitches on japanese titles?
« Reply #3 on: April 14, 2021, 12:58 AM »
That's a great idea! I started Fceux and loaded "Akumajou Densetsu (J) [!].nes" in NTSC mode. No corruption. Then I switched to PAL mode and the exact same corruption I saw on my PAL NES were visible. So I guess it's a PAL/NTSC timing thing and there's nothing i can do about it apart from getting an NTSC NES/Famicom heh... and in case of the Famicom, a 72 to 60 adapter. But then the expansion audio on the "western" Everdrive wouldn't work right anymore, cause the Famicom Everdrive N8 has an on cartridge amp and mixer. I ordered a Famicom from Japan with 19 games anyway :p At least it's nice to know that the glitches aren't a hardware fault and that my NES' PPU and everdrive N8 Pro is ok.
Here's a screenshot of the same glitch on Fceux switched to PAL

It's 100% the same. Thanks guys!

Offline Richardragon87

  • SNESAdvance Revival Coder
  • Hero Member
  • *****
  • Posts: 613
  • Karma: +11/-0
    • View Profile
Re: OS 2.11 mapper glitches on japanese titles?
« Reply #4 on: April 14, 2021, 01:25 AM »
That's a great idea! I started Fceux and loaded "Akumajou Densetsu (J) [!].nes" in NTSC mode. No corruption. Then I switched to PAL mode and the exact same corruption I saw on my PAL NES were visible. So I guess it's a PAL/NTSC timing thing and there's nothing i can do about it apart from getting an NTSC NES/Famicom heh... and in case of the Famicom, a 72 to 60 adapter. But then the expansion audio on the "western" Everdrive wouldn't work right anymore, cause the Famicom Everdrive N8 has an on cartridge amp and mixer. I ordered a Famicom from Japan with 19 games anyway :p At least it's nice to know that the glitches aren't a hardware fault and that my NES' PPU and everdrive N8 Pro is ok.
Here's a screenshot of the same glitch on Fceux switched to PAL

It's 100% the same. Thanks guys!

One other thing that does jog my memory is it may be due to a HEX value needing to be changed, if I remember though it has been years since I had a go at making roms work for the NES that had broken mappers as I intend to do it for SNES on multi formats the rom called Wagyan Land had an issue where when the sprite moved across half of the screen would be clear but the other half would be garbled this also ended up happening in a game called Mappy Kids though unlike Wagyan Land it didn't result in the game causing gamplay to break apart such as the demo mode would cause stuff to incorrectly work as the CPU was only programmed to move in a certain way while the Mappy one had the same issue but didn't result in the gamplay being broken apart from the other side of the screen being garbled all the same it had the same scrolling issue, the solution was to change byte 6 from 40 to 41 using this...

https://www.onlinehexeditor.com/# (Used for fixing NES headers and also fixing NES roms changing byte 6 to one more number higher)

As for how it worked I think you had to enter the rom into the editor then select the number and type in the value then pressing a button created a save of the changed rom that you use on your device, it's kind of like editing values of other formats like SNES games to display something like a background or a foreground the value being in this case of byte 6 being changed from 40 to 41 will fix the issue where you see one half of the regular game and the other half is a unaligned mess then again I haven't corrected roms for years so take it with a pinch of salt and have a try.

Also when you change the byte remember to press enter when you type it in at the 0x40 area which is found in the 1st box on the far right when the byte 6 area saying 06 is selected and you click on the number that says it otherwise it wont correct it then just click the download and it should be made.
« Last Edit: April 14, 2021, 01:35 AM by Richardragon87 »
[quote Random dating spambotJ

Quote
Post changed:

Great, the photo didn't load! Does anyone know how to fix this?
In any case, my other photos can be viewed here, I will be glad to meet you, I love flirt))

P.S Richardragon87! Don't write me again, dude! You're in ignore list!

