Search found 45 matches
- Wed Oct 24, 2018 7:20 am
- Forum: NES Hardware and Flash Equipment
- Topic: MMC5 Hacking Adventures
- Replies: 339
- Views: 178062
Re: MMC5 Hacking Adventures
I don't need to stay with my current design -- I am open to ideas. I wish I had a 100 pin, 5 Volt microcontroller and skip these stupid IO expanders, they are so slow. It's not 100 pins, but the Arduino Mega 2560 rev 3 has 54 I/Os at 5V. (The ATmega2560 chip it uses has 86 I/Os, but the Arduino is ...
- Sun Sep 09, 2018 1:28 pm
- Forum: General Stuff
- Topic: C(++) and binary data annoyance
- Replies: 15
- Views: 7956
Re: C(++) and binary data annoyance
Why do you have to swap the bits with different endians? Shouldn't you only be swapping the bytes? I think the compiler developers could have decided to keep bit-order within bytes the same between little and big endian code, but they decided instead to make the bit-order behave like the byte-order...
- Sat Sep 08, 2018 6:57 pm
- Forum: General Stuff
- Topic: C(++) and binary data annoyance
- Replies: 15
- Views: 7956
Re: C(++) and binary data annoyance
I use bitfields all over the place in my emulator, in a way very similar to yours. I use them in the core CPU and PPU emulation, I use them in mapper registers, I use them in iNES and FDS header parsers. That advice about non-portable or compiler-specific behavior? Yeah, the standard might say that,...
- Fri Aug 17, 2018 1:29 pm
- Forum: NESdev
- Topic: Finding JSRs in PRG ROMs
- Replies: 8
- Views: 3761
Re: Finding JSRs in PRG ROMs
Thanks everyone for replying so quickly! If you find errors in the wiki please point them out and we'll fix them. Of course. I plan to submit fixes once I have completed my investigation. Perhaps my old FDS-Explorer might come in handy? Thank you for calling it to my attention. I will definitely che...
- Fri Aug 17, 2018 12:34 pm
- Forum: NESdev
- Topic: Finding JSRs in PRG ROMs
- Replies: 8
- Views: 3761
Finding JSRs in PRG ROMs
I'm trying to do some static analysis of FDS titles, identifying and counting which FDS BIOS APIs they call. Following the classic strategy of "do the simplest thing that could possibly work," my first attempt just scanned the ROM for byte sequences of $20 $xx [$Ex|$Fx], in other words, "JSR $Exxx" ...
- Thu Jul 26, 2018 9:21 am
- Forum: NESemdev
- Topic: Latest version of Nes_Snd_Emu code?
- Replies: 0
- Views: 9583
Latest version of Nes_Snd_Emu code?
The latest version of Nes_Snd_Emu available from blargg's website is 0.1.7, while his Game_Music_Emu library has Nes_Snd_Emu version 0.1.8 files in it. Are these the latest? Has blargg or another emulator author made any significant enhancements or fixes to Nes_Snd_Emu that are located somewhere els...
- Fri Feb 02, 2018 7:43 am
- Forum: NESemdev
- Topic: Question about nestopia MMC5 emulation
- Replies: 17
- Views: 11358
Re: Question about nestopia MMC5 emulation
MMC5 has mapper-controllable mirroring. Altering the mirroring bits in the iNES header won't affect emulation.
- Fri Dec 29, 2017 7:14 am
- Forum: NESdev
- Topic: Strategies for dealing with the four sprite palette limit?
- Replies: 37
- Views: 13547
Re: Strategies for dealing with the four sprite palette limi
So, I'm finding myself shocked and bamboozled by how darn few sprite palettes you can have at once. It's just four! It's not like I didn't know that beforehand, but now that I'm actually coding up my project I'm struck by how little four actually turns out to be. I'm making a co-op kinda thing, so ...
- Mon Aug 21, 2017 7:03 am
- Forum: NESemdev
- Topic: iNES header: size 255 == 256?
- Replies: 14
- Views: 7593
Re: iNES header: size 255 == 256?
Instead of re-interpreting bits that have already been defined, it would be easier to simply take advantage of the still-reserved bytes in the header. Bytes 14 and 15 are still undefined. If Byte 14's 8 bits were defined to be bits 13-20 of the PRG size field, then NES 2.0 would be able to specify 1...
- Tue May 02, 2017 7:38 pm
- Forum: NESemdev
- Topic: Sprite 0 hit, scroll splits, and fineX
- Replies: 5
- Views: 3576
Re: Sprite 0 hit, scroll splits, and fineX
Thanks for the help, everyone. It turns out that while I was testing the correct pixels, including the 1 line delay for the sprite position, I forgot to include that 1 line delay when I returned the hit location. Oops.
One more bug squished, countless more to go...
One more bug squished, countless more to go...
- Tue May 02, 2017 11:36 am
- Forum: NESemdev
- Topic: Sprite 0 hit, scroll splits, and fineX
- Replies: 5
- Views: 3576
Re: Sprite 0 hit, scroll splits, and fineX
Thank you for helping me work this out! If fine X is 7, and $2005 first write is written again with the same coarse X and fine X of 0, then the 7 most recently rendered background pixels will be rendered again. The scenario in SMB1 is the reverse - the fineX is 0 for the status bar, and then after t...
- Mon May 01, 2017 8:32 pm
- Forum: NESemdev
- Topic: Sprite 0 hit, scroll splits, and fineX
- Replies: 5
- Views: 3576
Sprite 0 hit, scroll splits, and fineX
Games like Super Mario Bros. and Zelda 2 put sprite 0 at the bottom-center of their status bars and then test for sprite 0 hit to know when to set a non-zero xScroll in $2005, right? In my emulator, the right half of that scanline is glitched, messing with the bottom pixels of the count counters and...
- Tue Aug 02, 2016 6:53 am
- Forum: SNESdev
- Topic: 65816 really 16 bit or just a 6502 with 16 bit registers
- Replies: 126
- Views: 37156
Re: 65816 really 16 bit or just a 6502 with 16 bit registers
The SNES, on the other hand, has only one true weakness - the inexcusably slow CPU. Once again, this statement complete and utter bullshit. Since this thread seems to be inspiring fanboi rage, let me start by saying that the SNES is my favorite console of the 16-bit generation, by a very long shot....
- Mon Aug 01, 2016 2:54 pm
- Forum: SNESdev
- Topic: 65816 really 16 bit or just a 6502 with 16 bit registers
- Replies: 126
- Views: 37156
Re: 65816 really 16 bit or just a 6502 with 16 bit registers
The Saturn is very complex, convoluted but at least it doesn't have real weakness as the SNES can have. This is from an old part of the conversation, but I really can't let it slide. The Saturn has multiple weaknesses that stem from atrocious design decisions. The SNES, on the other hand, has only ...
- Tue Mar 29, 2016 2:52 pm
- Forum: NESdev
- Topic: Reasonable implementation of PCM
- Replies: 20
- Views: 7070
Re: Reasonable implementation of PCM
Disadvantages: MMC5 is not cloned in a CPLD yet And the FME-7 is cloned? That's the mapper za909 is talking about using. Disadvantages: Mapper audio does not play back on unmodified 72-pin consoles On this forum, given how many folks are PowerPak users and FDS aficionados, I figured most everybody ...