Search found 238 matches

by Fiskbit
Thu Sep 24, 2020 4:43 pm
Forum: Newbie Help Center
Topic: Sprites are jittery when moving, not moving smoothly
Replies: 13
Views: 2857

Re: Sprites are jittery when moving, not moving smoothly

The second ROM is the one I was debugging. I haven't looked at the first one. I suggest frame stepping so you can see everything halt for a frame from the behavior I described in the second ROM.
by Fiskbit
Thu Sep 24, 2020 3:43 pm
Forum: Newbie Help Center
Topic: Sprites are jittery when moving, not moving smoothly
Replies: 13
Views: 2857

Re: Sprites are jittery when moving, not moving smoothly

Your whole game pauses for a frame every few frames, which makes it jittery. This is because in the function where you wait for the NMI ($8350), after the NMI is detected, you check a counter in $02 to see if it's equal to #$05 or not. If it is, you spin until it's not #$05. $02 is incremented in th...
by Fiskbit
Thu Sep 24, 2020 12:53 am
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 596
Views: 266740

Re: Reverse Engineering the CIC

I believe CIC pins 1 and 2 are the ones that should be outputting your missing bits.
by Fiskbit
Wed Sep 23, 2020 7:09 pm
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 596
Views: 266740

Re: Reverse Engineering the CIC

I haven't seen anything yet that would make me think these are SM591 or SM595 chips. Even if they were, we should be getting the first field, and would know it's incomplete because the code in that field would have jump instructions referencing the other field.
by Fiskbit
Wed Sep 23, 2020 4:17 pm
Forum: NESemdev
Topic: Photo-Sensitive Epilepsy Safe NES/SNES Emulation?
Replies: 4
Views: 1942

Re: Photo-Sensitive Epilepsy Safe NES/SNES Emulation?

Mesen has Lua scripting ( see documentation ). It can write to palette RAM. It can also read/write the color of a given pixel or even the whole screenbuffer, apparently with 32-bit ARGB color. I think this is good enough to do what I've suggested, though it could get confused if there are two identi...
by Fiskbit
Wed Sep 23, 2020 4:06 pm
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 596
Views: 266740

Re: Reverse Engineering the CIC

Do you get that starting point without my changes but with the extra 256 clocks before ACL drops? That dump is starting at page 3, which is really weird. I wonder if the 256 instruction clocks before ACL drops are advancing the instruction pointer to get from page 1 (standby behavior) to page 3, but...
by Fiskbit
Wed Sep 23, 2020 2:52 pm
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 596
Views: 266740

Re: Reverse Engineering the CIC

Good find on the need for 2 instruction cycles for reset after power-on. I'll be curious to see if this resolves the problems we're seeing, though I'm not convinced it will remove the 1 instruction jitter. Note that our moving the sampling position was intended to keep it in the same part of the ins...
by Fiskbit
Wed Sep 23, 2020 1:29 pm
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 596
Views: 266740

Re: Reverse Engineering the CIC

I don't have the code on-hand at the moment, but the two changes I remember that aren't reflected in Jeroen's latest update are a single added ClockMacro() before lowering ACL: ClockMacro(); PORTC &= 0b11101111;// lower ACL and moving where dataArray is sampled, to compensate for the above change: f...
by Fiskbit
Wed Sep 23, 2020 1:21 pm
Forum: NESemdev
Topic: Photo-Sensitive Epilepsy Safe NES/SNES Emulation?
Replies: 4
Views: 1942

Re: Photo-Sensitive Epilepsy Safe NES/SNES Emulation?

(Sorry, didn't see this thread before responding in the Mesen one. Here's what I posted there:) I think you could automatically detect this with something along the lines of looking for large changes in a color histogram across adjacent frames, and doing some kind of effect when this is detected too...
by Fiskbit
Wed Sep 23, 2020 1:19 pm
Forum: NESemdev
Topic: Mesen - NES Emulator
Replies: 901
Views: 462442

Re: Mesen - NES Emulator

Sour is on indefinite break right now, but regarding the flashing, I think you could automatically detect this with something along the lines of looking for large changes in a color histogram across adjacent frames, and doing some kind of effect when this is detected too many times in a short window...
by Fiskbit
Wed Sep 23, 2020 3:10 am
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 596
Views: 266740

Re: Reverse Engineering the CIC

Worked on this some tonight with a friend. We were able to dump a 3193A and confirm that it matches the accessible 508 bytes of the existing 512 byte dump. We also tried to dump a 6113B1, but were unsuccessful. We used Jeroen's code with an Arduino Diecimila. If you're using an Arduino like this wit...
by Fiskbit
Tue Sep 22, 2020 4:21 pm
Forum: NESemdev
Topic: Mesen - NES Emulator
Replies: 901
Views: 462442

Re: Mesen - NES Emulator

Different serial registers have different ways of handling the serial writes. w is used specifically for the $2005 and $2006 PPU writes, which take 2 writes. You're correct that interrupts can be a big problem for serial registers; if the handler needs to use a serial register that is also used outs...
by Fiskbit
Tue Sep 22, 2020 3:55 pm
Forum: NESemdev
Topic: Mesen - NES Emulator
Replies: 901
Views: 462442

Re: Mesen - NES Emulator

Based on your edit, you mean w in the PPU? That's shown in the debugger as "Write Toggle", and yeah, you can see the state of w in the event viewer on $2005 and $2006 writes.
by Fiskbit
Tue Sep 22, 2020 3:09 pm
Forum: NES Hardware and Flash Equipment
Topic: Twin Famicom - Only discs shows messed up graphics
Replies: 7
Views: 2358

Re: Twin Famicom - Only discs shows messed up graphics

Does the issue correct itself after you leave the title screen? NESRGB has some kind of issue where palettes can be wrong shortly after reset. I often see this manifest as bad colors on the Zelda 1 title screen.
by Fiskbit
Tue Sep 22, 2020 1:52 pm
Forum: NES Hardware and Flash Equipment
Topic: Reverse Engineering the CIC
Replies: 596
Views: 266740

Re: Reverse Engineering the CIC

To be clear, it's the PRG and CHR ROMs on that cart I'm interested in, not the CIC (though I do think it's worth it to try dumping your other CICs in case it's damage and they didn't all suffer the same fate). I think the FamicomStation menu is currently undumped.