In December 2024, I modded a Minitel Telic 1 into an HDMI display and USB keyboard.

Keyboard

The Minitel keyboard is defined by an 8×8 matrix (sadly, it’s a diode-less matrix, meaning ghosting and masking may occur).

Using the following matrix:

↑

Correction

Annulation

↓

Shift

←

→

↲

T

E

R

Y

;

-

:

?

G

D

F

H

*

7

4

1

.

Esc

,

'

Suite

Retour

Envoi

Répétition

B

C

V

N

8

5

2

Guide

Z

A

Sommaire

U

I

O

P

Fnct

S

Q

Ctrl

J

K

L

M

Connexion Fin

X

W

Espace

#

9

6

3

So using an RP2040-Zero board, the KMK firmware and some python:

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import microcontroller.pin as pin
from kmk.kmk_keyboard import KMKKeyboard
from kmk.keys import KC
from kmk.scanners import DiodeOrientation

keyboard = KMKKeyboard()

keyboard.col_pins = (pin.GPIO1, pin.GPIO2, pin.GPIO3, pin.GPIO4, pin.GPIO11, pin.GPIO12, pin.GPIO13, pin.GPIO14)
keyboard.row_pins = (pin.GPIO0, pin.GPIO5, pin.GPIO6, pin.GPIO7, pin.GPIO8, pin.GPIO9, pin.GPIO10, pin.GPIO15)
keyboard.diode_orientation = DiodeOrientation.COL2ROW

keyboard.keymap = [[
    KC.UP,    KC.F24,    KC.F23,   KC.DOWN,  KC.LSHIFT,   KC.LEFT,   KC.RIGHT, KC.ENTER,
    KC.T,     KC.E,      KC.R,     KC.Y,     KC.M,        KC.MINUS,  KC.COLON, KC.QUESTION,
    KC.G,     KC.D,      KC.F,     KC.H,     KC.ASTERISK, KC.N7,     KC.N4,    KC.N1,
    KC.DOT,   KC.ESCAPE, KC.COMMA, KC.QUOTE, KC.F22,      KC.F21,    KC.F20,   KC.F19,
    KC.B,     KC.C,      KC.V,     KC.N,     KC.N0,       KC.N8,     KC.N5,    KC.N2,
    KC.F18,   KC.W,      KC.Q,     KC.F17,   KC.U,        KC.I,      KC.O,     KC.P,
    KC.RALT,  KC.S,      KC.A,     KC.RCTRL, KC.J,        KC.K,      KC.L,     KC.SCOLON,
    KC.F17,   KC.X,      KC.Z,     KC.SPACE, KC.HASH,     KC.N9,     KC.N6,    KC.N3
]]

if __name__ == '__main__':
    keyboard.go()

Display Circuit

Using the circuit following circuit:

Composite Circuit - cfp-radio.com - 2011
Composite Circuit - cfp-radio.com - 2011

I was able to turn a composite signal into one understandable by the Minitel display driver.

Building the Circuit

To build the circuit I made a simple PCB out of the Circuit and Soldered all of the components on it

Unfinished Circuit - 10/12/2024
Unfinished Circuit - 10/12/2024

Adding HDMI

To add HDMI Input I simply used a cheap HDMI to Composite adapter from Amazon and used the RP2040-Zero 5V rail as the power suply.

Conclusion

After a few weeks of troubleshooting I was able to watch movies and play games at a wapping 25 FPS, while having my eyes burned by the cathodic display of this antiquity.

Sources and Inspirations