[comp.unix.questions] problems to connect the serial line printer MT490 to a 4.3BSD VAX

din@pbinfo.UUCP (Dietmar Neuwoehner) (08/25/87)

We have problems to connect the serial printer MT490 to our VAX 11/750,
which runs 4.3BSD Unix.

The printer works until it gets an input buffer overflow. We know that
it sends xoff about 500 times until the overflow happens. The VAX ignores 
that sending more and more data.

This is the entry in our printcap file:

lpw|pbinfow|vaxw line printer MT490:\
	:lp=/dev/ttyA2:br#9600:fs#06360:xs#40:tr=\f:pl#72:pw#80:\
	:lf=/usr/adm/lpd-errs:sd=/usr/spool/lpd-pbinfow:

We tested the same serial port with a VT100 terminal and an entry in
/etc/ttys. It works.

Please tell us, if you know how to solve the problem.

Dietmar Neuwoehner


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hls@oce-rd1.UUCP (09/01/87)

In article <501@pbinfo.UUCP> din@pbinfo.UUCP (Dietmar Neuwoehner) writes:
>We have problems to connect the serial printer MT490 to our VAX 11/750,
>which runs 4.3BSD Unix.
>The printer works until it gets an input buffer overflow. We know that
>it sends xoff about 500 times until the overflow happens. The VAX ignores 
>that sending more and more data.
>This is the entry in our printcap file:
>lpw|pbinfow|vaxw line printer MT490:\
>	:lp=/dev/ttyA2:br#9600:fs#06360:xs#40:tr=\f:pl#72:pw#80:\
>	:lf=/usr/adm/lpd-errs:sd=/usr/spool/lpd-pbinfow:
>Please tell us, if you know how to solve the problem.

Some time ago we had the same problem connecting an Apple LaserWriter to
a VAX 8600. The laser printer produced only rubbish when we tried to
send some output to it using the lpr command.
For some reason there was no form of flow control between the 
laser printer and the VAX.
The output of the command "stty everything > /dev/ttyxx" (in your
case /dev/ttyA2) was very informative about the cause of our problem.
Default mode for the port we were using was "raw"-mode!!!
Extending the printcap-entry with :fc#040: solved our problem.

Harry Schreurs

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