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From: garton@cunixa.cc.columbia.edu (Bradford Garton)
Newsgroups: comp.sys.next
Subject: Re: NeXT and Real-Time
Keywords: real time music mach ualarm paging operating system
Message-ID: <1990Mar1.043429.23935@cunixf.cc.columbia.edu>
Date: 1 Mar 90 04:34:29 GMT
References: <8196@pt.cs.cmu.edu>
Sender: usenet@cunixf.cc.columbia.edu (The Network News)
Reply-To: brad@woof.columbia.edu (Brad Garton)
Organization: Columbia University Electronic Music Center
Lines: 29

In article <8196@pt.cs.cmu.edu> jcd@maps.cs.cmu.edu (Jean-Christophe Dhellemmes) writes:
>Real-Time on the NeXT ?
>=======================
>
>I haven't used the 1ms timing facilities described in NeXT's Midi Library
>documentation, and this is the next tests I am going to do.

This may work, as I understand it by using the Midi object in "timed" mode
you are using a clock internal to the MIDI output driver.  Similarly, I
think that using the Orchestra in timed mode allows you to use the DSP
clock for event timing.

>Anyway, Mach is
>not a real-time system and in the current version will never guarantee that
>you can execute a function in time. Virtual memory and paging are
>high-priority kernel funtions and don't have a time limit for execution. So
>I doubt the NeXT's Midi stuff will give a perfect answer to my problem.

This may be true -- I don't know at what level these clocks compete.

>new to do real-time on the NeXT, and wether I can hope one day to develop
>SERIOUS musical software on the NeXT.

Does real-time necessarily == SERIOUS?  I guess csound, cmix, et. al.
are just for fun.  Well, at least I think so!

Brad Garton
Music Dept; Columbia University
brad@woof.columbia.edu