rlr@utastro.UUCP (Randy Ricklefs) (03/19/90)
We and another NASA contractor are currently working with HP 9000/360
systems, setting them up as a data analysis computers to support real-time
analysis of satellite data. We have run into several problems which hp
response service and the manuals have not solved. Perhaps some reader has
run into and solved these problems.
1) We need to capture ASCII data over a serial port on a 98642a mux at
up to 19.2 KB without loosing characters. We are running X-windows at the
same time. There is significant character loss, especially on the 4 MB
system, when any X windows activity occurs. To limit our losses, a front-end
buffering program is executed with real-time priority 0 and is locked into
memory. X windows is run at real-time priority 10. This has prevented
character loss, but the performance of X and analysis tasks are then
unacceptable. We were hoping an interrupt driven device driver for the
serial port would solve the problem, but we do not know how to write such a
beast and have been warned that doing so could require 6 months, which is more
time than we can afford. We are looking into a serial print buffer as a
better way around this problem, but this is not too elegant! Does anyone have
a better solution?
2) We wish to exchange data with a central location via modems (not the same
port as in 1) above) and have acquired a pair of Racal-Vadic (sp?) 9600 baud
modems to test the setup. The problem is that if one uses cu, kermit
or anything to call out or just talk to the modem (on ttyd01) from the HP,
then subsequent incoming calls are not handled properly. The incoming call
is answered and connected, but there is no login prompt. Turning the modem
off and on does not fix the problem. The only solution seems to be
to reboot! That is not acceptable!
3) Does anyone have an xpr-type program for the HP that will do a dump to
an EPSON FX series serial printer?
Thanks!
--
Randy Ricklefs
uucp: {ut-sally, ut-ngp, noao, charm}!utastro!rlr
arpa: rlr@astro.AS.UTEXAS.EDU phone: (512) 471-1342stroyan@hpfcso.HP.COM (Mike Stroyan) (03/20/90)
> system, when any X windows activity occurs. To limit our losses, a front-end > buffering program is executed with real-time priority 0 and is locked into > memory. X windows is run at real-time priority 10. This has prevented > character loss, but the performance of X and analysis tasks are then > unacceptable. You might get better performance by running the X server at normal priority. The real time priority may have the X server handling client requests in very small groups of requests. There is some amount of fixed overhead in handling a group of requests. If there is a large number of small groups then the total overhead increases. This could give lower throughput than a normal priority server handling larger buffers. > 2) We wish to exchange data with a central location via modems (not the same > port as in 1) above) and have acquired a pair of Racal-Vadic (sp?) 9600 baud > modems to test the setup. The problem is that if one uses cu, kermit > or anything to call out or just talk to the modem (on ttyd01) from the HP, > then subsequent incoming calls are not handled properly. The incoming call > is answered and connected, but there is no login prompt. Turning the modem > Randy Ricklefs Use uugetty on the modem rather than a normal getty. See the uugetty man page and the UUCP tutorial in "HP-UX Concepts and Tutorials" for more information. (I don't actually have to deal with UUCP myself, but this is a problem that I have seen others run into and comment on.) Mike Stroyan, stroyan@hpfcla.hp.com