Search found 3831 matches

by Memblers
Fri Sep 18, 2020 10:55 am
Forum: NESdev
Topic: VBCC Optimizing C-compiler now supports NES
Replies: 155
Views: 24677

Re: VBCC Optimizing C-compiler now supports NES

I've had the uncanny experience of "getting beaten" by this compiler. I have a function that is simple but running very often, so I tried rewriting the main part of it in asm. It turned out slower than the C version, by more than just the JSR/RTS penalty from calling the asm subroutine. The asm rout...
by Memblers
Thu Sep 17, 2020 2:05 am
Forum: General Stuff
Topic: Famicomstation questions.
Replies: 2
Views: 123

Re: Famicomstation questions.

The only manuals I've seen look like one they'd leave in the hotel room for the user, there probably is a service manual somewhere though, I don't know if it's been found. I'd imagine the circuit would be pretty similar to the NES schematic though, with the extra stuff bolted on. https://problemkapu...
by Memblers
Thu Sep 17, 2020 1:45 am
Forum: NES Music
Topic: VRC7/YM2413/OPLL Custom Patches
Replies: 13
Views: 311

Re: VRC7/YM2413/OPLL Custom Patches

Seems like it should be possible to rip patches from a VGM file . I'm assuming the parameters don't/can't changed while the note plays (I'm not well-versed in the Yamaha stuff), one could store the channel's current register settings when a note-on is triggered. Discarding duplicate sets, and parsin...
by Memblers
Fri Sep 11, 2020 11:03 am
Forum: Newbie Help Center
Topic: CC65 interop with assembly
Replies: 3
Views: 265

Re: CC65 interop with assembly

This link also has info on the built-in functions, popa, popax, etc. (I know it's linked the in other article, but in case anyone missed that) https://github.com/cc65/wiki/wiki/Parameter-and-return-stacks I don't have a ton of experience doing this, but I did successfully use parameters in this proj...
by Memblers
Sun Sep 06, 2020 2:56 am
Forum: phpBB Issues
Topic: The [code] tag should not have its height limited
Replies: 9
Views: 871

Re: The [code] tag should not have its height limited

So we need to get in contact with WhoaMan somehow to fix this? Yes, that's the only way now. Previous version of phpBB used to allow editing through the admin control panel, but it only saved to a cached copy. Next time someone hits the "flush cache" button (or whatever else could cause that), the ...
by Memblers
Mon Aug 31, 2020 5:20 pm
Forum: General Stuff
Topic: Strange Contra glitch?
Replies: 4
Views: 459

Re: Strange Contra glitch?

Non-fatal CPU glitches can happen, I think I've seen a few of them, but it's really rare to do something other than immediately crash. Maybe take a look at Contra's IRQ/BRK vector? Capcom games like to point it to the reset, some stuff just points to an RTI. Tecmo Bowl has a debug screen on BRK that...
by Memblers
Sat Aug 29, 2020 6:34 am
Forum: NESdev
Topic: VBCC Optimizing C-compiler now supports NES
Replies: 155
Views: 24677

Re: VBCC Optimizing C-compiler now supports NES

Does sprintf (or any other function needing vargs) not work at the moment / not work at all? It seems to copy the format string if there are no placeholders and no vargs supplied, but otherwise appears to do nothing at all. I really don't even need sprintf, I just need a quick way to convert an int...
by Memblers
Wed Aug 26, 2020 7:33 pm
Forum: SNESdev
Topic: SuperCIC for PIC10F322
Replies: 34
Views: 7545

Re: SuperCIC for PIC10F322

I mentioned this problem to kevtris, and he had some suggestions: - check PIC config bits, and make sure power-up delay is turned off. Could be that the SNES and SNES Jr. have different reset lengths, and the PIC wasn't out of reset yet. - use provided hex file rather than build from source. Microch...
by Memblers
Mon Aug 24, 2020 3:07 am
Forum: General Stuff
Topic: Looks like NESCartDB is down (again)...
Replies: 56
Views: 21963

Re: Looks like NESCartDB is down (again)...

If it helps to have a simple list (for NES only), there's always the old boardtable.txt
https://wiki.nesdev.com/w/index.php/Board_table
by Memblers
Sun Aug 23, 2020 6:54 am
Forum: Newbie Help Center
Topic: How is this possible?
Replies: 7
Views: 782

Re: How is this possible?

Are you saving and restoring registers in your interrupt handlers by pushing them to and pulling them from the stack? If not, then if an interrupt occurs between these instructions, your registers will likely be clobbered. Yeah, I think it's that. And if the NMI is itself being interrupting by anot...
by Memblers
Fri Aug 21, 2020 9:38 pm
Forum: Other Retro Dev
Topic: Zsnes savestate file format
Replies: 17
Views: 1136

Re: Zsnes savestate file format

Is there an SNES emu that will let you view the contents of palette RAM? If so, copy a sequence of values, and search for them in a save state from the same screen.
by Memblers
Fri Aug 21, 2020 1:31 am
Forum: NESdev
Topic: KickC Optimizing C-Compiler now supports NES
Replies: 22
Views: 5806

Re: KickC Optimizing C-Compiler now supports NES

It is some incredible timing, I don't think have been new C compilers for decades. I think the difference is that VBCC is a mature compiler with a new 6502 backend, while KickC is an all-new 6502-specific compiler. It's really interesting, seeing all the code fragments and how you can add new ones. ...
by Memblers
Sat Aug 15, 2020 5:47 pm
Forum: NESdev
Topic: VBCC Optimizing C-compiler now supports NES
Replies: 155
Views: 24677

Re: VBCC Optimizing C-compiler now supports NES

Btw. if you declare the function pointer arrays like this static void (*const addrtable[256])() = { ... static void (*const optable[256])() = { then they will be placed in ROM only rather than being copied from ROM to RAM. Thanks for the tip, changing those to const does fix it, and with that fake6...
by Memblers
Fri Aug 14, 2020 7:58 am
Forum: Homebrew Projects
Topic: listen to a 6502 emulate a 6502 emulating a 6502
Replies: 1
Views: 662

listen to a 6502 emulate a 6502 emulating a 6502

One of the more absurd programs I've put together, this demo uses fake6502 by miker00lz, compiled with cc65, to emulate a 6502. The emulated 6502 remaps NES internal RAM to $7000 and a portion of $6000+ (that cc65 uses) to $7800. This emulated 6502 boots from the ROM's own reset vector, which in tur...
by Memblers
Thu Aug 13, 2020 4:55 pm
Forum: NESdev
Topic: VBCC Optimizing C-compiler now supports NES
Replies: 155
Views: 24677

Re: VBCC Optimizing C-compiler now supports NES

Thanks for getting it to build, lazycow. My cat also likes this demo, haha. I did notice another thing in lnAddSpr that could be optimized, maybe a little controversial though. The INX INX INX INX sequence could be replaced with TXA / AXS #$FC unofficial opcode (it trashes A, but the loop trashes it...