{"id":8275,"date":"2026-08-10T16:46:28","date_gmt":"2026-08-10T15:46:28","guid":{"rendered":"https:\/\/www.quantum-bits.org\/?p=8275"},"modified":"2026-08-10T16:54:17","modified_gmt":"2026-08-10T15:54:17","slug":"on-retro-computing-thomson-mo5","status":"publish","type":"post","link":"https:\/\/www.quantum-bits.org\/?p=8275","title":{"rendered":"On retro-computing: Thomson MO5"},"content":{"rendered":"<p>In the <a href=\"https:\/\/www.quantum-bits.org\/?p=8251\" target=\"_blank\" rel=\"noopener\">previous post<\/a>, I <strong>finally<\/strong> took the time to announce the <strong>creation<\/strong> of the <strong>Quantum-Bits Youtube Channel<\/strong>: <a href=\"https:\/\/www.youtube.com\/@quantum-bits-org\" target=\"_blank\" rel=\"noopener\">https:\/\/www.youtube.com\/@quantum-bits-org<\/a>. The first videos, published almost a year ago, were dedicated to my beloved <strong>Amstrad CPC 464<\/strong>.<\/p>\n<p>For the 4th video, I took a step <strong>outside of my comfort zone<\/strong>, and focused on a French 8bit-computer: <strong>the Thomson M05<\/strong> !<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter wp-image-2854\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2022\/01\/quantum-retrocomputing-pixels.jpg\" alt=\"\" width=\"850\" height=\"448\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2022\/01\/quantum-retrocomputing-pixels.jpg 768w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2022\/01\/quantum-retrocomputing-pixels-300x158.jpg 300w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p>As usual, I took a look at <a href=\"https:\/\/www.leboncoin.fr\" target=\"_blank\" rel=\"noopener\">leboncoin.fr<\/a> web site. There, it was <strong>quite easy<\/strong> to find a nice packaged MO5. For a change, the price was <strong>really reasonable<\/strong>! A little over a week later, I received this nice package, <strong>just on time for Christmas<\/strong>. How nice !<\/p>\n<p>The computer and its accessories were still in their<strong> original<\/strong> packaging: &#8220;Tout un monde dans un cadeau&#8221;, which means &#8220;<strong>A whole world in a gift&#8221;<\/strong> in French:<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8280\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-2.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-2.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-2-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p>Inside the box was, of course, the Thomson MO5 computer itself:<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8278\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-1.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-1.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-1-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p>Along with:<\/p>\n<ul>\n<li>Its manuals<\/li>\n<li>A collection of games on cassette tapes<\/li>\n<li>Two joysticks. I could not test them, since I am missing the MO5 joystick module. That been said, It is quite easy to find one (or build \/ order a brand new one). Something for another day.&nbsp;<\/li>\n<li>A couple of software on cartridges<\/li>\n<li>A <a href=\"https:\/\/en.wikipedia.org\/wiki\/Light_pen\" target=\"_blank\" rel=\"noopener\">light pen<\/a>, which, unfortunately I couldn&#8217;t test since I didn&#8217;t have at the time a CRT monitor<\/li>\n<li>A unknown cable (which turned out to be part of the power supply unit)<\/li>\n<li>A cassette tape reader \/ recorder<\/li>\n<\/ul>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8281\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-3.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-3.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-3-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<ul>\n<li>And, finally, a dedicated Power Supply Unit. <span style=\"font-size: revert;\">Unfortunately, after closer inspection, I lost confidence in it:<\/span><\/li>\n<\/ul>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8282\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-4.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-4.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-4-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p>Fortunately, it is quite easy to build a <strong>new PSU<\/strong> for the MO5. I followed the step by step <a href=\"https:\/\/dcmoto.pages-perso.free.fr\/bricolage\/alimentation_mo5\/index.html\" target=\"_blank\" rel=\"noopener\">instructions<\/a> from <strong>Daniel Coulom&#8217;s<\/strong> <a href=\"https:\/\/dcmoto.pages-perso.free.fr\/\" target=\"_blank\" rel=\"noopener\">DCMOTO<\/a> web site (a <strong>fabulous<\/strong> <strong>reference<\/strong> for all Thomson 8bit computers)<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8283\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-5.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-5.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-5-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8284\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-6.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-6.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-6-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p>Once done, I could test the computer, which ran with absolutely no problem. It was quite dirty nevertheless, so, after this first run &#8230; it was time a <strong>good cleaning<\/strong>:<\/p>\n<ul>\n<li>I (carefully) opened the enclosure:<\/li>\n<\/ul>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8285\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-7.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-7.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-7-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<ul>\n<li>From there, I could <strong>take the keyboard apart<\/strong>&nbsp;(be very <strong>careful<\/strong> with the membrane), removed the dust and other messy things, then cleaned each key:<\/li>\n<\/ul>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8286\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-8.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-8.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-8-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8287\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-9.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-9.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-9-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p>Then the <strong>case<\/strong> itself took <strong>a warm soapy bath<\/strong>. Once cleaned and dried, I coated the case with 303 <strong>UV protectant<\/strong>:<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8288\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-10.