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From: woof@psivax.UUCP (Hal Schloss)
Newsgroups: net.micro.pc
Subject: Re: Does DOS listen to LaserJets?
Message-ID: <663@psivax.UUCP>
Date: Sun, 18-Aug-85 13:52:26 EDT
Article-I.D.: psivax.663
Posted: Sun Aug 18 13:52:26 1985
Date-Received: Sat, 24-Aug-85 19:38:20 EDT
References: <596@alberta.UUCP> <13600015@hp-pcd.UUCP> <326@faron.UUCP>
Reply-To: woof@psivax.UUCP (Hal Schloss)
Organization: Pacesetter Systems Inc., Sylmar, CA
Lines: 24
Summary: 

In article <326@faron.UUCP> kbb@faron.UUCP (Kenneth B. Bass) writes:
>In article <13600015@hp-pcd.UUCP> john@hp-pcd.UUCP (john) writes:
>> This must be a case of software inertia in action. Actually I think the "few
>>chars" that are sent is caused by using a double buffered UART with software
>>testing of the DTR status. 
>
>This is a problem I've encountered practically every time I've had to
>interface any two serial devices.  That is, the problem of flow control.

Well I have had similar experiences connecting our VAX 11/750 to a HP
laserjet. The problem occurs with BSD 4.* for the same reasons as on MS-DOS.
The fix was to install a Microbuffer from Practical Peripherals. After
installing it as a "lump" in the cable all my problems went away. It responds
to the Laserjet very quickly and doesn't overflow the printer's buffer, and
the Microbuffer has enough buffer left when it sends a X-OFF as to not be a
problem.

-- 
		Hal Schloss
		(from the Software Lounge at) Pacesetter Systems Inc.
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