Retro Writing 08 – Psion 3mx

I have been interested in the Psion family of mobile computers for quite some time already. I even imported the most famous one, the Psion 5mx, all the way from England to test how well it fared as a distraction-free writing device, explore it and write an article about it.

Even though I ended up selling it to another retrocomputing enthusiast, I thought it was an elegant device and started looking for a way to lay my hands on other Psion PDAs. Recently, finally, I was able to buy two units very cheaply — both were in terrible condition and sold as non-working. The predecessor — Psion 3mx, had the screen burned dead-black (something I often face in old devices) and was just full of leaked battery juices (ouch!). The newer Psion — Revo Plus looked better on the outside but would not turn on either. Being OK with just dissecting both devices even if they did not function, I bought both for about 20$.

The Revo Plus was just dead. The rechargeable NiMh battery leaked badly inside its case damaging ribbon cables, circuit boards, and even the plastic beyond repair. The 3mx, however, even though at first glance it looked like a complete goner, turned on when I bypassed the acid-filled battery compartment connecting two AAs straight to its motherboard. Now that I knew it was working, I could repair it by replacing the burnt LCD film and recreating the rotten-away battery contacts. It took some work, but now the device is functional again. Even though the battery compartment is held together with copious amounts of super-glue and best wishes, I can at least try the PDA out and write an article about it!

The hardware:

The Psion 3mx was the last upgrade in the popular 16-bit (SIBO) Series 3 line, and it was released in 1998 after the famous series 5 was already on the market. Just the last upgrade to the older line before it was discontinued. The PDA sported a 16 bit NEC V30MX processor running at 27.684 MHz and 1 or 2MB of internal storage — I was lucky to get the most awesome 2MB one!

As expected from the Psion company, the design is quite appealing and elegant — the case has a lot of pleasant curves and indentations, feels great in hand, and looks modern when placed on a desk. The device feels light even with two batteries in, but also sturdy enough (even my battered one). When opened, the battery compartment stands out at an angle, creating a kind of base that props the whole PDA up a bit. This action also reveals a strip of touch-sensitive shortcut buttons below the main screen.

The LCD panel is similarly sized to most devices of that period (HP 200LX or the Cassiopeia) is not touch-enabled but backlit. Below the screen, we get a full keyboard with separate plastic round keys. On the back of the device, there is a speaker and two ports for expansion cards (memory expansion or software cards were available). One of these also hides the backup battery slot. We also get an IR blaster on the battery leg part, an RS232 port on the side (and an external power supply port too). Interestingly, there is also a microphone for taking voice memos on the go.

Overall, the 3mx is a well-rounded device (pun intended), and I like its look and feel a lot.

Let’s get to the writing!


Because the screen is not touch-enabled, it’s brighter and easier to read than some other devices from that period (cough, the HP 360LX cough). It’s still not as good as the NEC ARDATA word processor, which still wins by a long mile in screen size and contrast despite being made in 1997, but it’s good enough and probably was a bit better when new. The screen is also backlit to use the PDA in dark places in a pinch.


I was apprehensive about the typing experience: the keyboard looks uncomfortable with its flimsy plastic calculator-type keys. After giving it a try, though, I can say that it’s actually not unpleasant to type on. Yes, the keys feel gummy and there’s no firm click from them. But the plastic keys are nicely profiled and well-spaced. An audio “click” is also coming from the PDA’s speaker that tells us when a key was pressed. Practicing a bit, one could type quite fast on this small device. The angle from the battery compartment stand also helps a little to make typing more comfortable.

The touch-strip allows for quick switching between applications – it’s quite useful even though it has to be pressed a bit harder than I expected.

Getting things in and out:

The data can be transferred out and into the device through a serial cable or via IRDA to another Psion series 3. Sadly, I don’t have the cable (the plug looks very similar to the PCMCIA card dongle plugs) as my unit did not come with one, and currently, they seem to be available online only at very steep prices (often more than a hundred dollars!). I don’t have any other series 3 units, and the expansion ports also work only with proprietary SSD cards, so there is no CF card swapping with modern devices here. For me, this is probably the biggest minus of the device. The internal 2MB of the 3mx model is more than enough for writing a blog article or two or even a few chapters of a novel, but currently, I have no way of getting any data out of the device.

