Search found 567 matches
- Sun Jan 08, 2023 9:05 pm
- Forum: GBDev
- Topic: GameBoy Program Counter behaviour
- Replies: 4
- Views: 1555
Re: GameBoy Program Counter behaviour
Open bus is whatever appeared on the data bus last; thus it is the last value the CPU have read/written. Indeed, if the last CPU fetch is the low byte of an memory address, then yes, that would be the open bus value, but if the instruction at 7FFF is a two or three byte instruction, then its remaini...
- Sun Jan 08, 2023 12:27 pm
- Forum: phpBB Issues
- Topic: Weird smiley in some thread title
- Replies: 11
- Views: 2276
Re: Weird smiley in some thread title
You made it disappear, didn't you? I can't see it anymore.
- Wed Jan 04, 2023 2:03 pm
- Forum: phpBB Issues
- Topic: Weird smiley in some thread title
- Replies: 11
- Views: 2276
Weird smiley in some thread title
Does anyone know what can cause that stray smiley? Does anyone see it when looking at that thread? On Chrome (108.0.5359.128) using Android 10. Screenshot_20230104_155133_com.android.chrome.jpg I can see it too when using Firefox (108.1.0 (Build #2015920443), 49ccb63dd+) It seems that the smiley is ...
- Fri Sep 30, 2022 7:59 pm
- Forum: Web Issues
- Topic: HTTPS is broken
- Replies: 30
- Views: 47063
Re: HTTPS is broken
Thank you for your quick response!
- Tue Sep 20, 2022 7:09 pm
- Forum: General Stuff
- Topic: Why a lot of 8-bit (or alike) developers think we loved excessive difficulty?
- Replies: 49
- Views: 15424
Re: Why a lot of 8-bit (or alike) developers think we loved excessive difficulty?
Call me a n00b, but I could only beat Megaman (1) on the PowerPak with save states. I also completed the 1st "run" of Recca with save states, there is simply no way I can beat this game normally, especially with the last boss which is insanely hard.
- Tue Sep 06, 2022 11:32 am
- Forum: SNESdev
- Topic: Was the SPC700's noise channel based on the 2a03's noise channel?
- Replies: 25
- Views: 3206
Re: Was the SPC700's noise channel based on the 2a03's noise channel?
And I interpreted it as "it sounds bland in that game", sounding like a NES game. This was said in contrast to Super Mario World which used the LFSR noise cleverly to make good looking sounds. I wasn't aware of that, that's really neat.
- Sat Jul 16, 2022 10:12 am
- Forum: Newbie Help Center
- Topic: 8x16 and whatever else unreg wants to know
- Replies: 1626
- Views: 572501
Re: 8x16 and whatever else unreg wants to know
Not exactly sure of what you want, but it really looks like you want indirection. With indirect indexed addressing mode (like in lda (zp), y instruction), you can have a pointer in zero page and change it to point to a fruit. Your routines can then use the zero page pointer to do their work. Prior t...
- Sat Jul 09, 2022 5:37 am
- Forum: NESemdev
- Topic: "Fake" FF opcode vs a real one
- Replies: 5
- Views: 1222
Re: Fake FF opcode vs a real one
Not only a ROM can be partially full, there can be data intermingled with instructions, usually after a flow control instruction (jsr, rts, jmp etc) so the data won't be executed by the CPU. It is common to embed lookup tables alongside routines. And of course, usually well separated of the code, th...
- Tue May 17, 2022 8:25 pm
- Forum: NES Music
- Topic: FDS unable to utilize the DPCM channel?
- Replies: 11
- Views: 1931
Re: FDS unable to utilize the DPCM channel?
Couldn't it be that some of the BIOS routines are timing sensitive and would be thrown off by "unpredictable" DPCM DMA fetches?
- Fri May 06, 2022 6:58 pm
- Forum: NES Hardware and Flash Equipment
- Topic: Damaged PPU on top loader
- Replies: 51
- Views: 4280
Re: Damaged PPU on top loader
That's simply hexadecimal. $0400 == 1024 == 2^10. Other notation for hexadecimal is 400h or 0x400 (C, Python and other contemporary programming languages use the latter). $400 is simply 1 followed by 10 zeros in binary; in other words, in the context of address bits, A10 would be 1 and all the other...
- Mon Apr 25, 2022 3:37 am
- Forum: NES Hardware and Flash Equipment
- Topic: Damaged PPU on top loader
- Replies: 51
- Views: 4280
Re: Damaged PPU on top loader
That may sound stupid, but have you tried using a small ceramic capacitor (100nF) in parallel with your 4.7μF?
- Sat Feb 26, 2022 3:20 pm
- Forum: NESdev
- Topic: Glitch-free controller reads with DMC?
- Replies: 113
- Views: 84636
Re: Glitch-free controller reads with DMC?
That's just ... Regular FM basses?Ben Boldt wrote: ↑Fri Feb 25, 2022 7:02 pm Unrelated, but Shanghai II was an arcade game:
https://www.youtube.com/watch?v=ieZ1GgQ00oM
Who knew that? I had no idea. This might even be where the Sunsoft bass samples came from.
- Sat Feb 19, 2022 4:35 pm
- Forum: NESdev
- Topic: Glitch-free controller reads with DMC?
- Replies: 113
- Views: 84636
Re: Glitch-free controller reads with DMC?
Not that I know of, and I don't see why it would.
- Sat Feb 19, 2022 11:19 am
- Forum: NESdev
- Topic: Glitch-free controller reads with DMC?
- Replies: 113
- Views: 84636
Re: Glitch-free controller reads with DMC?
Yeah but page crossing due to normal PC incrementation has no special effect, only for (taken) branches. And the effect is not just one more CPU cycle, it affects interrupt timing... Though now that I read it, the IRQ/NMI is delayed when not crossing pages on taken branches...
- Sat Feb 19, 2022 8:58 am
- Forum: NESdev
- Topic: Glitch-free controller reads with DMC?
- Replies: 113
- Views: 84636
Re: Glitch-free controller reads with DMC?
IIRC, if the branch instruction is the last of its page, there's no forward page crossing, because then PC point to the new page after fetching the instruction?