Android Hardware Phones Reviews

Gemini PDA review: is the Psion revival worth it? (December 2018 update)

Having written a preview of the Gemini PDA back in February, I initially spent a further week with one of the first production units in April. Now, with the latest iteration of the device in my hand, I’m updating this review (6 December 2018).

As before, this review isn’t a glowing recommendation for a number of reasons, but there are still reasons for people to buy it. And a few reasons not to…

Gemini PDA review: reason to buy #1, the keyboard

The Gemini PDA is a unique device. Nothing like it has existed since the Nokia Communicator and Psion Series 5, back in the days when things were literally black and white. (Okay, black and green.)

Indeed, the keyboard is a close replica of the Series 5’s because Planet Computers, the company behind the Gemini PDA, engaged the services of the man who actually designed the Series 3 and Series 5 for Psion.

Gemini PDA review keyboard
So much of the keyboard is brilliant – what a shame about the unresponsive spacebar

The keyboard is 93% brilliant too. There’s a well-defined action and plenty of travel on the keys, and if you have dextrous fingers and can touch-type you may well soar past 50 words per minute. Perhaps even higher.

Unlike an on-screen keyboard, it’s also easy to type out uncommon words and commands. That could be a huge boon for sysadmins and programmers, or those who work in technical fields.

Commenting on my original preview, Robert Harmsen also made this point: “I have lots of meetings in which I have to make notes. Back in the Psion days, I could type blind and fast on them. And typing on such device during meetings is accepted. Typing on phones is still not.”

It’s also worth mentioning that many, many Gemini users absolutely love the keyboard to the extent that they no longer travel with their laptops. Combined with long battery life, the keyboard makes this a stunningly versatile machine if you can get over its quirks.

Gemini PDA review: reason NOT to buy #1, the keyboard

You’ll notice my cunning use of 93% rather than 100% above. Now, that is an improvement on the April release of the Gemini where I rated it as 90%. As I said then: “that missing 10% proved a royal pain when typing – because really I’m talking about the spacebar. Sometimes it    leaves too big    a space between words andatothertimes itleaves nospace atall.”

I can recognise a change since April. The spacebar isn’t as susceptible to double hits, and while I’d say it missed my press about one time in ten that’s a big improvement and I didn’t get too annoyed by it.

And, as I said before, some of this may be due to my typing style. Perhaps I could adjust it so that I hit closer to the middle of the spacebar. Perhaps I’d adjust my typing method over style. Perhaps I’m hoping for too much.

The problem is that I still yearn for the stunning keyboard of the Psion 5mx, and the Gemini’s simply isn’t as good. You can almost feel the springs when you press down, whereas the Psion somehow had a perfect, smooth action. (I know, because I just tried out my broken 5mx to remind myself.)

Gemini PDA review: reason to buy #2, Android

Right now, the Gemini ships with Android 7.1. Overall, that’s a positive, simply due to the strength of Google’s OS and all the apps that it supplies – not least a free version of Microsoft Word and Excel. (An update for Android 8.1 was due earlier this year and remains due; see the “jam tomorrow” section later.)

Gemini PDA review keyboard


Gemini PDA review: reason NOT to buy #2, Android

The problem with Android is that it’s been designed to be used as a phone OS, not a keyboard OS. Simple things like reading a news story become a pain because you’re either holding it in landscape position, and have to awkwardly scroll down every couple of sentences, or holding it in portrait where the keyboard gets in the way.

Gemini PDA review
Here’s a landscape view of a BBC news story – you can’t even start reading the main text before scrolling

Before I switched to the Gemini PDA as my main phone during the testing process, I hadn’t realised quite how important this is to my everyday use of a phone.

This is one of the reasons why I would hesitate to recommend this style of device as a replacement for your phone; many of the Gemini’s biggest fans simply use it as an old-style PDA or mini laptop replacement.

All that said, a lot of people have dumped their phone in favour of the Gemini. They may well be even more tempted by the Cosmo Communicator, which Planet Computers recently raised over £700,000 for on Indiegogo.

Gemini PDA review: a brief word on Linux and Sailfish OS

After a lot of development work, mainly by the Debian and Gemini community, you can now dual boot the device into both Debian and Android. There’s even an early version of Kali Linux to try, and you can also run Sailfish OS on the Gemini if you prefer.

The advantage of Linux over Android is obvious. With support for video outputs, and all the sheer power of a full desktop OS, this truly does become a pocket computer. Plug in a monitor, keyboard and mouse, and nothing is missing.

Except that this assumes everything works perfectly, which it doesn’t. Numerous Gemini users report problems running Debian, despite the fact it’s now been out for six months; you would hope most major bugs had been sorted by now. For instance, there’s no guarantee that plugging in a USB-C monitor will actually work.

Which leads me to…

Gemini PDA review: reason to buy (and NOT to buy) #3, jam tomorrow

I have nothing but admiration for the team that made the Gemini PDA happen. In the space of a few months, it’s not only been able to develop its own hardware but create an add-on camera, customise Android to work better with a keyboard, and continues to work hard on numerous other enhancements.

That fact that Planet Computers only has a team of around ten people makes this all the more commendable.

Especially because what that team does is often brilliant. Like the Gemini Agenda app, which gives you everything from a daily view to a full-year view of your diary. (Psion fans will also appreciate the basic database app.)