The software:

Like on the Psion 5mx, the operating system is nice and snappy. It also looks better than the DOS-based one of the HP200lx. What surprised me the most, though, was the built-in writing software — the Word and Spell apps are just great.

To be honest, I think that the Word text processing app would be a great rich-text editor to have even on modern computers or tablets. It’s very intuitive and has some innovative features that I have not seen anywhere else! It seems to me that Psion was quite serious about innovating in the field of text processor applications making writing stylized text simple and efficient.

The Word app has most of the basic requirements covered — one can not only save and open files but also save documents as templates, revert files to saved versions or merge files together. The Edit menu offers standard Copy and Paste functionality but also allows, for example, to Evaluate text (solve simple inline mathematical equations right in the document!). There is the simple Search and Replace, Wordcount capability, Pagination, and Print with Print Preview. Thanks to the featured Spell app, we can also use Spell Check and Thesaurus options right within the text editor — both work quite fast and efficiently.

Very well done so far indeed, but the most interesting part begins when we explore the text formatting options. This is a rich-text editing app (we can even save files as RTFs), so we get paragraph and character styles such as fonts, font size, underline, bold, italics and text-align. But it’s interesting how exactly we can apply these: we get Styles (paragraph styles) and Emphasis (inline text styles) that we can use, edit and define.

Each of these styles has a two-letter code, for example, ‘NN’ for normal text, ‘HA’ for Headline style A, ‘BL’ for Bullet List, and so on. We can apply these styles using the menu or by pressing CONTROL and the code, so CTRL+H and A gives us a headline. This method works for whole paragraphs or just words inside the text — we can press CTRL+B, B for bold text and then return to the normal font by CTRL+N, N — this is awesome — so flexible and intuitive! Especially that we can display the paragraph codes on the left side of the text so we can see what paragraph is in what style — and all the styles, fonts, etc. are displayed on the screen while we write in a proper WYSIWYG way.

This is not as obvious as it would seem currently — with DOS-based editors, like Word, for example, even in the graphic mode, one would only get things like bold font or italics displayed on the screen, and the rest of text styles — different fonts, font sizes, etc. would be only visible when the document was printed.

Anyway, I would like to see an RTF editor with this method of user-definable two-letter shortcuts on a modern system, but maybe Psion patented this solution.

The cherry on the top with the Psion’s editor is that it offers four zoom modes with word wrap while still displaying all the fonts and styles, and it has an outline mode based on the headlines inside the text!

The stand-alone Spell app is a very simple thing, but it’s great to see a whole spell-check and thesaurus database already present on a device that only has 2MB of space for the user. We can input a word to check the spelling or press the TAB button for a quite extensive thesaurus entry.

Other than the two apps I wrote about here, there are a few more productivity and PIM applications on the device. I’ll only mention that the Files app is quite well designed with an efficient two-window interface for moving things around.

The downsides:

Apart from how difficult it is to get data off and onto the device if one does not have the serial cable, I like this PDA a lot. It’s fast and sleek and has this Psion “designer-feeling” I appreciate.


Yes, there is a “but,” sadly. I think the Psion 3mx suffers from the same over-engineering problem that plagued the other devices. Even though it feels a bit more solid than the 5mx, about which I wrote earlier, it’s still quite brittle and delicate. The mechanism that props open the battery compartment and flips up the touch-strip, cool as it is, also makes the hinges complicated, small, and brittle. The battery compartment is also made in such a way that the batteries and springs inside push on it from the inside, so the plastic breaks into three pieces near the hinges.

Yes, the HP200lx had its own hinge problems, and the software and hardware feel a bit squarish, slower, and boring, but compared to the Psion, it’s a solid workhorse, even though it was released four years earlier. The 3mx, especially after all these years, again feels like something I would have to “take care of” and not just use and have fun with.

I’m really happy that I managed to resuscitate my dead unit to explore it and learn about it, and I just loved some aspects of it, but I would recommend buying one only for retro-PDA enthusiasts or collectors.

