Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!sol.ctr.columbia.edu!emory!hubcap!ncrcae!sauron!stevem
From: stevem@sauron.Columbia.NCR.COM (Steve McClure)
Newsgroups: comp.sys.m68k
Subject: Re: Need help connecting m68k to a UNIX box.
Message-ID: <2254@sauron.Columbia.NCR.COM>
Date: 31 Jul 90 12:36:38 GMT
References: <14703@unix.SRI.COM>
Reply-To: stevem@sauron.UUCP (Steve McClure)
Distribution: na
Organization: E&M-Columbia, NCR Corp, W Columbia, SC
Lines: 38

In article <14703@unix.SRI.COM> henry@ginger.sri.com (Henry Pasternack) writes:
+
+   This is technically a UNIX question, but I have this paranoid 
+feeling that posting to a UNIX bulletin board would be an exercise
+in futility.  Perhaps someone over here can help me out.
+
+   Problem: My 68000 board is running now, and I'm successfully
+programming it in C using the Sun3 compiler.  I've written a two-part
+communications program for the purpose of downloading S-record code
+from a SPARCStation to the 68000.  I use kermit to provide terminal
+emulation over the Sun's 'ttya' port.  The 'ttyb' port is driven by
+my communications program which listens for file requests from the 
+client and dumps S-records on command.
+
+   I'm having a lot of trouble getting the interface to '/dev/ttyb'
+to work.  I admit to knowing virtually nothing about UNIX I/O, and
+the reference manuals aren't much help.  The port already seems to be
+configured for 9600 baud, which is convenient.  I do an 'fopen' on
+'/dev/ttyb' and use 'gets' and 'fprintf' to perform I/O.  The Sun
+has no problem receiving command lines from the client, but when the
+client begins polling for a response after sending a request, it gets
+a garbled copy of its request back.  It seems as though the buffer
+UNIX is creating is bidirectional, rather than dual-unidirectional.
+
+   Can anyone give me an understandable explanation of how to set
+up my SPARCStation to do simple and effective I/O to the serial ports?
+

I wrote some PROM Programmer software for a Unix box and ended up opening
a read-only file and a write-open file on the same port.  This same technique
is used in the Unix cu command so I assume it is pretty much standard.  Hope
this helps.

-- 
----------------------------------------------------------------------
Steve		email: Steve.McClure@Columbia.NCR.COM	803-791-7054
The above are my opinions, which NCR doesn't really care about anyway!
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