Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!pt.cs.cmu.edu!f.word.cs.cmu.edu!eht
From: eht@f.word.cs.cmu.edu (Eric Thayer)
Newsgroups: comp.sys.next
Subject: Re: YADSPQ (Yet Another DSP Question)
Message-ID: <5420@pt.cs.cmu.edu>
Date: 5 Jul 89 11:12:35 GMT
References: <11494@orstcs.CS.ORST.EDU>
Organization: Carnegie-Mellon University, CS/RI
Lines: 18

DSPBootFile() opens the dsp in a mode such that if the MSB of the data in the
HTX is high, the DSP driver interprets this as an error code.  Hence the
garbled data for half of the cycle.

I sent NeXT a bug report about this one and they sent me a work around.  I'll
post their work around when when I get into work.

And as you've noticed, the I/O throughput of the standard calls is not so
good.  There are better ways to do I/O (dsprecord uses them for instance), but
so far I have not been able to see any example code for it.

DSP coding on the NeXT requires perseverance.  Also ping ask_next about these
things so corporate NeXT is made aware of the issues they have to address.


-- 
Eric H. Thayer		Carnegie Mellon School of Computer Science
(412) 268-{8724,6973}	5000 Forbes Ave, Pittsburgh, PA 15213