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-10.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-10-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p>Finally, I took the time to <strong>fully service the dataset<\/strong>:<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8289\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-11.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-11.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-11-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p>Once done, I managed the load software from tapes and from cartridges. <strong>Everything worked !<\/strong> I always amazes me how resilient these old technologies are (when compared to today&#8217;s) !<\/p>\n<p>Then, I decided to take a step (back?) into the present and offer to this little computer a <strong>new device<\/strong>: I ordered from <strong>Daniel Coulon<\/strong> a <a href=\"https:\/\/dcmoto.pages-perso.free.fr\/bricolage\/sddrive\/index.html\" target=\"_blank\" rel=\"noopener\">SDDrive controller<\/a>, which allows to load MO5 software directly from a Micro SD card. It arrived <strong>promptly<\/strong> and <strong>worked like a charm !<\/strong><\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8290\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-12.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-12.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-12-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p>To protect this new device, I designed a <strong>very simple case<\/strong> using <a href=\"https:\/\/en.wikipedia.org\/wiki\/Tinkercad\" target=\"_blank\" rel=\"noopener\">ThinkerCad<\/a>:<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8291\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-13.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-13.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-13-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8292\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-14.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-14.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-14-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p>Then, I exported the corresponding <strong>STL files<\/strong>. Since, at the time, I didn&#8217;t have a <a href=\"https:\/\/en.wikipedia.org\/wiki\/3D_printing#Processes_and_printers\" target=\"_blank\" rel=\"noopener\">3D printer<\/a> (more on that in a later post), I used <a href=\"https:\/\/www.pcbway.com\/rapid-prototyping\/\" target=\"_blank\" rel=\"noopener\">PCBWay 3D printing services<\/a> (no sponsoring there, though &#8211; <strong>full disclosure<\/strong> &#8211; they recently contacted me). I must say that the order and configuration process was <strong>very<\/strong> easy, even for a noob like me when it comes to 3D printing.<\/p>\n<p>Just over a week after, I received this package:<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8293\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-15.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-15.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-15-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p>I must say that the result was <strong>very very good<\/strong> (and I&#8217;m glad the design was right on the first try, since it was my very first attempt at 3D modeling):<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8294\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-16.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-16.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-16-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8295\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-17.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-17.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-17-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-8296\" src=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-18.jpg\" alt=\"\" width=\"850\" height=\"528\" srcset=\"https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-18.jpg 850w, https:\/\/www.quantum-bits.org\/wp-content\/uploads\/2026\/08\/mo5-18-768x477.jpg 768w\" sizes=\"(max-width: 850px) 100vw, 850px\" \/><\/p>\n<p>And &#8230; there we go ! That was a very pleasant journey, and I must say I learned a lot about MO5 \/ Thomson computers. It&#8217;s a shame I had never explored this whole universe before !<\/p>\n<p>Here is the full video (published 11 months ago, sorry for the unfortunate delay) :<\/p>\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"Thomson MO5 restoration and upgrade\" width=\"800\" height=\"450\" src=\"https:\/\/www.youtube.com\/embed\/6Q17MDr02uQ?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n<p>As always, the <strong>retro-community was amazing<\/strong>. A big big <strong>shoutout<\/strong> to <a href=\"https:\/\/dcmoto.pages-perso.free.fr\" target=\"_blank\" rel=\"noopener\">DCMOTO<\/a>, experts like <strong>Daniel Coulom<\/strong>, <strong>Fool-DupleX<\/strong>, and the French <a href=\"https:\/\/forum.system-cfg.com\" target=\"_blank\" rel=\"noopener\">system.cfg<\/a> <strong>forum<\/strong> !&nbsp;<\/p>","protected":false},"excerpt":{"rendered":"<p>In the previous post, I finally took the time to announce the creation of the Quantum-Bits Youtube Channel: https:\/\/www.youtube.com\/@quantum-bits-org. The first videos, published almost a year ago, were dedicated to &#8230;<\/p>\n","protected":false},"author":1,"featured_media":8276,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0},"categories":[23,35],"tags":[],"_links":{"self":[{"href":"https:\/\/www.quantum-bits.org\/index.php?rest_route=\/wp\/v2\/posts\/8275"}],"collection":[{"href":"https:\/\/www.quantum-bits.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.quantum-bits.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.quantum-bits.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.quantum-bits.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8275"}],"version-history":[{"count":18,"href":"https:\/\/www.quantum-bits.org\/index.php?rest_route=\/wp\/v2\/posts\/8275\/revisions"}],"predecessor-version":[{"id":8313,"href":"https:\/\/www.quantum-bits.org\/index.php?rest_route=\/wp\/v2\/posts\/8275\/revisions\/8313"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.quantum-bits.org\/index.php?rest_route=\/wp\/v2\/media\/8276"}],"wp:attachment":[{"href":"https:\/\/www.quantum-bits.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8275"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.quantum-bits.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8275"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.quantum-bits.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8275"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}