diff --git a/c64/kernal/ioinit.s b/c64/kernal/ioinit.s index 64047b7a..46998862 100644 --- a/c64/kernal/ioinit.s +++ b/c64/kernal/ioinit.s @@ -20,10 +20,13 @@ ioinit: lda #$7f sta $DC0D ; First disable all - ;; Set timer interval to ~1/50th of a second - lda #<20000 + ;; Set timer interval to ~1/60th of a second + ;; (This value was calculated by running a custom IRQ haandler on a C64 + ;; with original KERNAL, and writing the values of $DC04/5 to the screen + ;; in the IRQ handler to see roughly what value the timers must be set to) + lda #<16380 sta $dc04 - lda #>20000 + lda #>16380 sta $dc05 ;; Enable timer interrupt