Search found 4683 matches

by Dwedit
Sat Oct 01, 2022 11:13 am
Forum: NESemdev
Topic: Converting CHR RAM to RGBA textures
Replies: 4
Views: 875

Re: Converting CHR RAM to RGBA textures

I'm just going by my past experience with DirectDraw and Direct3D on a 2006 era laptop with Radeon x300 graphics. The bottleneck was CPU -> GPU transfers. What mattered was how much data was transferred. Once the data was in video memory, drawing it elsewhere was much faster. (Meanwhile going the ot...
by Dwedit
Fri Sep 30, 2022 3:55 pm
Forum: NESemdev
Topic: Converting CHR RAM to RGBA textures
Replies: 4
Views: 875

Re: Converting CHR RAM to RGBA textures

Partial texture updates are not slow (edit: At least when using the original native APIs), where did you hear that?
by Dwedit
Mon Sep 26, 2022 1:04 pm
Forum: SNESdev
Topic: stretching the Super FX
Replies: 33
Views: 2749

Re: stretching the Super FX

The SNES DOOM programmer said that by doing a horizontal stretch operation on the SNES rather than on the Super FX chip, you can basically double the Framerate of Doom. Too bad he didn't know that in 1994.

So that would be "stretching" the Super FX.
by Dwedit
Sun Sep 25, 2022 5:41 pm
Forum: NESdev
Topic: Help understanding code that changes individual background tiles during gameplay
Replies: 3
Views: 601

Re: Help understanding code that changes individual background tiles during gameplay

The topmost bit of a VRAM address is ignored, A20C is a mirror of 220C.
by Dwedit
Sat Sep 24, 2022 8:31 pm
Forum: NESdev
Topic: Help understanding code that changes individual background tiles during gameplay
Replies: 3
Views: 601

Re: Help understanding code that changes individual background tiles during gameplay

You have an address inside of video RAM (2000-2FFF) Write it out in Binary. You get something like this: 0010NNYYYYYXXXXX Lowest 5 bits are a X coordinate (in tiles). The next 5 bits are a Y coordinate in tiles. The next 2 bits pick which nametable it goes to (0, 1, 2, 3). For vertical mirroring (ho...
by Dwedit
Wed Sep 21, 2022 10:17 pm
Forum: NESdev
Topic: SMB1 Hacking
Replies: 19
Views: 1957

Re: Super Mario Bros. (NES) -- 1-Up Mushroom Sound Fix

Just change the code? You have everything in front of you there. Right before the "lda #Sfx_PowerUpGrab" line, you add another "lda PowerUpType", then move "cmp #$03", "beq SetFor1Up" immediately after that. Some of the comments in "Shroom_Flower_PUp"...
by Dwedit
Wed Sep 21, 2022 2:54 pm
Forum: NESdev
Topic: Does 30 fps look too uncanny for a retro style game?
Replies: 14
Views: 857

Re: Does 30 fps look too uncanny for a retro style game?

Wizards and Warriors 3 cheated, running the game at 30FPS but interpolating the player's coordinates and the camera at 60FPS.
by Dwedit
Tue Sep 20, 2022 9:10 pm
Forum: NESdev
Topic: SMB1 -- 5-3, 7-3 Change to Winter Graphics?
Replies: 7
Views: 683

Re: SMB1 -- 5-3, 7-3 Change to Winter Graphics?

Haven't looked at the source recently, but it might be possible to make another entry that points to all the old stuff, just with different properties?
by Dwedit
Sun Sep 18, 2022 12:20 pm
Forum: Reproduction
Topic: Issue with repro of "The Legend of Zelda Redux"
Replies: 8
Views: 597

Re: Issur with repro of "The Legend of Zelda Redux"

You shouldn't be seeing any files with sizes of 180K. Start over with clean ROM files (This hack wants PRG0), and apply the patch to that.
by Dwedit
Sun Sep 18, 2022 10:06 am
Forum: SNESdev
Topic: Hud
Replies: 7
Views: 613

Re: Hud

It depends on your requirements. Many games just used a portion of Layer 3 for the HUD, and overlayed a few sprites on top. This gives you a non-opaque HUD, but has very few colors, and the HUD area can conflict with a possible other use for layer 3. One example is Castlevania IV, where Layer 3 is u...
by Dwedit
Sat Sep 10, 2022 11:24 pm
Forum: NESdev
Topic: Between mmc1 and mmc3, which one is more convenient for manufacturing an actual cartridge?
Replies: 11
Views: 939

Re: Between mmc1 and mmc3, which one is more convenient for manufacturing an actual cartridge?

Just giving the PPU 16K of RAM provides this: 8K of CHR-RAM 4K of Nametable Memory (four screens) 3.75K of PPU scratch memory, only readable or writable during vblank or forced blanking time (does this actually work?) 256 bytes of inaccessible memory because it overlaps the palette Giving the PPU 32...
by Dwedit
Sat Sep 10, 2022 8:31 pm
Forum: NESdev
Topic: Between mmc1 and mmc3, which one is more convenient for manufacturing an actual cartridge?
Replies: 11
Views: 939

Re: Between mmc1 and mmc3, which one is more convenient for manufacturing an actual cartridge?

Simplest mappers are CNROM (mapper 3), BNROM (mapper 34), GNROM (mapper 66), AxROM (mapper 7). They only need the latch chip and nothing else. (Besides the CIC. You still need that.) UxROM (mapper 2) also needs a NAND chip to make the fixed bank happen. Note that higher mapper number does not indica...
by Dwedit
Sat Sep 03, 2022 2:22 pm
Forum: General Stuff
Topic: Why a lot of 8-bit (or alike) developers think we loved excessive difficulty?
Replies: 48
Views: 12808

Re: Why a lot of 8-bit (or alike) developers think we loved excessive difficulty?

On Android, you can add Qwerty as a keyboard, it's under language selection. You get all the punctuation, but then keys are a lot thinner and harder to accurately press.
by Dwedit
Sat Sep 03, 2022 8:51 am
Forum: NESdev
Topic: 65816 Exclusive Opcodes and How to Duplicate Them in 6502
Replies: 11
Views: 1289

Re: 65816 Exclusive Opcodes and How to Duplicate Them in 6502

The term here is "Unsigned Saturated Arithmetic". Want a lives counter that doesn't go up past 255, and doesn't go down below 0, and doesn't have any negative number nonsense.

Any time the value is changed, it must have unsigned overflow/underflow checking.
by Dwedit
Sat Sep 03, 2022 8:47 am
Forum: General Stuff
Topic: What would you change about the NES?
Replies: 54
Views: 4540

Re: What would you change about the NES?

That's a neat thought, but it would complicate the fetching sequence a bit, as you'd need attribute information to determine which pixel strip you are fetching from video memory, then conditionally reverse the bits in the fetched byte. But with one extra bit for palette selection on each of sprites ...