Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!hplabs!hpl-opus!hpspdra!ric
From: ric@hpspdra.HP.COM (Ric Peregrino)
Newsgroups: comp.sys.amiga.tech
Subject: Help, MIDI data dumps
Message-ID: <13580006@hpspdra.HP.COM>
Date: 11 Mar 91 23:05:47 GMT
Organization: HP Stanford Park - Palo Alto, CA
Lines: 20


  Concerning MIDI sample data dumps:

  I have an A2000 1.3 with a program to send and receive MIDI sample
data dumps. It's not pretty, but I'd like to make it so. The ugliness
is that I Disable/Enable around a RBF (TBE for send) polling loop, thus
taking over the machine. What I would like to do is have a RBF interupt
service routine that **DOESN'T MISS A BYTE**. Sending is not a problem.

  The problem is MIDI 31250 BAUD; 8bits, 1 start, 1 stop; 320uS/data.
So I've got to get the data and be ready for the next data in 320uS.
The question I pose is how long (in CPU clock cycles) does it take
from a RBF interupt to when my service routine gets control of CPU,
in the worst case (I guess you need the operating system source code
to answer this). I noticed the hardware priority for the RBF is 6;
can any other interupt override this? If so, all hope is lost.

ric@hpspd