set up buffer for serial printer

In early versions on Unix I could put the following lines in the /etc/rc file to slow down the flow of data to a serial printer.

sleep 3
cat </dev/tty##&
stty ctsflow ixon 9600 </dev/tty##

(were ## is the port # where the printer is connected)

In Unix 3.2 V5.01  this causes the system to lock on boot when loading print services.

Use to work on earlier versions, or am I doing something wrong?
I have slowed the baud rate to 1200 and I can print long reports, but takes forever.
I need to get the speed back without loss of data.

Gerald
gmboothAsked:
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gheistCommented:
Stting both serial and data flow control might not be so great.
You have to determine what setting printer needs ( by asking remote site for digital photograph of printer's jumper board).

Some printers do automatically accept up to 9600, some 38400 some 115200 bps
Some do filter xon/xof some do not
Some do "even" parity - sometimes even undocumented.
Some need jumper switched for dts/cts.

Print /etc/motd with different settings.

i.e start with
9600 8N1
then
9600 8E1

Does it miss characters in either mode? - make it slower if changing cable does not help
Does it miss first characters in line beginning? - change printer
Does it miss bits (some chars altered) ? - change cable

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gheistCommented:
"uname -a" please.
Printer make & model please.

Your setting does not touch any serial buffering.

Serial data problems are most likely caused by bad serial cable and/or connections (probably inside computer/printer casings)
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gmboothAuthor Commented:
Hi gheist,

uname -a responds SCO-SV scosysv,  3.2  5.0.5 i386
The printers are Okidata 184 turbo.

This is a site away from me, it takes time to get answers.

I used the okidata wiring diagram, tested cables, printers, set inittab.
They have 16 port serial board.  

Only long reports fail after about a page prints when set to 9600 baud.
At 1200 everythings fine, just real slow.

The lines of code worked in the past on this problem.

Thanks,
Gerald
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