What symptoms do you see?
Are you sure Mr. Gimmick can start without the IRQ?
Search found 10426 matches
- Sun Apr 11, 2021 11:18 pm
- Forum: NES Hardware and Flash Equipment
- Topic: Sunsoft FME-7 VHDL
- Replies: 5
- Views: 135
- Sun Apr 11, 2021 8:27 pm
- Forum: NES Hardware and Flash Equipment
- Topic: Sunsoft FME-7 VHDL
- Replies: 5
- Views: 135
- Sun Apr 11, 2021 7:57 pm
- Forum: NES Hardware and Flash Equipment
- Topic: Sunsoft FME-7 VHDL
- Replies: 5
- Views: 135
Re: Sunsoft FME-7 VHDL
wait until (falling_edge(romsel)); [...] when 0 to 7 => ppu_bank(reg_sel) <= unsigned(cpu_data_i); Data bus is not valid on the falling edge of /ROMSEL! You must wait for the rising edge, or approximately 70ns after the falling edge. See: https://forums.nesdev.com/viewtopic.php?p=244126#p244126
- Sun Apr 11, 2021 11:19 am
- Forum: SNESdev
- Topic: About audio in rom bandwidth capabilities, and a external cpu...
- Replies: 12
- Views: 416
Re: About audio in rom bandwidth capabilities, and a external cpu...
During access to addresses $21xx, the B bus is a copy of the bottom 8 bits of the A bus. During DMA it's driven according to the DMA registers. The rest of the time, it does random weird things. I don't think it's ever undriven (although looking at the die shot would let us tell), but it seems to ge...
- Sat Apr 10, 2021 11:57 pm
- Forum: NESdev
- Topic: NES PAL version, wavy edges on graphics
- Replies: 14
- Views: 916
Re: NES PAL version, wavy edges on graphics
Unfortunately, I promise, it's a problem with just how the NES generates video. Certain TVs might deal better with edges between different brightnesses of grey, but vertical lines between colors will always have that appearance. NTSC NESes have a different artifact - the pattern happens every 3 scan...
- Sat Apr 10, 2021 9:11 pm
- Forum: Other Retro Dev
- Topic: Was the GBA's sound worse than the 8-bit NES's sound?
- Replies: 7
- Views: 381
Re: Was the GBA's sound worse than the 8-bit NES's sound?
The 8-bit depth is pretty relevant here. I don't think it's fair to say that it means "almost nothing"? While I was definitely being flip, my point was more that focusing on a single bit of difference in bit depth is why it's misleading. The GBA has the problem that its output DAC always resamples ...
- Sat Apr 10, 2021 1:45 pm
- Forum: Other Retro Dev
- Topic: Was the GBA's sound worse than the 8-bit NES's sound?
- Replies: 7
- Views: 381
Re: Was the GBA's sound worse than the 8-bit NES's sound?
So why is the NES with 7-bit samples and a 1.79 MHz CPU sound better than the GBA with a MUCH better CPU, and 8-bit samples, and if the GBA could sound better, is there a example without the "scratchy" sound of the GBA? Because bit depth means almost nothing. https://en.wikipedia.org/wiki/1-bit_DAC
- Fri Apr 09, 2021 5:02 pm
- Forum: NESemdev
- Topic: RockNES 5.66 -April 9th 2021-
- Replies: 16
- Views: 6690
Re: RockNES 5.66 -April 9th 2021-
2. You mean like use its mapper emulation to intercept $4016/$4017 access kind of like a Game Genie? Or patch the ROM on the fly? The Everdrive does have mapper 99 listed so maybe it does something hacky with these games. I have no idea if mapper 99 was listed years ago when I tried VS SMB though. ...
- Fri Apr 09, 2021 4:01 pm
- Forum: NESemdev
- Topic: RockNES 5.66 -April 9th 2021-
- Replies: 16
- Views: 6690
Re: RockNES 5.66 -April 9th 2021-
um... 1- Vs. SMB was only released for the 2C04-0004, so if you played it on a home console on a flashcart, the colors would all be Very Wrong. If you don't remember them being Very Wrong, you most likely played a version that was patched for home consoles. very-wrong-colors.png 2- The Everdrive can...
- Fri Apr 09, 2021 2:21 pm
- Forum: NESemdev
- Topic: RockNES 5.66 -April 9th 2021-
- Replies: 16
- Views: 6690
Re: RockNES 5.66 -April 9th 2021-
The Vs. System is not the same hardware as the NES, and you shouldn't have $4016 and $4017 behaves the same for both.
It is absolutely correct that if you put Vs. SMB on a NES cart it would perceive the coin drop as continuously activated.
It is absolutely correct that if you put Vs. SMB on a NES cart it would perceive the coin drop as continuously activated.
- Thu Apr 08, 2021 8:32 pm
- Forum: GBDev
- Topic: GBDK2020 - Is it smart trying to outsmart the compiler ?
- Replies: 8
- Views: 433
Re: GBDK2020 - Is it smart trying to outsmart the compiler ?
If you don't know that the compiler is doing the slow thing, then it's definitely premature to try to "help" it.
This is true for all optimizations ever, honestly. If you don't know what's taking up time, your assumption will probably be wrong and will make things worse instead.
This is true for all optimizations ever, honestly. If you don't know what's taking up time, your assumption will probably be wrong and will make things worse instead.
- Thu Apr 08, 2021 8:15 pm
- Forum: GBDev
- Topic: GBDK2020 - Is it smart trying to outsmart the compiler ?
- Replies: 8
- Views: 433
Re: GBDK2020 - Is it smart trying to outsmart the compiler ?
Do you know that SDCC is doing the slower thing?
- Thu Apr 08, 2021 5:00 pm
- Forum: SNESdev
- Topic: SNES oscilloscope readings?
- Replies: 30
- Views: 1188
Re: SNES oscilloscope readings?
You could get one of the very cheap 8/16-channel ones. Search AliExpress for "fx2lp". You'll need all the probes, too, so it may not work out to a win to buy things piecemeal, though.
It's limited - only 12MSa/sec at 16 channel, but it's what I used for the PPU logic analyzer traces.
It's limited - only 12MSa/sec at 16 channel, but it's what I used for the PPU logic analyzer traces.
- Thu Apr 08, 2021 1:36 pm
- Forum: Newbie Help Center
- Topic: 4-screen VRAM and mappers
- Replies: 3
- Views: 293
Re: 4-screen VRAM and mappers
There are rather few mappers that explicitly can provide 4 nametables: NES-commerical era: mapper 4/206 = MMC3 or its simpler predecessor Namco 108 mapper 77 Games released for the "Vs System" arcade cabinets (and not at home) Modern homebrew era: mapper 30 = UNROM512 (INL 4sc variant) mapper 111 = ...
- Thu Apr 08, 2021 2:18 am
- Forum: SNESdev
- Topic: SNES oscilloscope readings?
- Replies: 30
- Views: 1188
Re: SNES oscilloscope readings?
Is the S-CPU well enough understood Probably? a new-production chip Unaffordable. You can't get custom silicon without an initial outlay on the order of $80k+ in a pin-compatible package I've seen clever things with castellated PCBs and mezzanine connectors, such as the UltraPIF or fancy flex PCBs,...