Path: utzoo!utgpu!watserv1!watmath!att!att!pacbell.com!mips!zaphod.mps.ohio-state.edu!wuarchive!sdd.hp.com!hp-pcd!hpfcso!hpfcdc!perry
From: perry@hpfcdc.HP.COM (Perry Scott)
Newsgroups: comp.sys.hp
Subject: Re: Using the Serial Port
Message-ID: <5570538@hpfcdc.HP.COM>
Date: 19 Nov 90 03:32:01 GMT
References: <10155@helios.TAMU.EDU>
Organization: HP Fort Collins, Co.
Lines: 15

System V defines a default of 300 baud when a tty is opened.  To get
around this, put a "sleep 99999999 </dev/ttyXX &" on the port to keep
it opened, then use "stty 9600".  You may need other stty flags, too.

Be warned that the built-in port on the 300-series is not buffered.  On
the slower machines of the 320-genre, expect to lose inbound data.  The
350/60/70 seem to have enough steam to pull off the 1000+ interrupts per
second that 9600 baud causes.  If you need buffering, the 98642 4-port
MUX works well.

The chip was changed in the newest Apollo/HP merged workstation, which
has 16-byte silos that can be enabled.  By default, though, it is still
unbuffered.

Perry Scott