Search found 11205 matches

by lidnariq
Mon Mar 20, 2023 7:48 pm
Forum: SNESdev
Topic: SNES PPU Warmup Period?
Replies: 7
Views: 262

Re: SNES PPU Warmup Period?

Pretty certain there's no external bus activity from the 5A22 separate from the 65816 after reset - it would have shown up on some of poot36's logic analyzer traces.
by lidnariq
Mon Mar 20, 2023 11:01 am
Forum: Other Retro Dev
Topic: Blarrg NTSC filter with VICE emulator
Replies: 3
Views: 133

Re: Blarrg NTSC filter with VICE emulator

Blargg's filters - he only wrote ones for the NES, SNES, and SMS - are all based around the same core of taking three pixels (or 6 for when the SNES emits 512px) and generating 7 out. This is because 3 NES/SMS pixels are 2 colorburst cycles, and so things line up into a small operation that can be d...
by lidnariq
Sat Mar 18, 2023 11:32 am
Forum: NESemdev
Topic: VRC4 in VHDL
Replies: 1
Views: 101

Re: VRC4 in VHDL

what does "mirror(0)" do? It should just be 0...
by lidnariq
Fri Mar 17, 2023 2:14 pm
Forum: NES Hardware and Flash Equipment
Topic: SNES MARIO CHIP chip-on-board used for reproduction
Replies: 3
Views: 241

SNES MARIO CHIP chip-on-board used for reproduction

In the Discord, KML discovered that one of the SNES MARIO CHIP boards has all the signals needed brought out to test pads at the top of the board.

I asked if I had permission to repost this information so here it is:
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by lidnariq
Tue Mar 14, 2023 10:55 am
Forum: SNESdev
Topic: Is there an easy way to find out if the SNES has booted a game?
Replies: 4
Views: 365

Re: Is there an easy way to find out if the SNES has booted a game?

On the SNES, there's no other relevant question. The PPU output will be active (although black) if it's not in reset.
by lidnariq
Mon Mar 13, 2023 8:47 pm
Forum: Newbie Help Center
Topic: Bringing a new HI-DEF NES kit to market; where to start
Replies: 14
Views: 566

Re: Bringing a new HI-DEF NES kit to market; where to start

Unfortunately it appears Kevtris is no longer making the kits for game-tech to sell. Unfortunately, selling these things is a tech support nightmare. The most recent revision (4) of the analog equivalent (NESRGB) has been full of problems. HDMI is extra bonus mean, too. Analog standards have to put...
by lidnariq
Mon Mar 13, 2023 8:11 pm
Forum: NESemdev
Topic: Project NYDES - announcing a new FPGA emulator
Replies: 15
Views: 588

Re: Project NYDES - announcing a new FPGA emulator

and 720 vertical pixels is a nice multiple of the NES' 240 line output. It's worth pointing out that real NTSC SDTV CRTs don't display all 240 scanlines - some gets lost off the top and bottom - and many games rely on being able to conceal glitches there. Of course, that doesn't help in the face of...
by lidnariq
Mon Mar 13, 2023 5:36 pm
Forum: NESdev
Topic: NES advantage spinner mod, arcade1up spinner
Replies: 1
Views: 149

Re: NES advantage spinner mod, arcade1up spinner

I love you trying to play Contra with a spinner!

It'd be nice to see a little technical writeup.
by lidnariq
Mon Mar 13, 2023 5:33 pm
Forum: SNESdev
Topic: Is there an easy way to find out if the SNES has booted a game?
Replies: 4
Views: 365

Re: Is there an easy way to find out if the SNES has booted a game?

You could check the SNES mainboard's CIC's RESET output...
by lidnariq
Sun Mar 12, 2023 2:18 pm
Forum: NESdev
Topic: DPCM + $2007 reads
Replies: 22
Views: 842

Re: DPCM + $2007 reads

reading each byte in a loop until you get two identical reads in a row and then moving to the next byte? To do that, you couldn't rely on the PPU's internal address increment, you'd have to reset the address yourself each time you read $2007. But if you absolutely had to get the data from VRAM with...
by lidnariq
Sun Mar 12, 2023 11:27 am
Forum: NES Hardware and Flash Equipment
Topic: Kazzo USB rom dumper / dev cart programmer
Replies: 743
Views: 472106

Re: Kazzo USB rom dumper / dev cart programmer

Try this: board <- { mappernum = 225, cpu_rom = { size_base = 0x100000, size_max = 0x100000, banksize = 0x8000 }, ppu_rom = { size_base = 0x80000, size_max = 0x80000, banksize = 0x2000 }, cpu_romsize = 0x100000, cpu_banksize = 0x8000, ppu_romsize = 0x80000, ppu_banksize = 0x2000, ppu_ramfind = false...
by lidnariq
Sun Mar 12, 2023 11:12 am
Forum: NESdev
Topic: DPCM + $2007 reads
Replies: 22
Views: 842

Re: DPCM + $2007 reads

DPCM glitches cause byte deletions, not incorrect bytes, so it's not going to be a matter of going back and fixing the single errors - it's going to be a matter of restarting where you detected the error.
by lidnariq
Fri Mar 10, 2023 7:09 pm
Forum: NES Hardware and Flash Equipment
Topic: Kazzo USB rom dumper / dev cart programmer
Replies: 743
Views: 472106

Re: Kazzo USB rom dumper / dev cart programmer

Kazzo doesn't use drivers - it just talks to the USB device as a normal program. Original cartridges are not programmable at all - they had their contents physically put in when they were forged. Some small runs of games used "UV EPROM"s. Those can be erased and programmed, but not by the ...
by lidnariq
Thu Mar 09, 2023 9:04 pm
Forum: NES Hardware and Flash Equipment
Topic: Scanline counters on BNROM
Replies: 7
Views: 372

Re: Scanline counters on BNROM

Mapper 189 might exclusively refer to Namco 108 clones and not MMC3 clones, I'm not certain.
by lidnariq
Thu Mar 09, 2023 7:39 pm
Forum: NES Hardware and Flash Equipment
Topic: Scanline counters on BNROM
Replies: 7
Views: 372

Re: Scanline counters on BNROM

Someone made a board for ... I think na_th_an ... that is GNROM plus a scanline counter. If I remember, it's MMC3 minus the registers at 8000/8001, and those two have been replaced with direct PRG and CHR banks. But for versatility, I'd either use MMC5 (three NT fetches in a row mark a new scanline)...