I have a question regarding membler's NES register/memory test program. You can find it here:
http://nesdev.com/test.zip
I think there may be a bug in it. When I run this on my emulator, no matter what value I enter into any register the program _always_ writes all 1's to register $4015. You don't even have to change anything after boot up and you don't even have to have address $4015 listed on the screen. Just load the ROM and press 'B' (which is apparently how you're supposed to say, "Go write the data I entered").
It's really weird, it just always writes 11111 to bits [4:0] (the only bits used in $4015 writes) no matter I do. I suppose it could be something wrong with my emulator but I can't see what would be causing something so incorrect as this. And I also tested writing to the $40XX registers with my own test ROM and did not see this problem.
Can someone verify that they see/have the same issue? I don't know of a software emulator that will show you the state of the memory/registers its using. Is there one that does this?
Pz!
Jonathon
http://nesdev.com/test.zip
I think there may be a bug in it. When I run this on my emulator, no matter what value I enter into any register the program _always_ writes all 1's to register $4015. You don't even have to change anything after boot up and you don't even have to have address $4015 listed on the screen. Just load the ROM and press 'B' (which is apparently how you're supposed to say, "Go write the data I entered").
It's really weird, it just always writes 11111 to bits [4:0] (the only bits used in $4015 writes) no matter I do. I suppose it could be something wrong with my emulator but I can't see what would be causing something so incorrect as this. And I also tested writing to the $40XX registers with my own test ROM and did not see this problem.
Can someone verify that they see/have the same issue? I don't know of a software emulator that will show you the state of the memory/registers its using. Is there one that does this?
Pz!
Jonathon