[Simh] Extended SimH on BeagleBone controls real blinkenlight panels

[Nathan Cutler]

> 4. then you have your serial device connected over a telnet tunnel to one of
> SimH's user serial ports

This looks great in theory, but breaks down (a little) in practice.
One example: back in the day, I was used to TYPE-ing a long file and
using CTRL-S and CTRL-Q to stop and start the listing. When using the
telnet tunnel, however, for some reason the CTRL-S doesn't make it to
the VAX, so VMS doesn't know about it and merrily goes on sending
data, causing the internal telnet buffer to overflow. As a result,
when I hit CTRL-Q to resume the listing, I've lost data.

(It's been awhile since I researched this, so this description may not
be 100% accurate, but that's essentially what happened. The guys over
on comp.os.vms helped me to troubleshoot the problem, so I refer the
gentle reader to the comp.os.vms archives for more in-depth
information on it.)

There are other glitches using the telnet tunnel as well, all caused
by, well, telnet. Don't get me wrong: it's great that it works at all
and it definitely does provide a good approximation of the experience
of working at a terminal hooked up directly to a VAX, but it's not the
same.