I had partial success connecting to cyber1 using my Atari 800 + 850 + The Learning Phone cart (on an Atarimax 8Mbit) + tcper running on a raspberry Pi.
I recently received a cyber1 signon and group and am able to connect to cyber1 successfully using the Linux or Windows PTerm PLATO terminal emulators. Things fall apart for me when on the Atari when, after typing in the group name, you are required to press the SHIFT-STOP key on the PLATO terminal. This key is bound in PTerm as <shift>+<alt>+s or <shift>+<ctrl>+s. On the Atari Learning Phone cart, the key is bound to <shift>+<START>+s. But this doesn't appear to work during my Atari session. One of the other special PLATO terminal keys is the NEXT key. On PTerm it is <alt>+n or <RETURN>. On the Atari it is <START>+n. This *does* work on the Atari. So I'm baffled why I'm unable to successfully send the SHIFT-STOP key sequence. (I'll see if there's a way for me to capture the serial traffic emanating from the Atari).
Attached are some photos.
Note: You can press the <SELECT> key on the Atari to cycle through different background colors. Gray on my Applecolor composite monitor with the front-panel no-chroma button pressed is very readable.
To get this far, I already had a Raspberry Pi (3), 850, some serial cable I made to connect the 850 to a Belkin Serial-to-USB adapter. I use this setup to connect to telnet-enabled BBSs.
1. ssh to the raspberry pi
2. On the pi, I run: tcpser -s 1200 -d /dev/ttyUSB0 -i "&K0" -n5555555=cyberserv.org:8005
3. On the Atari, disconnect any disk drives and ensure the 850 is connected and powered on.
4. On the Atari, boot "The Learning Phone" cartridge. If the R: handler is successfully downloaded from the 850, you should see "1200 baud" message, otherwise it might say "Microbit 300 baud".
6. On the Atari, I need to press <OPTION>+0 (zero) to disable local echo (otherwise double-characters appear).
7. On the Atari, I enter atdt5555555 and press return. (This phone number is registered to the cyber1 server in the tcpser command).
8. A reply from the PLATO service appears: "Press NEXT to begin". Press <START>+n. And so on...
Like I said I can't get the SHIFT-STOP key press to be successfully sent/interpreted/whatever.
Edited by 16kRAM, Sat Feb 3, 2018 9:09 PM.