Search found 610 matches
- Sat Mar 16, 2024 1:38 pm
- Forum: NESemdev
- Topic: ABS,X and (ZP),Y dummy read test ROM
- Replies: 19
- Views: 23886
Re: ABS,X and (ZP),Y dummy read test ROM
readme.txt says you need to check the source. set_test 3,"LDA abs,x" jsr begin ldx #$22 lda $2000,x ; no dummy read jpl test_failed lda $2002 jmi test_failed jsr begin ldx #$22 lda $20E0,x ; dummy read from $2002 jmi test_failed lda $2002 jmi test_failed jsr begin ldx #$22 lda $20E2,x ; du...
- Thu Mar 14, 2024 2:33 pm
- Forum: NESdev
- Topic: NTSC timing questions
- Replies: 7
- Views: 515
Re: NTSC timing questions
Yep, same. The diagonal pattern is because the console cuts the line off slightly early while the color clock remains unchanged - so the pixels of the next line show slightly shifted artifacts. The difference keeps adding up and effectively resets after a few lines. The missing dot every other fram...
- Wed Mar 13, 2024 1:53 pm
- Forum: NESdev
- Topic: NTSC timing questions
- Replies: 7
- Views: 515
Re: NTSC timing questions
"The NTSC master clock is 21.47727273 MHz and each PPU pixel lasts four of these clocks" so if we divide by 4 and multiply 52.6μs (visible) we have 282.4 active pixels That's the part of the scanline where a device may output visible pixels, though some may be covered by the TV's bezel. T...
- Sat Mar 09, 2024 7:27 pm
- Forum: SNESdev
- Topic: SNES cracktros?
- Replies: 5
- Views: 454
- Sat Mar 09, 2024 2:36 pm
- Forum: SNESdev
- Topic: SNES cracktros?
- Replies: 5
- Views: 454
- Tue Mar 05, 2024 11:25 pm
- Forum: General Stuff
- Topic: DMCA Anti-Circumvention Laws and Video Game Dumping
- Replies: 39
- Views: 2168
- Tue Mar 05, 2024 11:20 pm
- Forum: Newbie Help Center
- Topic: Finding sprite data
- Replies: 3
- Views: 266
Re: Finding sprite data
You need more than a hex editor for that. An emulator (or a savestate tool, e.g. vSNES ) with a memory viewer can show you where the graphics are in RAM (and ROM, if they're uncompressed). A built-in hex editor may then let you copy or save the data. (Note that vSNES only supports ZSNES and older SN...
- Wed Feb 28, 2024 4:41 am
- Forum: SNESdev
- Topic: snes assembly - beginnings, a few questions (wla-65816)
- Replies: 104
- Views: 8131
Re: snes assembly - beginnings, a few questions (wla-65816)
The SNES PPUs have some registers that can be written to during active display / HBLANK, e.g. the BG scrolling positions, though some may depend on the hardware revision. Most of the VRAM/OAM/CGRAM transfers should be done by using regular DMA during VBLANK/FBLANK with buffers in WRAM/SRAM. EDIT: wh...
- Sat Feb 24, 2024 11:33 am
- Forum: SNESdev
- Topic: Question about SNES object priority rotation feature
- Replies: 6
- Views: 334
Re: Question about SNES object priority rotation feature
just trying to confirm if, when using the sprite priority rotation method, flickering will only show visibly on-screen when the sprites go over the sprites/slivers per scan line limit - or if even any sprites just normally passing in front of each other would be constantly flickering even when ther...
- Sat Feb 24, 2024 11:19 am
- Forum: SNESdev
- Topic: snes assembly - beginnings, a few questions (wla-65816)
- Replies: 104
- Views: 8131
Re: snes assembly - beginnings, a few questions (wla-65816)
So it works like an advanced, "automated" NES mapper that sees all Banks at once and automatically switches everything "on the fly" using long jumps/addressing? The CPU has a 24-bit addressing space. Normal program execution only changes the lower 16 bits of the program counter,...
- Fri Feb 23, 2024 9:29 pm
- Forum: SNESdev
- Topic: Trying to make the backmost sprites drop out first.
- Replies: 42
- Views: 2508
- Thu Feb 22, 2024 3:19 pm
- Forum: SNESdev
- Topic: SPC700 is similar to Paula ?
- Replies: 7
- Views: 624
Re: SPC700 is similar to Paula ?
I've been struggling to find technical information on the SPC700. [...] I thought this chip performed some kind of sample-based synthesis, but from what I've read, it's just a PCM playback soundchip ? Retro Game Mechanics Explained https://youtu.be/n5eTOGZdnTU?list=PLHQ0utQyFw5KCcj1ljIhExH_lvGwfn6G...
- Mon Feb 12, 2024 12:39 am
- Forum: SNESdev
- Topic: What's the real cycle timing for LDA abs,x?
- Replies: 8
- Views: 727
Re: What's the real cycle timing for LDA abs,x?
datasheet page 24 note 3psycopathicteen wrote: ↑Sat Feb 10, 2024 9:24 pm I checked all the WDC manuals and they say nothing about an extra cycle being added when index registers are in 16-bit mode
- Fri Feb 02, 2024 5:36 pm
- Forum: SNESdev
- Topic: Max sprites on-screen using the following approach . . .
- Replies: 9
- Views: 899
- Fri Feb 02, 2024 2:11 am
- Forum: SNESdev
- Topic: Trying to make the backmost sprites drop out first.
- Replies: 42
- Views: 2508
Re: Trying to make the backmost sprites drop out first.
Couldn't you just use sprite priority rotation to randomize the sprite drops?