Search found 610 matches

by creaothceann
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...
by creaothceann
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...
by creaothceann
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...
by creaothceann
Sat Mar 09, 2024 2:36 pm
Forum: SNESdev
Topic: SNES cracktros?
Replies: 5
Views: 454

Re: SNES cracktros?

Some are listed here, possibly with videos:

https://www.pouet.net/prodlist.php?orde ... com&page=1
by creaothceann
Tue Mar 05, 2024 11:25 pm
Forum: General Stuff
Topic: DMCA Anti-Circumvention Laws and Video Game Dumping
Replies: 39
Views: 2168

Re: DMCA Anti-Circumvention Laws and Video Game Dumping

segaloco wrote: Tue Mar 05, 2024 8:10 pm they even took the source code down... that doesn't need to disappear because of this [...] the code sans-keys is none of their business....
They can demand whatever they want in the settlement conditions.
by creaothceann
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...
by creaothceann
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...
by creaothceann
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...
by creaothceann
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,...
by creaothceann
Fri Feb 23, 2024 9:29 pm
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.

SNES AYE wrote: Fri Feb 23, 2024 12:26 pm I don’t fully understand what OAM is doing to be honest
OAM is just 2 pieces of memory (128 * 32 bits = 512 bytes and 128 * 2 bits = 32 bytes) that are accessed in a somewhat peculiar way.
All the sprite rendering quirks are because of the PPU chips.
by creaothceann
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...
by creaothceann
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?

psycopathicteen 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
datasheet page 24 note 3
by creaothceann
Fri Feb 02, 2024 5:36 pm
Forum: SNESdev
Topic: Max sprites on-screen using the following approach . . .
Replies: 9
Views: 899

Re: Max sprites on-screen using the following approach . . .

dougeff wrote: Fri Feb 02, 2024 6:06 am Perhaps a mid screen FORCE BLANK could do it
SMK is doing that
by creaothceann
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?