Terminal program difficulties

[Dan Moos]

Hope this is a good place to post this.

Using Tera Term as a terminal for a 6502 computer I have running on bread boards.  I have a routine where I can display memory contents in hex. I also display the ASCII value. The issue is, that sometimes I seem to be sending control codes to the terminal program, and all of a sudden Terra Term starts using Cyrillic (I think) characters. I have to reset the terminal to fix it.

Is there some way to make sure Terra Term doesn't react this way? It COULD be an intermittent fault with my UART (I'm probably pushing the limits of what should be done on a breadboard with cheap wires).

I am in the process of slowly moving towards a self sufficient setup that doesn't need the terminal connection for I/O (real close to video, and a PS/2 keyboard interface shouln't be a big deal)

[cv007]

Not much help, but I have recently tried to use tera term for an esp8266 board and had the same problem. I was changing baud rate when booting the board, so would get garbage characters before the baud rate was changed which usually (not always) would cause the problem you described. I have no answer to 'fix' tera term but I just used PuTTY instead and had no problems when running that. I run PuTTY on Windows and Linux, and it works good, but I always struggle with copy/paste in that program (especially on the Linux version).

[Geoff_S]

Do similar errors happen using a different terminal program ?  I've used Putty, TeraTerm and Kermit amongst others, but when debugging serial comms I normally use "Docklight" - not free, but nice because it works well and is very stable, and you can set it up to send or receive specific test strings.

[ChristofferB]

For simple DIY stuff where I don't need alot of features, I much prefer a simpler program like Termite. Debugging hardware and software on a diy computer is hard enough that I don't want to spend 2 hours mucking about only to realize i'd messed up a setting in my terminal emulator. It never hurts to have a few different tools that does the same job!

[hamster_nz]

You most likely  have inadvertantly stumbles over the code sequence to switch characters that can be used to access higher-valued characters when being used on a 7-bit+parity serial connection.

In rough terms, codes less than 28 or code 127 are 'unprintable' (have no associated glyph that can be shown) -  try replacing them with a '?' and see if this stops the strange behaviour.

[westfw]

Set teraterm to 7bits with space parity instead of 8bits with no parity?

[hamster_nz]

Here's something similar to what is going on... an "ESC ( 0" with a short pause will switch to the alternate character set with line draw characters and so on - at least on a Linux console:

Code: [Select]

#include <unistd.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
  printf("This is a test 1\n");

  printf("\033(%c",48);
  usleep(10000);
  printf("This is a test 2\n");

  printf("\033(%c",65);
  usleep(10000);
  printf("This is a test 3\n");
}

Exact results will depend on what character sets your terminal emulator supports.

[lundmar]

From the discussion it seems the OP is running Windows.  However, if you are a Linux user I can recommend to try out tio - a simple terminal I/O application: http://tio.github.io

It's supports direct copy/paste and hexadecimal output mode which comes handy if you need to inspect data received from your microcontroller etc..