Change the sematics of callirq and the existing interruptors: The interrupts

must now return carry set if the interrupt has been handled, and carry clear
if not. The callirq routine will stop calling handlers with the first handler
that claims to have handled the interrupt. callirq will return the carry flag
to the caller as it came from the last interruptor called.


git-svn-id: svn://svn.cc65.org/cc65/trunk@3491 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/c64/c64-hitjoy.s

@@ -79,8 +79,10 @@ UNINSTALL:
         rts
 
 ; ------------------------------------------------------------------------
-; IRQ entry point. Is called from the C layer as a subroutine in the 
-; interrupt.
+; IRQ entry point. Is called from the C layer as a subroutine in the
+; interrupt. The routine MUST return carry set if the interrupt has been
+; 'handled' - which means that the interrupt source is gone. Otherwise it
+; MUST return carry clear.
 
 IRQ:    ; cia 2 setup
 
@@ -156,6 +158,8 @@ fire:
         lda     #0
         sta     $dc04
 
+        ; We do never "handle" the interrupt, we use it just as a timer.
+        clc
         rts
 
 ; ------------------------------------------------------------------------