Garbled text on connect to RPi telnetd server
#1
I had been accessing my Raspberry Pi using my Wimodem232 OLED. The Pi is running telnetd server and I have been successfully connecting to it for several weeks using my Apple II and Wimodem232. 

Today it the connection started acting up. I am able to "dial" into the IP address but upon connection I am getting garbled text like I have the wrong baud rate set but I have confirmed that I do not. 

The Raspberry Pi server remains accessible from my macOS terminal window so I know the server is good. I have factory reset my Wimodem232 using AT&F.
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#2
If you can send/receive commands (like AT&F) then the WiModem232 itself is working. You could always try connecting to a BBS with a terminal program to confirm the over-air part is working.

I have zero experience using a Rapberry Pi, so I have no idea how any of that is suppose to work. I am not sure what you are using the Pi for. You should be connecting the WiModem232 to a router.

Since this all use to work, did you upgrade anything in your system(s) recently - knowingly, or unknowingly?
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#3
(05-13-2023, 06:31 PM)admin Wrote: If you can send/receive commands (like AT&F) then the WiModem232 itself is working.  You could always try connecting to a BBS with a terminal program to confirm the over-air part is working.

I have zero experience using a Rapberry Pi, so I have no idea how any of that is suppose to work.  I am not sure what you are using the Pi for.  You should be connecting the WiModem232 to a router.

Since this all use to work, did you upgrade anything in your system(s) recently - knowingly, or unknowingly?

Thanks for the speedy reply! I think I figured it out. I'm using my RPi as a local telnet server. At first I thought I had damaged my device since I hadn't changed anything in settings, only unplugged and plugged it back in.  Turns out that in order to connect to the telenet server on my Raspberry Pi the AT*T1 command needed to be issued. Perhaps the init string in the terminal software I was using disabled or changed this setting.  All's good in the hood now!
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#4
Ah... yeah, if whatever you are using actually requires "Telnet" mode then this is not an option. Things rarely use Telnet now days because it is much slower than a raw TCP connection.
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#5
(05-14-2023, 02:17 AM)admin Wrote: Ah... yeah, if whatever you are using actually requires "Telnet" mode then this is not an option.  Things rarely use Telnet now days because it is much slower than a raw TCP connection.

What is a raw TCP connection? What unencrypted protocol are BBSes actually using if not telnet?

I'm accessing a raspberry pi that is running telnetd. Is there another option for a server?
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#6
Raw TCP does not use Telnet at all. Telnet is an upper level protocol (that sits on raw TCP) that allows for escaping hundreds of functions. Every time a 0xFF is encountered, the byte following it is checked to see if an escape code is to be used. This means that file transfers are much slower because it's not uncommon for executable files to have 0xFF in them. The escaping was invented in the 1970's (some say 1960's) as a way to query terminals and force certain settings on them.

I am not sure why you would be using a "server" for connecting with the internet. The WiModem simply talks to your wireless router like any other wired or wireless device to connect with the Internet.
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#7
(05-14-2023, 01:11 PM)admin Wrote: Raw TCP does not use Telnet at all.  Telnet is an upper level protocol (that sits on raw TCP) that allows for escaping hundreds of functions.  Every time a 0xFF is encountered, the byte following it is checked to see if an escape code is to be used.  This means that file transfers are much slower because it's not uncommon for executable files to have 0xFF in them.  The escaping was invented in the 1970's (some say 1960's) as a way to query terminals and force certain settings on them.

I am not sure why you would be using a "server" for connecting with the internet.  The WiModem simply talks to your wireless router like any other wired or wireless device to connect with the Internet.

Interesting. So that raw TCP is what most BBS software is using? I just (incorrectly) assumed it was all telnet.

The RaspberryPi is running a telnetd server. I am connecting from my 8-bit computers (Apple II and C64) to the Pi and getting a Linux shell prompt that I can then use to access services that would otherwise be unavailable to me via telnet or BBS connections on the 8-bit machines due to encryption requirements. For example, I have a python script on the Pi that I can run over terminal emulation that gives me ChatGPT access from my C64 keyboard. I can also run Alpine to check email.
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