ssheven VS Zimodem

I believe, there are "modern" ssh clients for legacy OSes. A quick google search gave me this SSH client for Mac OS 7/8/9.

The project is up on GitHub at https://github.com/cy384/ssheven.

Ssheven: A modern SSH client for Mac OS 7-9\ (120 comments)

I had the link tagged in the 2nd photo. But here is the GitHub I followed. There’s also a YouTube guide like thing. https://github.com/bozimmerman/Zimodem https://youtu.be/tYWjaZoEykA

Presumably something like ZiModem : You take a modern microcontroller with WiFi and a UART, and have it pretend to be a Hayes modem to the UART while sending traffic over WiFi. You'll probably also need a 232 level shifter.

As they are both ESP32/8266 based, I would imagine they’ll perform basically the same and probably run ZiModem (https://github.com/bozimmerman/Zimodem) I have a homemade one using a NodeMCU ESP8266 board and a Max3232, running ZiModem. Works great.

If I accepted having an intermediate jump box, then things go even farther down. Any with a telnet client works, and with something like ZiModem that opens up literally anything with a serial port. I've done "real" work from an Atari 8-bit and Commodore 64 by telnetting to a jumpbox and then sshing into my work Macbook. Spending a whole day that way would be pretty challenging but it could be done. Throw in slack-term and I was able to even keep up with company chat. I was only doing it for fun so I didn't go all the way but I could have set up our g-suite in a terminal IMAP client.

Can't use Espressif's AT firmware, but you could modify one of the open source AT-like projects like this https://github.com/bozimmerman/Zimodem to add whatever you wanted there

Yeah, the 95LX is just running the standard 4 pin serial cable that HP provides with the 95LX Connectivity Pack. That goes into a WiFi serial modem I bought from ArcaneBytes which seems to be more or less a clone of all the other ones since it runs ZiModem and doesn't appear to do add anything.