Keyboard input problem
Posted: Tue Aug 22, 2023 1:26 pm
Hello everyone.
I'm writing a program in assembly that requires recurrent inputs from the keyboard.
Having no idea of how to manage that directly, I used the GETIN function from the kernal and everything worked pretty well, so far.
But now I need to switch the IRQ trigger to a certain screen line, so I added this to my code:
Result: GETIN doesn't work anymore.
No keyboard input seems to be considered.
Any idea of what's going on?
Is GETIN tied to VSYNC (line zero) IRQ trigger? If so, I wonder why...
I also tried to load IEN with $83 (which activates VSYNC IRQ as well), but nothing changes.
I'm puzzled.
Thanks for your help,
Giacomo
I'm writing a program in assembly that requires recurrent inputs from the keyboard.
Having no idea of how to manage that directly, I used the GETIN function from the kernal and everything worked pretty well, so far.
But now I need to switch the IRQ trigger to a certain screen line, so I added this to my code:
Code: Select all
; Make VERA generate IRQs at line 447
LDA #$82
STA $9F26 ; IEN
LDA #$BF
STA $9F28 ; IRQline
No keyboard input seems to be considered.
Any idea of what's going on?
Is GETIN tied to VSYNC (line zero) IRQ trigger? If so, I wonder why...
I also tried to load IEN with $83 (which activates VSYNC IRQ as well), but nothing changes.
I'm puzzled.
Thanks for your help,
Giacomo