Notes ·
Ian Cortina Put a Real Telnet BBS on a Casio VX-4
Ian Cortina, EI3LH, has built a working telnet BBS hosted on a Casio VX-4 pocket computer.
The VX-4 is an wonderfully constrained machine for the job. Cortina deliberately designed the software to work with the base model's 8 KB of RAM, writing the BBS itself in BASIC.
A Raspberry Pi Zero W provides the network bridge between telnet and the calculator's RS-232 serial port, but Cortina intentionally keeps the actual BBS logic on the Casio. The Pi also keeps an archive of messages so the calculator's tiny storage does not have to preserve everything forever.
And it really behaves like a BBS.
You connect over telnet, enter a callsign, get a menu, read messages, leave a message or disconnect. It runs at 4,800 baud and accepts one caller at a time. Cortina has even demonstrated connecting over a 5G connection rather than his home network.
That is cool for reasons beyond simply getting old hardware onto the Internet.
A BBS is almost the perfect application for a machine like this. Text interfaces need almost nothing. Serial communications were exactly how computers talked to modems. Tiny memory and slow links force the software to remain simple.
It recreates the feeling of early personal networking using hardware that actually belongs to that era.
There is some wonderful nostalgia in connecting a modern phone or computer across today's Internet, through a Raspberry Pi, down a serial cable at 4,800 baud and finally arriving at a BASIC program running on a calculator with 8 KB of RAM.
Cortina is also an amateur radio operator, and he eventually wants to make the BBS available over packet radio. That would make the project even better: old computing, serial communications, radio and BBS culture all meeting in one tiny machine.
Most modern computers could host a BBS without noticing the workload.
Doing it on the Casio is what makes it interesting.
Sometimes limitations are the entire point of the experiment.