Re: A89: Re: delay routine


[Prev][Next][Index][Thread]

Re: A89: Re: delay routine




auto int 5 is an interrupt vector (assuming you know what an interrupt is)
that you can control the frequency of using port $600016 (the programmable
rate generator as it's called).  If ($600016) is set to -32, auto int 5 will
trigger after 32 68000 interrupts (5600Hz -- auto int 1 occurs every 4 68000
interrupts).  So setting this port to -32 and enabling the auto int 5 vector
will cause your int 5 handler to execute at a frequency of 5600Hz/32 or
175Hz.  By setting a flag in your interrupt handler to be checked in the
main loop of the program, you will be able to synchronize your game cycles
to execute at 175Hz (or whatever frequency you want).


>
> In a message dated 5/5/99 10:39:10 PM Pacific Daylight Time, dux@acz.org
> writes:
>
> > auto int 5 handler
>
>
> I keep hearing this, and I only have a slight idea what it is... at the
risk
> of sounding like a newbie, could I ask someone to explain what exactly an
> auto int 5 handler is? Perhaps I could do a TutoriCode(TM) about it....
^_^
>
>



References: