[Simh] SimH + real terminal

[Nathan Cutler]

Thanks, Dave.

The terminal is connected to a Linux box and set up as a serial
console. The flow control setting on the Linux serial console *and*
the terminal is XON/XOFF. As long as I stay on Linux, everything is
fine.

The problem begins when, from the Linux serial console session which
is running fine at 38400 baud with no flow control issues whatsoever,
I telnet to SimH/VAX OpenVMS. At this point, the flow control problem
manifests itself. As long as the telnet session lasts, the problem
remains. When I $ LOGOUT and return to the Linux serial console
session, the problem disappears.

Thanks to Jason's suggestion, I discovered that the VAX is somehow
hardwired to expect the telnet session to run at 9600 baud. When I set
the Linux serial console and terminal to 9600 baud, 8N1, XON/XOFF,
everything works fine, both on Linux *and* when I telnet to the VAX.

Nathan


On Tue, Oct 19, 2010 at 9:15 PM, Hittner, David T (IS)
<david.hittner at ngc.com> wrote:
> You have a flow control problem.
>
>
>
> Check your terminal and terminal line to see what the flow control is.
>
> It can be hardware (DTR/DSR) flow control between the real hardware, but
> probably also needs to support software (XON/XOFF) between the simulated VAX
> and terminal.
>
>
>
> Dave
>
>
>
> From: simh-bounces at trailing-edge.com [mailto:simh-bounces at trailing-edge.com]
> On Behalf Of Nathan Cutler
> Sent: Tuesday, October 19, 2010 11:58 AM
> To: simh at trailing-edge.com
> Subject: EXTERNAL:[Simh] SimH + real terminal
>
>
>
> I just got my hands on a "real" text terminal (the kind with the amber CRT
> display). It's a CADO Systems C332 (emulates various VT models).
>
> I connected the terminal to my Linux box's serial port and started a Linux
> serial console on it. I have the terminal working flawlessly with Linux. (I
> can use "vi" etc. on the Linux box.)
>
> However, when I take this a step further, and telnet into the SimH/VAX, a
> problem appears. When the VAX sends just a few characters of output,
> everything is fine. But when it sends a bunch of characters at once (e.g.
> when I do $ DIR, or $ TYPE <long file>), I get the first couple lines OK but
> then it just breaks up into nonsense.
>
> Changing the terminal speed and parity settings makes no difference. (But
> these have no meaning for a telnet session anyway, right?)
>
> Thanks in advance for any help in getting to the bottom of this.
>
> Please note: telnet sessions to the VAX originating from the Linux console
> or X session work just fine. This problem *only* occurs when I (1) log on to
> the Linux box from the serial terminal and then (2) telnet to the VAX.
>
> Any ideas will be greatly appreciated.
>
> Nathan