Offline Asriazh

  • Newbie
  • *
  • Posts: 4
  • Karma: +0/-0
    • View Profile
Re: OS 2.11 mapper glitches on japanese titles?
« Reply #5 on: April 14, 2021, 01:50 AM »
I always wondered if "overclocking" the frequency crystal for the CPU of the Pal NES would do anything benefitial, to make NTSC games run correctly. There's a trimming capacitor next to the xtal; maybe its range would be enough to get the PAL NES from 1.66MHz up to the NTSC versions 1.79MHz and if this would disrupt any timings in a way, that would make the PAL NES not run at all anymore, or even with more glitches than we see on NTSC games on PAL NESes. Two crystals at different frequencies, switchable, would be ideal. I think I saw a mod on youtube, where the moddern claimed he could overclock PAL NESes, but never showed details or explained anything.

Offline Richardragon87

  • SNESAdvance Revival Coder
  • Hero Member
  • *****
  • Posts: 613
  • Karma: +11/-0
    • View Profile
Re: OS 2.11 mapper glitches on japanese titles?
« Reply #6 on: April 14, 2021, 01:58 AM »
I always wondered if "overclocking" the frequency crystal for the CPU of the Pal NES would do anything benefitial, to make NTSC games run correctly. There's a trimming capacitor next to the xtal; maybe its range would be enough to get the PAL NES from 1.66MHz up to the NTSC versions 1.79MHz and if this would disrupt any timings in a way, that would make the PAL NES not run at all anymore, or even with more glitches than we see on NTSC games on PAL NESes. Two crystals at different frequencies, switchable, would be ideal. I think I saw a mod on youtube, where the moddern claimed he could overclock PAL NESes, but never showed details or explained anything.

Over clocking does tend to give of the same result I remember some features PocketNES had was it said Dendy (Over clocked) which when selected did the same thing it would result in the top layer being the timer and score board moving across to the left while you moved to the right while other overclocked modes mainly PAL gave off a similar effect but this would dramatically slow down the game which I remember too well when Kid Dracula which I think is called on the famicom as Akumajou Dracula Special to garble the lower screen making it do the same thing, I think the PALCOM versions of Castlevania III also have this issue so using overclock isn't good.

Though for the garbled issue of the screen having two different sides it seems like the roms HEX value needs to be changed, now that my memory is coming back their was also the rom called Lupin III that also had this issue that was corrected the same way.
[quote Random dating spambotJ

Quote
Post changed:

Great, the photo didn't load! Does anyone know how to fix this?
In any case, my other photos can be viewed here, I will be glad to meet you, I love flirt))

P.S Richardragon87! Don't write me again, dude! You're in ignore list!

Offline Sarge

  • Sr. Member
  • ****
  • Posts: 355
  • Karma: +16/-0
    • View Profile
Re: OS 2.11 mapper glitches on japanese titles?
« Reply #7 on: April 14, 2021, 06:30 AM »
Glad that ended up being it - I've definitely seen some odd behavior like that before, both with PAL on NTSC and NTSC on PAL.
Hardcore Retro Gaming - Discuss games ten years old or older! Now with a modern gaming section!

http://hardcoreretrogaming.boards.net/

Offline nuu

  • Hero Member
  • *****
  • Posts: 2019
  • Karma: +88/-2
    • View Profile
Re: OS 2.11 mapper glitches on japanese titles?
« Reply #8 on: April 14, 2021, 09:11 AM »
I always wondered if "overclocking" the frequency crystal for the CPU of the Pal NES would do anything benefitial, to make NTSC games run correctly.
I'm pretty sure you must also change the CPU and PPU (and the CIC) to the NTSC equivalent in addition to changing the xtal, and in that case it's easier to just get an NTSC system.

Offline Asriazh

  • Newbie
  • *
  • Posts: 4
  • Karma: +0/-0
    • View Profile
Re: OS 2.11 mapper glitches on japanese titles?
« Reply #9 on: April 14, 2021, 06:00 PM »
I always wondered if "overclocking" the frequency crystal for the CPU of the Pal NES would do anything benefitial, to make NTSC games run correctly.
I'm pretty sure you must also change the CPU and PPU (and the CIC) to the NTSC equivalent in addition to changing the xtal, and in that case it's easier to just get an NTSC system.

