La magie dans la baraque

In today’s vintage computer post titled the magic in the house, I will share with you about a little French personal computer introduced in June 1984. Thomson Micro-Informatique designed the MO5, and the production of this computer ended in 1986. Before the MO5, Thomson sold the futuristic-looking TO7. Quite logically, the MO5 was followed by the MO6, TO8, TO9, and the TO16, a PC-compatible. Who said that the French are not logical? Ah, by the way, TO stands for Télé/Ordinateur and MO for Micro-Ordinateur. Of course, each one of these models was available in several versions. The MO5 had three hardware designs during its lifetime.

Mine has the second motherboard layout. You can compare it with the press clippings published at launch. Besides, Thomson produced an enhanced MO5E (étendu and export) and a networked MO5NR (nanoréseau) version. Finally, to be a MO5 aficionado, you must know about the Michel Platini version. This special edition has a white livery and wears the signature of the soccer champion. It goes without saying that the Platini is quite rare (I don’t have one). But the Platini is not as unique as the mythical Luis Mariano edition! Did you believe me? I was kidding; there was no Luis Mariano edition. If you didn’t live in France during the ‘80s, there is little chance that you ever played with a MO5, even less you own one today. So, I hope you enjoy the ride.

A few weeks ago, I wrote about the BBC Micro and the InData DAI and mentioned that the Belgian computer – the DAI – didn’t benefit from the support the British Broadcasting Corporation offered to the Beeb. Well, the Thomson personal computers, including the MO5, had better success, as they were boosted by the Le plan informatique pour tous (IPT), an equivalent of the British Computer Literacy Project. Both programs were created to teach young students to use a computer, so they may have a fair chance to land good-paying jobs in the future. The other goal of the programs was, of course, to support the national industry. In other words, eat your dog food kids! ITP trained ~150000 students and ~50000 teachers during its existence. Note that several other state-driven plans preceded ITP in France.

Unfortunately, the MO5 was born outdated. In a quite small package (51 × 291 × 190 mm) and ~1Kg, the MO5 is equipped with a Motorola 6809E microprocessor paced at 1 MHz. It has 48 KB of RAM – only 32 available to the user –, which can be expanded to 96 KB (with a 64 KB RAM module). A version 1.0 Microsoft BASIC was burned in the 16 KB of ROM. Although there is only one cartridge slot available to load software from ROM (Mémo5), the back of the unit gives access to the system bus. In addition, you could buy cassette players and floppy drives. Several kits are available today to connect disk emulators based upon modern hardware.

But in the ‘80s, you often were stuck with the slow and unreliable cassette tapes! The MO5 connects to a TV or a monitor via a SCART connector. I am successfully using the OSSC (Open Source Scan Converter) I covered in a previous post. The MO5 can display texts in 25 lines of 40 characters, and images in 320 × 200 pixels with 16 colors. However, there was a severe color restriction, and you could only use two colors in any given 8 x 1-pixel block. I created a small program to demonstrate this limitation (check out the video).

1 X = 0
2 SCREEN ,6
5 L = 50
10 X1 = RND * 200
20 Y1 = RND * 200
30 X2 = RND * 100
40 Y2 = RND * 100
45 COLOR X,0
16 X = (X + 1) MOD 16
50 LINE (X1,Y1)-(X2,Y2)
60 IF C < L THEN C = C + 1 : GOTO 10
70 SCREEN 0,6

Because the MO5 simply needs a 17 V (750 mA) DC power source, it is simple to pick an AC/DC adapter if you don’t have access to 220 V. Inputs wise, the Thomson has an awful 57-keys AZERTY rubber keyboard (except for the MO5NR model which looks like a MO6 with a mechanical keyboard). On the brighter side, Thomson shipped its computers with an optical pen. This input device is elegant and practical. We can use the light pen in our programs via the INPUT PEN X, Y instruction. When executed, the coordinates of the pixel pointed at by the tip of the pen are stored into the X and Y variables. Then, the code’s execution continues. In other words, it’s a non-blocking read. To measure X and Y, the MO5 uses the video vertical synchronization signal to start a timer and measures the elapsed time between the refresh spot detection by the pen (64000 pixels rendered in 1/25 s, the rest is simple math). Besides this unique capability, the BASIC is standard for the era. Unfortunately for the collecting value, it is not a French BASIC.

Quite naturally, the MO5 was well supported in France. A robust software ecosystem published a few hundred programs and books for the machine. The specialized press welcomed the MO5 with a somewhat positive tone. I attached a few articles from 1984 published by Science & Vie Micro (#6), Votre Ordinateur (#6 and #11), Microtom (#5), L’Ordinateur Individuel (#60), and Micro-Systèmes (#59). If you can read French, take a trip down the memory lane!

More enjoyable to all my readers are the advertisements of the period. Some of them are so anchored into the ‘80s that they are funny! The best one is for the Thomson Users’ Club (Club Micro Thomson).

Overall, MO5 is a great machine to collect. It is a crucial member of the Thomson family, and because of its specificity, it is hard to find outside of France. It has a lot of peripherals, software, and has an active fan base all over the world (ok, in France primarily). So, are you tempted? If you want to play with a MO5 – or any of the non-PC Thomson computers for that matter – I recommend the excellent DCMOTO emulator. You can find it here http://dcmoto.free.fr/index.html , alongside several software packages, and other useful content.

Before concluding today’s post dedicated to the MO5, I owe you an explanation. You may wonder what the heck the magic in the house means? Well, this is the way Marie, a good friend of mine, described the arrival of the MO5 in her home. Let’s do Magic, stay safe, and enjoy Le MO5!