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From: mason@Unify.Com (Mark Mason)
Newsgroups: comp.sys.m68k
Subject: Re: Need help connecting m68k to a UNIX box.
Message-ID: <hwg3h0m@Unify.Com>
Date: 1 Aug 90 23:25:35 GMT
References: <14703@unix.SRI.COM> <2254@sauron.Columbia.NCR.COM>
Distribution: na
Organization: Unify Corporation, Sacramento, CA, USA
Lines: 39

In article <2254@sauron.Columbia.NCR.COM> stevem@sauron.UUCP (Steve McClure) writes:
>In article <14703@unix.SRI.COM> henry@ginger.sri.com (Henry Pasternack) writes:
[del...]
>+   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?
>+
[del...]

you need to do a fflush() on the stream before "changing direction"
(reading -> writing or writing -> reading).

like:
	fgets()
-->	fflush()
	fprintf()
-->	fflush()
	fgets()

etc.

Hope this helps.
mason
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mason@reed.bitnet forever!

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