Path: utzoo!attcan!uunet!jarthur!usc!samsung!sdd.hp.com!decwrl!ucbvax!applelink.apple.com!D1749
From: D1749@applelink.apple.com (Disini SW, Emmanuel Disini,PRT)
Newsgroups: comp.protocols.appletalk
Subject: adsp problems
Message-ID: <6977508@AppleLink.Apple.COM>
Date: 3 Sep 90 14:15:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 14

Hi.  We seem to be having problems with ADSP over here. Whenever we receive
serial data (at speeds of 9600 baud or higher) on a MacPlus running an ADSP
session, some SCC hardware overruns occur.  It seems that ADSP is turning off
interrupts for a pretty long time (at least 3.12 ms), so that the SCC's 3 byte
buffer is filled.  I can receive serial data with no overruns at 19200 bps even
when heavy-duty AFP, ATP, or DDP traffic is going on, so we know it isn't a
problem with Mpp.  It isn't a floppy drive problem either because I've
experienced no serial data losses at 57600 bps while erasing a floppy (on the
same Mac that's receiving the serial data).  It *definitely* isn't a problem
with our code turning off interrupts, or some other INIT/CDEV.  Has anyone ever
encountered this problem at all?
 
Joel Disini