loh@eemips.tamu.edu (Kou-Hung Loh) (11/17/90)
I need someone help me to configure the built-in serial port on a HP9000/300. I am planning to connect a "listen-only" circuit board to this port to receive commands from the workstation. I have implemented this connection on a VECTRA PC by using its COM1 port configfured to: (9600bps, 8bits, 1stop bit, no parity) , and now I like to switch to the workstation. There is one device file called "serial9" addressed to that port in /dev/rmb (major number:1 , minor number:0x090004). But when I cated a text file redirecting to this file, I found nothing happened. I know I may need to use "stty" to set termio, and I just don't know how to do it properly. Any comments/suggestions will be highly appreciated. Lawrence Loh Department of Electrical Engineering Texas A&M University (Voice) (409)845-7486 (Fax) (409)845-7161
perry@hpfcdc.HP.COM (Perry Scott) (11/19/90)
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
jns@hpuerca.HP.COM (Jeff Squires) (11/20/90)
Hi there -- try this: nohup sleep 999999999 < /dev/rmb & stty 9800 cs8 -parenb <other termio(7) stuff as needed> < /dev/rmb stty -a < /dev/rmb /* just to check out what you have set */ now do your cat [file] > /dev/rmb and see if it works Hope this works for you !! Jeff Squires no guarantee given or implied by me or my employer -- just helpful advice