Vintage Tech: Le Minitel

Minitel is this super fancy terminal introduced in France in the 80's (see the full story). I used Minitel when I was a kid and it crossed my path again recently.

Since it is indeed "just" a terminal, it can be connected to the console of your favourite linux machine, including your Pi. I have a couple Orange Pi myself...

It turned out not to be completely straight forward to connect my Orange Pi One and my Minitel, so I thought I would make a record of the aventure on instructables !

Le Minitel levels can go up to 15v which way too much for an Orange Pi ! A solution is to adapt said signals through a Logic Level Converter.

You want to look for a "Logic Level Converter Bi-Directional Module 5V to 3.3V".

You will also need a "MIDI 5 Pin DIN Cable" to connect to Le Minitel. The Image above shows the 3 pins to need to note: Rx, Tx and GND.

Pictures should be self explanatory.

Keep in mind:

- Tx, Rx and GND from the Minitel connect to the logic level converter.

- Tx, Rx, GND, 3v and 5v from the Orange PI connect to the logic level converter.

- Minitel Rx is connected to Orange Pi Tx on the logic level converter.

- Minitel Tx is connected to Orange Pi Rx on the logic level converter.

I have tried many distro for this project and here is the score: if you want a (working) wifi connection through a usb dongle, settle for Armbian, no more, no less.

You may need to install brew and 7za to unzip .7z archives

/usr/bin/ruby -e "$(curl -fsSL  https://raw.githubusercontent.com/Homebrew/instal...

brew install p7zip

Download image and unzip

wget  <a href="https://dl.armbian.com/orangepione/archive/Armbia...">  https://dl.armbian.com/orangepione/archive/Armbia...>

7za x Downloads/Armbian_5.75_Orangepione_Ubuntu_bionic_next_4.19.20.7z

Identify your usb card (mine is disk1) and burn Armbian image onto it

diskutil list
diskutil unmountDisk /dev/disk1
sudo dd bs=1m if=Armbian_5.75_Orangepione_Ubuntu_bionic_next_4.19.20.img  of=/dev/rdisk1 conv=sync

Insert the sd card into your Orange Pi and connect to it

user: root
password: 1234

tip: change the password to "orangepi"

Your dongle (assuming it is Realtek RTL8188CUS based) should be working out-of-the-box. All you need to do is to launch raspbian-config.

Here is my exact situation:

root@orangepione:~# cat /etc/lsb-release <br>DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=18.04
DISTRIB_CODENAME=bionic
DISTRIB_DESCRIPTION="Ubuntu 18.04.1 LTS"
root@orangepione:~# uname -a
Linux orangepione 4.19.20-sunxi #5.75 SMP Sat Feb 9 19:02:47 CET 2019 armv7l armv7l armv7l GNU/Linux

I enabled uart1 (c.f. pictures):

root@orangepione:~# armbian-config

I changed lib/systemd/system/serial-getty@.service:

#ExecStart=-/sbin/agetty -o '-p -- \\u' --keep-baud 115200,38400,9600 %I $TERM 
ExecStart=-/sbin/agetty -c %i 4800 minitel1b-80

I installed ttyS1 with systemd:

ln -s /etc/systemd/system/serial-getty@.service /etc/systemd/system/getty.target.wants/serial-getty@ttyS1.service
systemctl daemon-reload
systemctl start serial-getty@ttyS1.service

I installed a better version of minitel1b

wget  http://canal.chez.com/mntl.ti
tic mntl.ti -o /etc/terminfo

Switch on Le Minitel, then

- switch Le Minitel to 4800 baud: Fnct+P, then 4

- choose 80-column mode: Fnct+T, then A

- disable echo: Fnct+T, then E

Voila.