[comp.sys.hp] 2 serial port questions

maswana@aplcomm.jhuapl.edu (Mark A Swana (NCE)) (02/14/90)

1) Are the serial ports on my 9000/835S really able to communicate at 19.2K?
   All efforts to get them to work at this speed (with a number of different
   terminals and pc's) has failed. I'm running hp-ux 3.1; all I should need
   to do is start a getty at 19.2, right?

2) One serial port is connected to a Laserjet (the old kind). Can I get any
   kind of xon/xoff type support? I'd like for print jobs to get queued and
   get a message from lpstat if the printer's not on or out of paper, etc.
   Is this possible?

Thanx for any and all help!

rclark@speclab.bgp-usgs.gov (Roger N. Clark) (02/15/90)

> 1) Are the serial ports on my 9000/835S really able to communicate at 19.2K?

> 2) One serial port is connected to a Laserjet (the old kind). Can I get any
>    kind of xon/xoff type support? I'd like for print jobs to get queued and

I have an 825 and run a laserjet series II at 19.2 K baud with x-on
and x-off.  It works just fine.  On the RS232 port, I run only pins
2, 3, and 7, so I never see things like out of paper reported by
lpstat (actually that would be nice--if someone knows how to do it I'll
make a new cable).  With x-on/x-off, the printer does stop and wait for
new paper to be loaded and doesn't lose anything.  Also, the 19.2 K line
is at least 100 feet long (the printer is on a different floor from the
computer).  The Mux is a standard 6-channel.

dunlap@apl-em.UUCP (John Dunlap) (02/17/90)

>> Are the serial ports on my 9000/835S really able to communicate at 19.2K?
>> Can I get any kind of xon/xoff type support?

We have XON/XOFF trouble with the 6 port mux on the 9000/550.  As I
understand it, this card for the 800 and 500 series is nearly the same.
Upon receipt of an XOFF character, the 6 port mux (27140) takes longer
than the 8 port mux (27130) to stop its output stream.  This has caused
data overflow on some of our terminals (Z-19 with Northwest Digital
graphics boards).  The terminals evidently have almost no buffer space
left when they send the XOFF to the mux.  This problem occurs at 9600
bps with the 6 port mux but not with the 8 port mux.

We also experienced data overruns when connecting a 6 port mux with
an 8 port mux using CU at 19200 bps, but it was OK at 9600.

We have no problem running a LaserWriter NTX-II on an 8 port mux
at 19,200 bps using XON/XOFF flow control.

John Dunlap				Applied Physics Laboratory
hpfcse!hpubvwa!apl-em!dunlap		University of Washington
dunlap@apl-em.apl.washington.edu	1013 NE 40th St
(206) 543-7207 or 543-1300		Seattle WA   98105

jsadler@misty.boeing.com (Jim Sadler) (02/17/90)

/ misty:comp.sys.hp / maswana@aplcomm.jhuapl.edu (Mark A  Swana (NCE)) /  3:39 pm  Feb 13, 1990 /
>1) Are the serial ports on my 9000/835S really able to communicate at 19.2K?
>   All efforts to get them to work at this speed (with a number of different
>   terminals and pc's) has failed. I'm running hp-ux 3.1; all I should need
>   to do is start a getty at 19.2, right?
	The total bps is 58.6K for the mux as a whole.  ie: 3 at 19.2 or 6 at
	9.6 or 2 at 19.2 and 2 at 9.6.
>
>2) One serial port is connected to a Laserjet (the old kind). Can I get any
>   kind of xon/xoff type support? I'd like for print jobs to get queued and
>   get a message from lpstat if the printer's not on or out of paper, etc.
>   Is this possible?

	The queueing should be no problem.  If you haven't setup the spooler
	look in the sysadmin manual page 5-44.  Watch out for step 7 it 
	should read:
nohup sleep 20000000 < /dev/tty0p2 &
stty -parenb -enqak cs8 9600 -cstop -clocal ixon opost onlcr tab3 < /dev/tty0p2

I'm not sure about paper out.
below is my inittab and ll of /dev/lp.

If this help your welcome.
>
>Thanx for any and all help!
>----------


jim sadler
206-234-9009	email	uunet!bcstec!jsadler|root  | hplabs!hpubvwa!b-mrda!jim

init:2:initdefault:
muxi::sysinit:/etc/dasetup   </dev/console >/dev/console 2>&1 # mux init
brc1::bootwait:/etc/bcheckrc </dev/console >/dev/console 2>&1 # fsck, etc.
brc2::bootwait:/etc/brc >/dev/console 2>&1	    # boottime commands
link::wait:/bin/sh -c "rm -f /dev/syscon; \
		       ln /dev/systty /dev/syscon" >/dev/console 2>&1
rc  ::wait:/etc/rc </dev/console >/dev/console 2>&1 # system initialization
powf::powerwait:/etc/powerfail >/dev/console 2>&1   # power fail routines
cons::respawn:/etc/getty console console            # system console
com0:2:respawn:/usr/lib/uucp/uugetty -h hpmodem 2400    #Modem for hp F.E.'s 
#ttp0:2:respawn:/etc/getty -h tty0p0 9600
com1:2:respawn:/usr/lib/uucp/uugetty -r -h -t 60 tty0p1 9600
ttp2:2:off:/etc/getty -h tty0p2 9600
ttp3:2:respawn:/etc/getty -h tty0p3 9600
com4:2:respawn:/usr/lib/uucp/uugetty -r -h -t 60 tty0p4 9600
ttp5:2:respawn:/etc/getty -h tty0p5 9600

crw-rw-rw-   1 lp       daemon     1 0x000002 Feb 16 16:49 /dev/lp

perry@hpfcdc.HP.COM (Perry Scott) (02/23/90)

>We have XON/XOFF trouble with the 6 port mux on the 9000/550.  As I
>understand it, this card for the 800 and 500 series is nearly the same.

True.  Both are CIO MUX cards.  Same firmware.

>Upon receipt of an XOFF character, the 6 port mux (27140) takes longer
>than the 8 port mux (27130) to stop its output stream.  This has caused
>data overflow on some of our terminals (Z-19 with Northwest Digital
>graphics boards).  The terminals evidently have almost no buffer space
>left when they send the XOFF to the mux.  This problem occurs at 9600
>bps with the 6 port mux but not with the 8 port mux.

When DEC first came out with XON/XOFF, they specified that at least 32
bytes of buffer should be available after XOFF is sent.  This has been
widely ignored by the industry.  In fact, the HP RS232 ThinkJet has only
16 bytes left when XOFF is sent, so even HP is guilty.

>We have no problem running a LaserWriter NTX-II on an 8 port mux
>at 19,200 bps using XON/XOFF flow control.

After the ThinkJet flap, we made sure the peripheral divisions clearly
understood XON/XOFF protocol.  :-)

Perry Scott