On Thu, 26 Aug 1999, Jaroslav Kysela wrote:
>> > A 100% CPU usage for 1sec ?
> > I can't believe this.
>
> Try it.
>
> linux/drivers/sound/mpu401.c:
>
> /*
> * Sometimes it takes about 30000 loops before the output becomes ready
> * (After reset). Normally it takes just about 10 loops.
> */
>
> for (timeout = 30000; timeout > 0 && !output_ready(devc); timeout--);
arrgh, really bad !
> > 200bytes/sec is just rudiculous , how do you plan to drive an external synth
> > with that little MIDI bandwidth ?
>
> I need a timer around 2000Hz for some good code. I won't support polling
> mode (busy loop) in any case.
Yes, is there some free timer available in Linux to perform this job ?
It would be nice to be able to use the full MIDI bandwidth without eating
all the CPU power.
>
> > Many songs uses up much of the 3000 bytes/sec bandwidth, especially
> > when there are many controller/pitchbend events present.
> >
> > Do you know if the RX FIFO of the MPU401 has the same problem (no interrupt) or
> > is there an interrupt present ?
>
> No, MPU401 has Rx interrupt.
Fortunately ! , this means you can still use your PC as a realtime synth/sampler
when played through a MIDI masterkeyboard
>
> > Does this mean that sequencers running under Windows have the same problems
> > as we in Linux on the AWE64 ?
>
> I don't know, how is this problem solved under W$.
>
> Jaroslav
certainly in a sub-optimal way.
:-)
regards,
Benno.
