VRC4 reproduction problems
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VRC4 reproduction problems
Hello friends. Someone can help me. I want to make a Japanese one Teenage Mutant Ninja Turtles, as a donor I took the game Racer Mini Yonku: Japan Cup .And faced with the following problem.The game runs, but has graphic artifacts.You can help fix this.EPROM PIN 30 (CHR A17) I connected to the 28th leg of the mapper.EPROM PIN 2 (CHR A16) to 22 Mapper Leg.CE (PIN22 EPROM) on the 10th leg of the mapper.OE (PIN 24 EPROM) connected to the ground.The other pins match.I can't figure out what I'm doing wrong.I use eprom W27C020
Re: VRC6 CHR Bank Malformed?
This is the 3rd thread in which you've posted this message, and this one is definitely the wrong place to ask.mir2sila wrote: ↑Tue May 18, 2021 9:28 am Hello friends. Someone can help me. I want to make a Japanese one Teenage Mutant Ninja Turtles, as a donor I took the game Racer Mini Yonku: Japan Cup .And faced with the following problem.The game runs, but has graphic artifacts.You can help fix this.EPROM PIN 30 (CHR A17) I connected to the 28th leg of the mapper.EPROM PIN 2 (CHR A16) to 22 Mapper Leg.CE (PIN22 EPROM) on the 10th leg of the mapper.OE (PIN 24 EPROM) connected to the ground.The other pins match.I can't figure out what I'm doing wrong.I use eprom W27C020
I would advise you to create a new topic in the NES Hardware -> Reproductions forum.
Quietust, QMT Productions
P.S. If you don't get this note, let me know and I'll write you another.
P.S. If you don't get this note, let me know and I'll write you another.
Re: VRC6 CHR Bank Malformed?
I'm here quite recently, and I don't know how to create a theme on my own.So I hope that someone will accidentally see my message and help me.Quietust wrote: ↑Tue May 18, 2021 9:32 amThis is the 3rd thread in which you've posted this message, and this one is definitely the wrong place to ask.mir2sila wrote: ↑Tue May 18, 2021 9:28 am Hello friends. Someone can help me. I want to make a Japanese one Teenage Mutant Ninja Turtles, as a donor I took the game Racer Mini Yonku: Japan Cup .And faced with the following problem.The game runs, but has graphic artifacts.You can help fix this.EPROM PIN 30 (CHR A17) I connected to the 28th leg of the mapper.EPROM PIN 2 (CHR A16) to 22 Mapper Leg.CE (PIN22 EPROM) on the 10th leg of the mapper.OE (PIN 24 EPROM) connected to the ground.The other pins match.I can't figure out what I'm doing wrong.I use eprom W27C020
I would advise you to create a new topic in the NES Hardware -> Reproductions forum.
Re: VRC4 reproduction problems
I have split this to a new thread, and deleted the duplicates.
Konami's PCBs should not have required any rework, to the best of my memory.
Konami's PCBs should not have required any rework, to the best of my memory.
Re: VRC4 reproduction problems
Thanks.There are boards from KONAMI where you need to redirect addresses.In most cases, these are boards where there are 28 holes,instead of the necessary 32.I've done games on a VRC chip before, and they worked.And this time it didn't work out.Here is a photo of my reproduction.[/img]
Re: VRC4 reproduction problems
Oh, specifically the 28-pin 128KB mask ROMs. Sure. Other than those, there should be no other rework.
You shouldn't have needed to connect CHR A17 or PRG A17, because both your PROMs are only 128KB in size.
There's nothing obviously wrong with your wiring. You moved A16 as needed on both ROMs, and presumably fixed both /OE and /CE on both chips (although I can't see from your photos).
... i wonder if you need to tie Vpp (pin 1) to +5V? The datasheet for the W27C010 isn't clear.
Re: VRC4 reproduction problems
these are both w27c020 chips (256 KB), the Chinese incorrectly entered the marking.My programmer confirmed this, that these are exactly 256 kb chips.lidnariq wrote: ↑Tue May 18, 2021 3:38 pmOh, specifically the 28-pin 128KB mask ROMs. Sure. Other than those, there should be no other rework.
You shouldn't have needed to connect CHR A17 or PRG A17, because both your PROMs are only 128KB in size.
There's nothing obviously wrong with your wiring. You moved A16 as needed on both ROMs, and presumably fixed both /OE and /CE on both chips (although I can't see from your photos).
... i wonder if you need to tie Vpp (pin 1) to +5V? The datasheet for the W27C010 isn't clear.
The OE signal goes to the OE VRC4, and the SE signal goes to the ground.VPP in the air.
Re: VRC4 reproduction problems
That's correct for PRG, but what did you do for CHR?
The W27C010 datasheet isn't clear about whether that is OK. (It only says 5V, 12V, or 14V are permitted). You could try tying it to +5V and see if it changes anything.VPP in the air.
Re: VRC4 reproduction problems
For CHR, everything is the same as for PRG
I connected the VPP to 5 volts, nothing has changed
Re: VRC4 reproduction problems
CHR CE and OE are connected to ground and VRC4 pin 10?
Re: VRC4 reproduction problems
Unfortunately, that uses up all the ideas I have as to why you're having problems.
Re: VRC4 reproduction problems
Re: VRC4 reproduction problems
Just check all address lines of chr, probably someone is teared off.