Search found 10 matches

by N·K
Thu Jun 10, 2021 4:00 pm
Forum: NESdev
Topic: Problem with palette discoloration when PPU is turned off during rendering.
Replies: 15
Views: 1133

Re: Problem with palette discoloration when PPU is turned off during rendering.

My AV Famicom serial number was HN10804140. I checked again the type of stickers and the arrangement of parts visible from the back, and I still think it's the HVCN-CPU-02. However, the conditions for this phenomenon to occur seem to be quite unstable. The probability of the phenomenon occurring on ...
by N·K
Wed Jun 09, 2021 9:00 pm
Forum: NESdev
Topic: Problem with palette discoloration when PPU is turned off during rendering.
Replies: 15
Views: 1133

Re: Problem with palette discoloration when PPU is turned off during rendering.

I'd be interested to know what PPU revision is in N·K's AV Famicom - maybe this glitch does not affect the RP2C02G present in most front loading NES units? I don't have a screwdriver for the special screws used in AV Famicom, so I can't disassemble it ... However, as far as I can tell from the foll...
by N·K
Wed Jun 09, 2021 2:56 am
Forum: NESdev
Topic: Problem with palette discoloration when PPU is turned off during rendering.
Replies: 15
Views: 1133

Re: Problem with palette discoloration when PPU is turned off during rendering.

Thanks for the reply! This issue was also reported by Vectrex28 on the NESDev Discord about a week ago, though he didn't have a good test ROM yet, so thank you for posting one. It does sound like it's a previously-unknown, unemulated PPU glitch, though the mechanism is definitely not obvious. I've n...
by N·K
Tue Jun 08, 2021 1:47 am
Forum: NESdev
Topic: Problem with palette discoloration when PPU is turned off during rendering.
Replies: 15
Views: 1133

Re: Problem with palette discoloration when PPU is turned off during rendering.

I did some additional testing, and to my surprise, simply scrolling the BG and stopping the PPU at the visible scan line caused the discoloration.... (This happened even if the name table was $2000 or $2400.) I updated the test ROM. But to be honest, I'm beginning to think that the palette discolora...
by N·K
Sun Jun 06, 2021 8:59 am
Forum: NESdev
Topic: Problem with palette discoloration when PPU is turned off during rendering.
Replies: 15
Views: 1133

Problem with palette discoloration when PPU is turned off during rendering.

Hello! The other day, when I was testing a game I was working on with my AV Famicom (HVC-101), I encountered a strange phenomenon. Specifically, when I was scrolling with the nametable at $2800 or $2C00, if I turned PPU off, changed the XY scroll, and then turned PPU on again, the BG palette changed...
by N·K
Sat Dec 05, 2020 2:14 am
Forum: Newbie Help Center
Topic: The problem when writing 0 to $C000 in the real MMC3
Replies: 12
Views: 5571

Re: The problem when writing 0 to $C000 in the real MMC3

That's what I get for skipping over the quote assuming it was just a previous post. :) That's very interesting behavior. The OR with #$80 seems to match what's shown in the picture, but it looks like it was able to do 4 scanlines each time before encountering the problem, and it sounds like it only...
by N·K
Fri Dec 04, 2020 7:40 pm
Forum: Newbie Help Center
Topic: The problem when writing 0 to $C000 in the real MMC3
Replies: 12
Views: 5571

Re: The problem when writing 0 to $C000 in the real MMC3

Resolved! It seems to be caused by trying to write to $c001 in succession on every scan line. Taken from mmc3_test readme.txt If $C001 is written, the counter clocked, then $C001 written again, on the next counter clock the counter will be ORed with $80 (revision B)/frozen (revision A) and neither d...
by N·K
Thu Dec 03, 2020 3:25 am
Forum: Newbie Help Center
Topic: The problem when writing 0 to $C000 in the real MMC3
Replies: 12
Views: 5571

Re: The problem when writing 0 to $C000 in the real MMC3

Thanks for the reply! There are two revisions of the MMC3: Old revision = Write #$00 to $C000, IRQ is only once. New revision = Write #$00 to $C000, IRQ is every scanline. It sounds like the real MMC3B chip you're using is an "old revision" chip. Here's the wiki page on it , it also says how to iden...
by N·K
Mon Nov 30, 2020 8:40 pm
Forum: Newbie Help Center
Topic: The problem when writing 0 to $C000 in the real MMC3
Replies: 12
Views: 5571

The problem when writing 0 to $C000 in the real MMC3

Hello. I recently produced a test ROM to learn the IRQ interrupt for MMC3. In this ROM, I tried to make it possible to change the value to be written to $C000 from 0-255 with the up and down buttons, and to swap BG and sprite pattern table addresses with the B button. It worked as expected when runn...
by N·K
Tue May 12, 2020 6:40 am
Forum: Homebrew Projects
Topic: AAAEEEOOO 8-bit version!
Replies: 6
Views: 8878

AAAEEEOOO 8-bit version!

I recreated the popular YouTube video "AAAEEEOOO" on the NES and Famicom!

Original video : https://youtu.be/v1K4EAXe2oo

I don't understand English, so I'm using machine translation.
I'm sorry if it's a weird sentence.