8 thoughts on “Retro Writing 08 – Psion 3mx”

  1. No i pięknie, następny nawrócony ! Mówiłem, że na psionach fajnie się pracuje !!!
    Ja miałem jeszcze większą radość jak znalazłem spolszczenie do systemu i zadziałała konwersja znaków pod windowsem xp.
    Co do Revo – czy można by zobaczyć zdjęcia płyty? Trudno mi uwierzyć że bateria skorodowała płytę główną, skoro one są w doczepianej części ?!
    Czy podłączał Pan zasilanie przez stację dokującą? W moim Revo nic nie chce działać przez wytartą tasiemkę od płyty do dostawki z bateriami i irdą. Gdzieś widziałem zdjęcie tego problemu to podeślę. Pod stacją dokującą się uruchamia, ale to już nie jest sprzęt przenośny i nie zachowuje wpisanego tekstu/aplikacji. W każdym razie proszę jeszcze nie wyrzucać.
    Co do obudów to ludzie zalepiają pęknięcia i używają dalej. Tam chyba materiałem jest ABS to polecono mi ABS cement od Tamiya. Czytałem też o ew. zmniejszaniu naprężenia od sprężynek w zawiasie.
    Dla mnie piorunująca jest natychmiastowa gotowość do pracy i zasilanie na baterie.
    Miłej pracy!


    1. Płyta główna wygląda OK, problem jest z tą małą płytką która jest w tylnej części co odpowiada za ładowanie baterii i podczerwień – została kompletnie zeżarta razem z kablem który idzie do głównej części. Stacji dokującej nie mam więc ciężko mi coś sprawdzić. Potrzebowałbym jeszcze jednego REVO jako dawcy albo przynajmniej konkretnej dokumentacji płyty głównej żeby wiedzieć gdzie się podpiąć z zasilaniem itp. Wyrzucać nie wyrzucam – poluję na “dawcę” szczególnie że wydaje się że ekran jest w miarę OK. 😉 Pozdrawiam 👍


  2. Hi Mat 🙂
    Why are you absent from youtube all that long? Have you lost completely your interest on videos?
    Regarding this PDA… PDAs are very useful devices and I don’t know why they don’t produce them anymore instead of making the all in one tablets that have a trillion functions but lack a keyboard.
    But….you are going to damage your eyes with this particular screen. How the heck can you see anything in this thing? lol


    1. I’m very busy doing art and taking care of our new baby boy 🙂

      And yeah for an hour or two writing session – old PDAs are OK – writing is not what I do all day 😉 Thank you for reading 👍


  3. PDAs! What memories from nineties! I think they got stuck somewhere in my mind, because many years later I experienced the same interest in e-ink devices (like onyx boox, which I use for studying and distraction-free writing with BT keyboard).
    This kind of fascination with stuff is familiar to me. The dreamy projection of how everything would be better (reading, writing, seeing, understanding, thinking) if I just had this or that thing, emerges sometimes. I will not further dissect this feeling and the enthusiasm and nausea that sometimes accompanies it. But I found in it something devoid of negative nuances, just nice: the joy of sharing these little obsessions (that in some moment moved us to imagine and desire and escape) with someone else. A friend obsessed with wearable GPS and GALILEO technology; another focused on small rooms acoustic and DIY digital-analog-converter devices; the shamanic atmosphere surrounding development of 6×6 negatives films stored for years in almost forgotten bulky Japanese copies of even bulkier Swedish cameras. I learnt something new about reality and people and myself too through these objects, even when I don’t remember what object we were discussing about, to realize god-only-know which weird project.
    Your post gave me the opportunity to think about that and I’m glad it happened.
    Congratulations for the newcomer!


    1. Thank you very much. I did not write about this but on one of the devices I bought (NEC ardata) I found some, well, data of a person who was using this in ‘97! Which is surprising considering most of these devices had memory that vanished when the batteries die. We found plans for a photo shoot of a cosmetics line with a model we knew actually listed in the documents 🙂 and on my hp200lx there was a digital map of Ahikabara from the ‘90s too listing all the shops and so on. Cute. I also found some ‘90s porn browsing history on a sharp Zaurus which was not so nice though hahahah


      1. That is a step further and actually quite alike buying old trunks at flea markets and discover old diaries and letters. When writing a diary some of us thinks about the possibility our words will be read from someone else at a certain point…but browsing history ahahahhahahaha.
        The Ahikabara digital map from ’90s is intriguing! Have you tried to follow the route and see if/how places changed?


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