Actually I looked into this a bit more and you have to pretty much leave the PPU clocking alone and add a programmed clock generator for the CPU side of things, disconnecting it from the original frequency crystal. That one runs at 26.601712MHz for the PAL version. Here comes the tricky part. To get to the actual MHz frequency, both the PPU and CPU have dividers inside their chips. For the NTSC version of the NES the dividers are /12 for the CPU and /4 for the PPU. But for the PAL version, they are CPU /16 and /5 fpr the PPU. So to get the PAL CPU to the 1.79MHz of the NTSC CPU but with a /16 divider the PAL CPU has, you'd have to add a 28,64MHz crystal to only the CPU side of things, lifting the frequency in pin of the CPU and connecting the programmed crystal to it, with some capacitor filtering. It might even be worth doing all this, if you're into that stuff, and you're bored... and want to prove a point :D That programmable crystal would also need a +3,5V powersource and the NES only has +5V as the lowest voltage. It's not hard to drop that voltage, but it's another "hurdle". Buying an NTSC NES/famicom model is the easier way, but also less cool and fun :D Oh yeah, and you'd have to buy a programmable crystal programmer too...
The way the Dendy clone NES did it, was to use the standard PAL crystal, running at 26.601712MHz, but to have a CPU chip, that had an internal divider of /15 instead of the PAL /16 divider. So that's what the "dendy" mode in many NES emulators is.

Offline Richardragon87

  • SNESAdvance Revival Coder
  • Hero Member
  • *****
  • Posts: 613
  • Karma: +11/-0
    • View Profile
Re: OS 2.11 mapper glitches on japanese titles?
« Reply #10 on: April 15, 2021, 04:06 AM »
The way the Dendy clone NES did it, was to use the standard PAL crystal, running at 26.601712MHz, but to have a CPU chip, that had an internal divider of /15 instead of the PAL /16 divider. So that's what the "dendy" mode in many NES emulators is.

So I guess my theory was correct they replicated the problem in emulation where I could give the experience I had to you so you could rectify it, glad it helped you.
[quote Random dating spambotJ

Quote
Post changed:

Great, the photo didn't load! Does anyone know how to fix this?
In any case, my other photos can be viewed here, I will be glad to meet you, I love flirt))

P.S Richardragon87! Don't write me again, dude! You're in ignore list!

Offline nuu

  • Hero Member
  • *****
  • Posts: 2019
  • Karma: +88/-2
    • View Profile
Re: OS 2.11 mapper glitches on japanese titles?
« Reply #11 on: April 15, 2021, 10:59 AM »
Dendy isn't overclocking though, but emulation of PAL clones which is kind of a mix between NTSC Famicom/NES and PAL NES as Asriazh described. The main use is for people who grew up with a Dendy or other PAL clone and want the system to behave like one.

Offline Richardragon87

  • SNESAdvance Revival Coder
  • Hero Member
  • *****
  • Posts: 613
  • Karma: +11/-0
    • View Profile
Re: OS 2.11 mapper glitches on japanese titles?
« Reply #12 on: April 15, 2021, 08:17 PM »
Dendy isn't overclocking though, but emulation of PAL clones which is kind of a mix between NTSC Famicom/NES and PAL NES as Asriazh described. The main use is for people who grew up with a Dendy or other PAL clone and want the system to behave like one.

All the same though, the way half of the screen is showing a completely different thing is due to the values needing to be changed it works for some well known Famicom roms and likely would correct that issue too.
[quote Random dating spambotJ

Quote
Post changed:

Great, the photo didn't load! Does anyone know how to fix this?
In any case, my other photos can be viewed here, I will be glad to meet you, I love flirt))

P.S Richardragon87! Don't write me again, dude! You're in ignore list!

Offline nuu

  • Hero Member
  • *****
  • Posts: 2019
  • Karma: +88/-2
    • View Profile
Re: OS 2.11 mapper glitches on japanese titles?
« Reply #13 on: April 16, 2021, 11:05 AM »
It's due to the Dendy having different timings from what the game is programmed for, just like if running on a PAL NES. The game relies on the NTSC timings and doesn't work correctly on PAL or Dendy.