26 Feb
2013
26 Feb
'13
6 p.m.
On 02/26/2013 05:47 PM, Earl Evans wrote:
Also posted this question in the Vintage Computer
Forums.
OK, I'm stumped. I'd like to use a real VT100 as a terminal with an
emulated PDP-11 running RT11.
When the VT100 is connected to a real PDP-11, it works fine. When connected
to the emulated PDP-11, garbage characters begin to appear on the screen
when, say, doing a DIR command.
The garbage always starts in exactly the same place in the DIR listing.
After that, garbage characters (grey squares) become interspersed with the
good text.
Too high a data rate without flow control. Either enable Xon/Xoff on
both ends or
use hardware control (most PCs do not support that correctly).
If all else fails set the baud rated to something slower till the
problem goes away.
Allison
I have tried this with SIMH under Linux, connecting the VT100 to the serial
console port of the Linux machine. I've also tried it under E11, using that
program's built-in serial terminal capacity. Same exact error in both cases.
I've looked at the RT11 SET command for TT: to see if there are any
applicable parameters. Can't find any. I've set the SIMH TTO device to all
its possible settings: 7B, 7P, 8B, and UC. Same stuff in all cases. I've
looked at the serial settings on the VT100 to ensure 8 bits, no parity, and
correct baud rate. All good.
The VT100 works fine with the Linux box doing Linux-ey things. No character
corruption when doing a big "ls" listing, OK with vi, etc. The SIMH and E11
emulators work fine in their virtual consoles, with no character corruption
when doing a DIR, etc.
Any ideas? I'd really like to, for instance, get my Raspberry Pi to be a
mini PDP-11 system, but I can't get past this character garbage when using
the real VT100. Help appreciated! And thanks for reading!
- Earl