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Change 2.11 BSD /dev/console Parameters?

TangentDelta

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Joined
Jan 25, 2015
Messages
41
Hello!

I picked up a PDP-11/73 at VCF-MW this year and installed 2.11 BSD using VTServer. My terminal emulator works fine connected at 9600 8N1, but as soon as init runs /dev/rc a change occurs and I get garbled characters. I can only use the terminal if I change the mode to 7N1.

This shouldn't be much a problem as long as I use 7N1, but I have several devices that are hard-wired at 8N1 that I would like to connect to the system. I can't find any way to change the serial port parameters using getty or stty beyond the "soft" features of the driver. Is there something extremely obvious here that I'm overlooking?

Thanks!
 
Take a look at creating the proper entry in /etc/gettytab to set the desired parameters and edit the console entry in /etc/ttys to use it.
 
So it looks like I can get some semblance of normal output at 8N1 by executing "stty litout". The only problem now seems to be that a carriage-return is not generated with new lines. Minicom lets me add them in, so it shouldn't be an issue for now. Once I get all of the userland files populated I should be able to use getty to set the correct parameters in multi-user mode.
 
I figured it out and forgot to update the thread. Making a note for anyone else that has the same issue.

By default, the system console driver will add a "fake" parity bit to any characters sent out. This is a hard-coded feature of the kernel's console driver and requires modifying the kernel source, and recompiling the kernel, to resolve. I haven't spent enough time poking around in the kernel source to know where this code is at, but it hasn't been too much of a problem now that I have the DHV-11 up and running. If I figure it out, I'll make a note in this thread.
 
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