Search found 45 matches

by Haruka
Sat Jul 04, 2020 1:33 am
Forum: NESdev
Topic: Need help! How to debug on real hardware?
Replies: 11
Views: 3026

Re: Need help! How to debug on real hardware?

That's indeed a way of solution, although it is extremely tedious and low-efficiency. Anyway I'll try it until I find a better method. Flashing the cartridge again and again using kazzo is very time-consuming. Maybe I should borrow a powerpak or Everdrive N8 from my friends, which is far more faster...
by Haruka
Thu Jul 02, 2020 5:33 pm
Forum: NESdev
Topic: Need help! How to debug on real hardware?
Replies: 11
Views: 3026

Re: Need help! How to debug on real hardware?

I used two 512kb flash chips. But I connected both A18 to +5v to half their sizes. So they are 256k now. From what I've already learned, kazzo will automatically padding the ROM to fill up the whole chip if the PRG/CHR of the ROM is smaller than the chip size. And I also tested some smaller ROMs. (e...
by Haruka
Thu Jul 02, 2020 8:53 am
Forum: NESdev
Topic: Need help! How to debug on real hardware?
Replies: 11
Views: 3026

Re: Need help! How to debug on real hardware?

Well, it is not fpga-based. It is a legit famicom cartridge (Namco Classic) that removed both mask ROM chips and replaced with flash chips. And I programmed it using kazzo. EDIT: After written the ROM to the flashcart I then dumped it and compared the result with the ROM itself. Both identical on ev...
by Haruka
Thu Jul 02, 2020 7:47 am
Forum: NESdev
Topic: Need help! How to debug on real hardware?
Replies: 11
Views: 3026

Re: Need help! How to debug on real hardware?

Yes exactly. I tested on many emulators including mesen.
And I always enable this on every emulator that provides this option.
by Haruka
Thu Jul 02, 2020 1:05 am
Forum: NESdev
Topic: Need help! How to debug on real hardware?
Replies: 11
Views: 3026

Re: Need help! How to debug on real hardware?

Yes, I tested other mapper 19 games (both official and my other mapper hack ROMs) on my cartridge and every game works perfectly. Only this one does not work on it.
by Haruka
Wed Jul 01, 2020 11:09 pm
Forum: NESdev
Topic: Need help! How to debug on real hardware?
Replies: 11
Views: 3026

Need help! How to debug on real hardware?

Hello guys. I'm working on a mapper hack project recently, and the hacked ROM works perfectly on almost all modern emulators. But when running on a flash cartridge, the ROM locks up immediately after power-on. Solid color screen, no sound, no response on controller input, no response on hardware res...
by Haruka
Tue May 26, 2020 10:15 pm
Forum: NES Hardware and Flash Equipment
Topic: Recover PPU./WR when ppu writes to palette, possible?
Replies: 3
Views: 1557

Re: Recover PPU./WR when ppu writes to palette, possible?

Can we recover this signal from the operation of the CPU side? i.e. when PPU.A0~PPU.A13 == $3F00~$3FFF && PPU./CS == 0 && PPU.CPU A0~PPU.CPU A2 == $07 && PPU.CPU R/W == 0? I mean, sure, but what for? I mean, other than the NESRGB and HDNES kits, which rely on replacing the value that the CPU writes...
by Haruka
Tue May 26, 2020 8:48 pm
Forum: NES Hardware and Flash Equipment
Topic: Recover PPU./WR when ppu writes to palette, possible?
Replies: 3
Views: 1557

Recover PPU./WR when ppu writes to palette, possible?

I'm not quite clear of the sync between CPU and PPU, and signal timing on the PPU pins. Let's assume I'm currently writing to the palette through PPU registers $2006 and $2007: lda #$30 sta $2006 lda #$00 sta $2006 lda #$3F sta $2007 when the last code "sta $2007" is executed (or is executing? I'm n...
by Haruka
Fri Jul 26, 2019 12:25 am
Forum: NES Hardware and Flash Equipment
Topic: VRC-VI multicart
Replies: 39
Views: 27501

Re: VRC-VI multicart

This is what the 74LS32 is doing on that cart (might not be wired physically like this on my cart as I just drew this from my head). The circuit below is meant to make up to the fact that 62256s have no non-inverted Chip Enable pin. VRC6_32KWRAM.PNG The second OR gate is useless, isn't it? Connect ...
by Haruka
Thu Jul 25, 2019 11:55 pm
Forum: NES Hardware and Flash Equipment
Topic: VRC-VI multicart
Replies: 39
Views: 27501

Re: VRC-VI multicart

I bought some chips and made a test.
I used a 74'139 to decode WRAM access, completely bypassed WRAM /CE pin on VRC6. The result is still a failure. It proves that the VRC6 itself is not damaged. There must be somewhere other than VRC6 that caused the weird problem.
by Haruka
Sun Jul 21, 2019 2:14 pm
Forum: NES Hardware and Flash Equipment
Topic: VRC-VI multicart
Replies: 39
Views: 27501

Re: VRC-VI multicart

What you do with the /WE signal of the FRAM? connect straight to R/W? Connected like this, right? CE# = /WRAM_CE coming from mapper logic. OE# = GND? WE# = R/W? Well, yes. To make things clear, let me explain more. Actually I made a little adapter from the circuit I posted previously. 28.png As you...
by Haruka
Sun Jul 21, 2019 7:58 am
Forum: NES Hardware and Flash Equipment
Topic: VRC-VI multicart
Replies: 39
Views: 27501

Re: VRC-VI multicart

I also noticed the difference between SRAM and FRAM. So I searched the net and found the following circuit. 27.png This circuit has been tested on my namco163 flashcart and worked fine. But on VRC6, something weird happens. If the game(bootloader for the VRC6 multicart) never enables WRAM (i.e. $B00...
by Haruka
Sun Jul 21, 2019 5:58 am
Forum: NES Hardware and Flash Equipment
Topic: VRC-VI multicart
Replies: 39
Views: 27501

Re: VRC-VI multicart

Now I understand how to use 74'32. Why not power 74'32 with +5V, and pull 62256's /CE to +3V of battery through a big res(e.g. 100k)? This eliminates the power consumption of 74'32 when cart is not working.
by Haruka
Sat Jul 20, 2019 8:24 pm
Forum: NES Hardware and Flash Equipment
Topic: VRC-VI multicart
Replies: 39
Views: 27501

Re: VRC-VI multicart

No, that won't be a bus conflict. The VRC6 itself is only going to assert /PRGRAMCE or /PRGROMCE, never both. What if the 82p cap was short-circuit? That would explain why disabling FRAM does make the game booting fine while otherwise don't. I don't suppose you have access to an oscilloscope? Nope....
by Haruka
Sat Jul 20, 2019 2:45 pm
Forum: NES Hardware and Flash Equipment
Topic: VRC-VI multicart
Replies: 39
Views: 27501

Re: VRC-VI multicart

A design flaw in the NES/FC makes it impossible to tell whether the CPU is accessing $E000 or $6000 until it's too late, so memory access to $E000 will briefly look like access to $6000. By delaying the RAM's enable signal, that momentary incorrect pulse won't be received by the RAM, and writes to ...