Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!hellgate.utah.edu!helios.ee.lbl.gov!ux1.lbl.gov!beard
From: beard@ux1.lbl.gov (Patrick C Beard)
Newsgroups: comp.sys.mac.programmer
Subject: Serial Drivers @ Interrupt Time
Summary: Receiving Data/How Much To Read?
Keywords: Serial, Interrupts
Message-ID: <4134@helios.ee.lbl.gov>
Date: 3 Nov 89 18:44:15 GMT
Sender: usenet@helios.ee.lbl.gov
Reply-To: beard@ux1.lbl.gov (Patrick C Beard)
Organization: Lawrence Berkeley Laboratory, Berkeley
Lines: 19

Hi NetLand.

I am attempting to use the serial drivers at VBL time.  One question
I have is how to ask the input serial driver how much data it currently
has in its input buffers.  Inside Macintosh states that the calls PBStatus
and PBControl may move memory, and yet PBStatus is the call I need to make
to find out the number of bytes in the serial driver buffer.  How do I do it?
I find that posting asynchronous reads is very inefficient (how many bytes
to read is the hardest thing to come up with) and was wondering if there
is a more direct way to ask the serial driver how many bytes are in the
buffer I give it.

Thanks.


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-  Patrick Beard, Macintosh Programmer                        (beard@lbl.gov) -
-  Berkeley Systems, Inc.  ".......<dead air>.......Good day!" - Paul Harvey  -
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