Search found 4 matches

by mr_cannoli
Tue May 26, 2020 11:02 pm
Forum: Newbie Help Center
Topic: Can NMI while you're inside the NMI handler?
Replies: 4
Views: 1166

Re: Can NMI while you're inside the NMI handler?

Some games do that, but unfortunately, there's a bug in the PPU that causes a graphical glitch if a write to $2000 happens at certain times.
Fascinating read, thanks guys!
by mr_cannoli
Tue May 26, 2020 9:51 pm
Forum: Newbie Help Center
Topic: Can NMI while you're inside the NMI handler?
Replies: 4
Views: 1166

Can NMI while you're inside the NMI handler?

I'm sure this is posted somewhere, but I wasn't able to find it. I'm working on a small project where the main for my game is in NMI. It got me thinking, is it possible if your NMI runs too many instructions, could the NMI interrupt again while you're already executing code? If so would the remedy j...
by mr_cannoli
Mon Apr 27, 2020 6:16 pm
Forum: Newbie Help Center
Topic: Questions on CLC/SEC and general NMI logic
Replies: 6
Views: 1106

Re: Questions on CLC/SEC and general NMI logic

ADC with carry set will add value+1 . The same goes for SBC with carry clear. If you don't know the state of the carry flag beforehand, you should set or clear it depending on the operation you are performing. Without the CLC/SEC, you were probably moving by 2 each frame instead of 1 as you intende...
by mr_cannoli
Mon Apr 27, 2020 5:51 pm
Forum: Newbie Help Center
Topic: Questions on CLC/SEC and general NMI logic
Replies: 6
Views: 1106

Questions on CLC/SEC and general NMI logic

Hi there! First time poster here, hopefully I'm following this forums formatting rules so feel free to let me know otherwise. I'm following the Nerdy Nights tutorials and just finished putting my first sprite on the screen. I gave myself the challenge to see if I can move the sprite back and forth a...