controlling console baud rate and...

controlling console baud rate and...

Post by Chris Hawl » Mon, 29 Nov 1993 07:46:05


        I have two problems, the latter might be in the serial FAQ...

        I can't seem to "stty 2400" a VT... Is this a bug or is it
deliberate?  I'm trying to guage the speed of display over a 2400 baud
modem link on certain display files, etc.  Is there a way I can slow a
VT down to 2400 baud?

        And, I just tried to upload a file using Zmodem, and it just
dumps the whole file to the modem at max speed (19200), when I was not
connected at high speed.  I don't think these are related, but just in
case...  How do I set the flowcontrol on serial devices?  I will read
the Serial FAQ tonight and look for "gettydefs" and "inittab", and see
what I find, but any help would be appreciated.



I knew Everything when I was 19.  Now I hang out with his brother, Jack Shit.
     =========>> Check out the NCF Linux SIG! ( GO LINUX ) <<===========


controlling console baud rate and...

Post by Sunando S » Tue, 30 Nov 1993 04:53:58

Quote:>Finally, the SLS 1.03 /etc/profile sets the TERM variable to console.  Why is
>this?  Shouldn't this be the job of something like /etc/gettytab (gettydefs?)?

I think this is a wrong procedure in SLS.  I had no end of trouble because
of this.  The correct way, I think, is the following:  SLS uses shadow
password, which uses the file /etc/login.defs for setting up defaults for all
login sessions.  You will find a line there which sets up the terminals.  It
looks for a file called /etc/consoles, which should look like this:

        console tty1
        console tty2
        console tty12
        vt100   ttyS1

and so on.  The whole thing is quite clearly explained in /etc/login.defs,
with plenty of comments.

Sunando Sen


controlling console baud rate and...

Post by Christian Schlichther » Wed, 29 Dec 1993 22:52:00

Quote:>Finally, the SLS 1.03 /etc/profile sets the TERM variable to console.  Why is
>this?  Shouldn't this be the job of something like /etc/gettytab (gettydefs?)?

The correct way of doing this is to edit the file /etc/ttys (on BSD
systems) or /etc/ttytab (on SYSV systems). As Linux should one day
become a SVR4, the file should be named /etc/ttytab. You should also
edit the file /etc/login.defs to set this filename. Look at the
comments in /etc/login.defs to see how this is done.

I don't know the format of /etc/ttytab exactly, but it is either this

  console tty1

or vice versa.



1. MVME335 Auxiliary Control Registers, baud rate set 2


     We are running a Motorola 68030-based VME-bus system, and UNIX, System
V, Release 3.

     We have MVME335 Serial and Parallel I/O cards installed.  We want to use
the 38400 BPS rate.  On page 3-18 of the manual that came with these cards,
it says 38400 is possible if ACR(7)=0.  (If ACR(7)=1, then 19200 is the
highest possible rate.)  The driver defaults to ACR(7) being 1, and 19200 is
the highest baud rate by default.  Also, it considers these two different
sets of baud rates, set 1 and set 2.

     I am trying to find out what I change to make bit 7 of the ACR char be
0, and I haven't yet found it...

     In the file /usr/include/sys/m68681.h, I see this:

/* auxiliary control register: ACR operations */
#define BDSET1        0x00        /* baudrate generator set 1 */
#define BDSET2        0x80        /* baudrate generator set 2 */
#define CCLK1        0x60        /* timer clock: external rate */
#define CCLK16        0x30        /* counter clock: x1 clk divided by 16 */

     Okay, so I see the define BDSET1 would clear bit 7 (evidently bit 7
is set by default and we use baudrate generator set 2); I see BDSET2 would
set the 7th bit.

     What I haven't found yet (no examples that I've seen yet, anyway) is
what driver variable do I issue the "| BDSET1" to?  I presume it would
be something in the file /usr/include/sys/mvme331.h, but I haven't yet
figured it out...

     If you can help me figure this out, I'd appreciate it!  If you need any
further information, please just ask!

     Thank you.
Barry L. Bond  (Software Engineer)       | SAIC

72235,1530  (CIS)          <-- personal  | (407) 823-7345, Ext. 549

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