Gemini PDA review ports
Note that the screen is 5.99in, not 5.7in as stated above…

The problem is that, despite being a year old, the Gemini still doesn’t feel quite finished. In fairness, every product is buggy (exploding Galaxy Notes, anyone?), and there’s nothing drastically wrong here, but those issues with Linux and the not-quite-right-keyboard make this feel like v0.95 rather than the v1.3 I’d hoped for by now.

And with the Cosmo Communicator on the horizon, I don’t imagine that the Gemini will be the team’s top focus from this point on.

Gemini PDA review: What about making calls?

Gemini PDA review
The Gemini measures 14.2mm thick and weighs 304g according to our own measurements

There’s no external screen on the Gemini PDA, so how do you know who’s making a call? Through the magic of five LEDs.

This relies on you using an app called LEDison, which allows you to configure sequences of LED flashes or use one of the preset sequences. You can then assign that sequence to people in your address book, or to groups of people. Not quite as convenient as an external screen, which is coming with the Cosmo Communicator, but useful.

Alternatively, you can press the silver Voice Assist button to accept the call and hope it isn’t the bailiff. The Gemini is clever enough to work out which mic/speaker should act as the microphone or speaker depending on how you’re holding it, and the quality of calls is fine.

It’s also surprisingly slim, especially if you once used a Nokia Communicator. The Planet Computers website describes it as 15.1mm thick but I think that must be for an earlier model, because my callipers measured it at 14.2mm. Likewise you should ignore the site when it says 320g (or indeed 400g on some spec listings). It’s actually 304g.

All of that means it’s still twice as heavy and 50% thicker than a normal phone, but you can stick the Gemini into a jeans or jacket pocket without feeling uncomfortable.

The Gemini now supports eSIM technology too. The main benefit? If you travel a lot, you don’t need to swap SIMs each time you land in a different country

Gemini PDA review: reason NOT to buy #4, the price

Gemini PDA review
The box includes a handy Getting Started guide, a charger and the Gemini PDA – but nothing else

With a ten-core MediaTek Helio X27 processor, 4GB of RAM, 64GB of storage and a 2,160×1,080, 5.99in screen, you essentially have a low-to-mid-range phone/phablet. One that would cost you at most £200.

All those components are fine, and I’m more than happy with the quality of the screen having tested it with a coloromiter, but at £599 for the 4G Gemini PDA that means you’re paying roughly £400 for the keyboard. Or £300 if you order the Wi-Fi-only version of the Gemini PDA for £499.

While I understand that Planet Computers has to make a profit, from a potential buyer’s point of view that feels like too much. At £399 for the Wi-Fi version I might just have been tempted, but that “extra” £100 hurts.

Gemini PDA review: speed, battery life, yada yada

I don’t want to waffle on too much about speed. This phone is snappy in use, which is all that really matters. If you care about such things, it scored 1,728 in Geekbench 4’s single-core test and 4,888 in the multicore test. Both solid, mid-table results.

Likewise it managed 17fps in the off-screen Manhattan test in GFXBench, which means it will just about cope with most modern games.

I also ran a video full-screen (setting the screen to 170 candela, which is roughly halfway up the brightness scale) and it died after 11 hours and 6 minutes. That’s okay, but I hoped for more when Planet Computers makes much of its 4,220mAh battery.

In general use, though, you should be happy with the Gemini’s battery life. Planet Computers claims a two-week standby life, and it certainly holds its charge well. More to the point, it can survive a heavy day’s use without dying.

Gemini PDA review: so should you buy one?

There is a niche market for the Gemini PDA. Many of its backers are delighted with their devices, no doubt helped by the fact they paid $399 rather than the full whack. And I can see it for people who use a keyboard for entering large amounts of text or need to enter data in spreadsheets – or people like Martin, who I quoted above, who intends to use his Gemini to take notes in meetings.

He also points out that you’ll be able to make presentations from the Gemini, thanks to the USB-C outputs, and make Skype calls; I should mention that the Gemini includes a pair of stereo speakers but they’re a bit harsh, so it’s a good thing that it also includes a 3.5mm jack.

Even then, it feels like most people would be better served with, say, an iPad mini and a Bluetooth keyboard. 

You really do need to be someone who has a specific need to travel light – or has a nostalgic devotion to the Psion Series 5.

Gemini PDA review
There are two USB-C ports on either side, so you can add a keyboard, mouse and even a monitor

I think you also need to be an optimist. You have to believe that Planet Computers will continue to develop the software and add-ons to make this a device that benefits from constant upgrades.

In its defence, Planet has delivered on most of its promises. Often much later than promised – we’re still waiting for Android 8.1 to arrive – but they have come. 

If you do decide to buy, or already have, then I’d love to hear about your experiences. Do you love your Gemini PDA? Can you type at 120wpm with nary an error? Let me know below.

Links to buy: £499 Wi-Fi-only Gemini PDA | £599 4G & Wi-Fi Gemini PDA

READ THIS NEXT: Gboard review: Is this best Android keyboard of 2018?

Gemini PDA verdict
  • Features & design
  • Keyboard quality
  • Value for money


A solid first effort at updating the Psion Series 5 for the modern world, but some finessing remains to be done

About the author

Tim Danton

Tim Danton is editor-in-chief of PC Pro magazine and has written about technology since 1999. He enjoys playing with gadgets, playing with words and playing tennis. Email


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