From my understanding both set the bit 4 of the console port so it should be the same.
I'm testing with zapper_stream rom of rainwarrior from https://forums.nesdev.com/viewtopic.php?f=9&t=13021 with Mesen, Bizhawk, FCEUX.
If i select a zapper for the port 2, the rom works as expected and detect the trigger pulling but if i select a second gamepad and press Up button nothing happens. So it must have something wrong in my understanding.
Can someone help me pointing out the issue pls?
Thanks!
[Solved]What is the difference between zapper trigger and Up
Moderator: Moderators
[Solved]What is the difference between zapper trigger and Up
Last edited by geod on Tue Apr 16, 2019 1:56 am, edited 1 time in total.
3dSen - Play NES games in 3D & VR
http://www.geodstudio.net/
http://www.geodstudio.net/
Re: What is the difference between zapper trigger and Up?
The standard controller does not give you all the bits simultaneously. When you read $4016 or $4017, you only get one button at a time, and that from the least significant bit.
The zapper, in contrast, only has 2 "buttons", and those are received simultaneously. (Unless you're on the Vs. System)
The zapper, in contrast, only has 2 "buttons", and those are received simultaneously. (Unless you're on the Vs. System)
Re: What is the difference between zapper trigger and Up?
I get it now, thank you 

3dSen - Play NES games in 3D & VR
http://www.geodstudio.net/
http://www.geodstudio.net/