Quantcast
Channel: terminal – Hackaday
Viewing all articles
Browse latest Browse all 76

Teardown: Alcatel Telic 1 Minitel Terminal

$
0
0

For British teenagers in the 1980s, the delights of 8-bit computers such as the Sinclair Spectrum, Commodore 64, or BBC Micro were firmly restricted to the offline arena. We would read about the BBS scene on the other side of the Atlantic, but without cheap local calls and with a modem costing a small fortune, the chances of us ever experiencing one was zero. When we took the British school rite of passage of a trip to France though, we were astounded to see that every French person was not merely online, but that they were doing so with a neat little all-in-one terminal. We’d just been introduced to the French Minitel system, and in that minute shared a glimpse of the future.

Un Réseau Trés Français

The Minitel terminal is a small CRT monitor with a fold-down alphanumeric keyboard.
My Alcatel Minitel terminal

In the 1970s and 1980s, so-called videotext systems, terminal-based phoneline access to information services on central computers, were seen as an obvious next step for telephone network operators with an interest in profitable new products. In most countries this resulted in services such as the UK’s Prestel, a subscription service relying on costly hardware, but France Télécom instead pursued the bold path of making the terminals free to subscribers with free access to phone listings and yellow pages, but a business model based on pay-to-use premium services.

Thus, through the 1980s all French households had a Minitel terminal beside the phone, and the service became a runaway success. Ever since seeing Minitel terminals as a tourist I’d been fascinated by the service, so here in the 2020s when a friend was visiting their family in France I asked whether he could pick up an old Minitel terminal for me. Thus I found myself parting with around $25 and being rewarded with a slightly battered Minitel cardboard box containing one of the familiar brown Alcatel terminals. I certainly wasn’t expecting one in its original packaging.

On the desk in front of me, it resembles a small CRT TV set, roughly 250 mm x 220 mm x 260 mm. The 9″ monochrome screen is covered by the keyboard, which is released by pressing a button at the top and hinges down in front of the screen. At the back of the unit on one side is a French telephone socket for the conventional phone and mains and phone wall socket cables, while on the other side is a DIN socket for a serial port. The keyboard feels very solid indeed, with a clicky AZERTY layout as well as a numerical pad and a series of call function keys. FInally there’s a power button and a display brightness slider, and when the unit is powered up the letters typed appear on the screen.

Clever Design Makes It A Joy To Dismantle 37 Years Later

Below the CRT is the monitor and PSU board, to the left the terminal electronics.
Below the CRT is the monitor and PSU board, to the left the terminal electronics.

Examining the rear before dismantling the device, it’s clear that there are no screws, instead everything is held together by plastic clips. This makes careful removal of the rear case a straightforward process, revealing the internals. There are two interlocking PCBs, one containing the power supply and the monitor electronics below the tube neck, and the other containing the terminal electronics up the left hand side. A flat flexible cable connects this to the keyboard. Leaving the monitor PCB in place it’s very straightforward indeed to unplug the terminal board for a closer look.

The terminal PCB, with some main chips labelled.
The terminal PCB, with some main chips labelled.

It’s possible to make a serial terminal without any microprocessor in sight, however many later terminals use an 8-bit micro to replace a lot of logic and lend some basic smarts. In this case it’s an 8051, paired with a 6850 UART for serial communication and  the Thomson EF9340 and EF9341 video graphics chipset. These last two chips are an interesting pair, with their own 16-bit data bus requiring 1 K x 16 RAM, and while I’m not sure whether they were specifically designed for Minitel it’s clear that their strengths like more in videotext than in home computers.

All the chips in this unit have date codes from spring 1985, so it likely first saw service later that year. It’s worth noting that an online search reveals versions of this terminal with an entirely different mainboard featuring a different processor and an expansion bus, evidently since the device never ran any user software its internals did not make any difference for the service. The keyboard clips apart to free it from its hinge, revealing a very substantial metal frame surrounding its PCB. This particular terminal has a problem with some of its keys, soon revealed to be due to a failing keyboard cable. I see a couple of adapter PCBs and a more robust modern flat cable in my future.

What Do You Do With An ’80s Dream Here In 2022?

The Jolly Wrencher on a CRT screen
When your hacker friends beat you to it and write the thing you were going to do.

Given the mild annoyance of having to fix my keyboard cable, what can I do with a Minitel terminal here in 2022? The original France Télécom system was shuttered back in 2012, so it’s hardly as though I can dial up to any official services. Fortunately there still exists a lively Minitel hacker scene who program and operate their own services both via the phone for a traditional terminal as online in a web browser. For the minor effort of building a serial cable for that DIN socket I can talk to my terminal from a computer, and among many other options I can use a Python library or an Arduino library to do whatever I want with it. If I can’t be bothered to do any work on it myself, there’s even a Hackaday reader written for me by a friend in a Dutch hackerspace.

With my Minitel terminal carefully reassembled and awaiting such time as I can fix its keyboard cable, I’m sure I’ll find a fun use for it among the plenty of options.

It’s worth signing off with a reminder for anyone tempted to get a Minitel terminal of their own. These terminals were given for free to every French telephone subscriber, and at the height of its popularity every household in France had one. My friend tells me that while a few of the many Minitel models are rare and sought-after, the run-of-the-mill ones like mine are still plentiful enough that any vendor who reads this article and imagines a price hike can be told to take a hike. Find a French friend as I did, and see if they can help you find one.


Viewing all articles
Browse latest Browse all 76

Trending Articles



<script src="https://jsc.adskeeper.com/r/s/rssing.com.1596347.js" async> </script>