Besides the software (see PsiWin section) you require a cable to physically connect the PC and Psion.

RS232 cablePC Link (RS232)

The Series 5 and 5mx, Revo, Series 7 and NetBook require an RS232 cable (this is the same cable that the Siena and 3c/3mx uses).

If you don't have one, check out the following:

Where to buy

Build your own

  • Psion Link Protocol - here's some stuff about the Psion Link Protocol that, to be honest, is totally beyond me!


Serial Ports

Obviously, you'll need a spare serial port (sometimes called a COM port to plug your PC Link (RS232) cable into.

If your PC doesn't have a serial port then you may be able to add one. This is true only for desktop computers, if you have a laptop skip to the USB Cables section below.

PCI serial port

If you have a spare PCI slot in your PC then you may be able to install a serial port PCI card.

PCI Serial Port

You should be able to pick one up for under £20.

Motherboard header (DB9 - IDC10)

If you don't have any spare PCI slots (newer PCs have fewer PCI slots due to the popularity of the newer PCI Express format) then your motherboard may have an IDC10 connector into which you can plug a serial port backplate.

DB9-IDC10 back plate

This is the option that I went for, as my motherboard (Asus P5N-E SLI) has an IDC10 connector.

If you're going to search the internet for one try searching for:

  • DB9-IDC10
  • DB9 to IDC10
  • serial port back plate

Check your motherboard's manual to see if your motherboard supports a serial port. It may not be mentioned within the text of the manual (mine doesn't) but it should be marked on the motherboard diagram.

If you don't have access to the motherboard manual then check the BIOS as it may have settings for a serial port which would indicate that it supports serial connections.

Failing that get a screwdriver, carefully open up the case and take a look for yourself.

I bought one made by Lindy. It cost me £6.20 and was installed in just a couple of minutes. As it was already enabled and supported by the motherboard I didn't need to install any additional drivers.


I received an email (July 2010) from Ian saying that he'd bought this back plate but had to make some amendments to get it to work on his Asus motherboard. Here's what he wrote:

I bought this product on the recommendation of [your] site for connecting my Psion organiser to an ASUS motherboard.

At the date of writing this (30 July 2010) [your] site [gives] two links to the Lindy product but one is for the crossover version and one for the straight-through version.

I don't think either would have worked with my Asus P7P55D LE motherboard (a current product).

The Lindy product is based on the motherboard connector being wired as follows:


whereas on my MOBO ASUS used:


However the product is well made and easily disassembled so it was easy for me to re-solder 8 connections on the PC back plate.

Note: Initially I thought the problem was due to ordering the cross-over rather than the straight through version. So first off I re-wired the cable as straight through. When that didn't work I searched the web and found from others how the ASUS socket is wired.

I hope that helps someone.

Update 2

I got this email from Roger Watkins, which might help some people:

ASUS COM pin arrangements

I was particularly interested in the copy of Ian's email of July 2010 concerning the pins on his Asus COM port. I traced the cable from the Male COM port on the back of the computer to the motherboard and can confirm that for my ASUS board (an older  PK5 WS ) the pin arrangement are indeed as Ian described. Accordingly I wired up a pin convertor but to my disappointment it didn't work.
Ultimately, the original ASUS COM1 pin arrangement did work on Vista though I am not quite sure why. It may have been setting the bits per second to 9600 (in Device Manager, Psiwin Connections and Psion's remote Link) that did the trick.

After the first connection had worked changing the bps setting back to 115200 and allowing UART FIFO (under advanced section of Device manager) presented no problems and PsiWin 2.3.3 works well under Vista.

(Other contemporary possibilities include a Vista security update to microsoft.NET 3.5 no KB2416473 and the BIOS setup self re-enabling the motherboard's COM 1 port after I had disabled it there and in Device manager). I find it hard to imagine that I didn't fully try the reduction of speed to 9600 at an earlier stage.. I suppose it is always possible that I did but didn't do it simultaneously in all three areas (Device manager, PsiWin Connections and Psion's Remote Link).

PsiWin 2.3.3 only accepts a COM1 port

Unfortunately Psiwin 2.3.3 (running under Vista or XP) doesn't, in its Connection Properties section, remember the changes as to which COM ports to use. It always reverts to COM1 as soon as you OK the window. Thus only a properly installed COM1 will be acceptable to PsiWin. PsiWin however does remember the speed changes. It follows that USB serial cables and a PCI Serial Card would only work if the operating system (Vista or XP) assigned them to COM1. My Advent Notebook (XP) has no built in COM port so Windows assigned the USB -Serial cable to COM1 and Psiwin2.3.3 worked first time 115200 bps!

Again, I hope that helps someone.


USB Cables

Some newer PCs and Laptops do not have a serial port, instead only Universal Serial Bus (USB) ports. In this scenario you will require a USB-to-Serial convertor as well as the standard PC Link (RS232) cable.

In other words you'll need the following chain of connections:

  1. Psion
  2. PC Link (RS232) serial cable
  3. USB-to-Serial adaptor
  4. PC/Laptop USB port

There are a number of manufacturers who can provide the adapter. However ...

Not all cables are created equal!

Be aware that for some reason not all USB to Serial convertor cables appear to work with PsiWin.

And it's not just as simple as finding out which ones work for other users, I've known someone using the same model as mine (Videk) on a Windows XP Professional system (just like mine) and while it worked fine for me, it didn't for him! I've heard similar stories about the Belkin offerings too.

Chipset issue?

I have found this comment from Trygve Henriksen posted to a Psion usergroup helpful:

Many cheap adapters doesn't have all the signals required for PsiWin to be able to establish a link.

If it's any consolation, it probably doesn't work with Palms either...

I generally sort them in two categories, those based on the FTDI chipset, and rubbish...

If by chance, your adapter does have all the pins enabled, you could try to switch off the FIFO buffer on the serial port as this may also cause some problems.

(In Windows XP this can be found within Control Panel > System > Hardware tab > Device Manager > Ports (COM & LPT) > Communications Port (COM n) > Right-click and select "Properties" > Port Settings tab > Advanced ...)


Videk USB to Serial AdaptorVidek USB to Serial Adapter

Videk Online

Videk USB to Serial Adapter (2499G)

I own two of these USB-to-Serial adapters and they have successfully worked with every PC or laptop (mostly Windows XP) that I've tried it with, so it's the only one that I can genuinely recommend.

Windows 7

One adapter that I have says "D400", the other "D700". Only the D700 works with Windows 7 (32-bit). I wish I knew what the D700 designation meant.

I was able to download Windows 7 drivers for the "D700" which state that it is for "PL-2303 Driver Setup Installer, Prolific Edition".


The value for money modem adapter allows a serial device with a 9D output to connect direct to a USB port on a PC. It is supplied with integral flying lead. The unit is supplied complete with a CD for driver installation.


  • Bus powered unit with no power supply required; supplied as a 9D interface with 25D serial connection possible through use of listed 9D/25D adaptor
  • Supports many serial devices (inc 56K modems, PDAs, scanners & digital cameras)
  • Easy installation with automatic handshake mode
  • Compliant to USB 1.1 standards with possible 230 Kbps transfer rate
  • Integral buffer to help upstream and downstream data flow
  • Windows compatible devices - ideal for laptop or mobile users



Videk USB to Serial AdaptorMax Value USB Serial Adaptor

Amazon UK

Max Value USB Serial Adaptor (MV42260)
£8.19 on Amazon UK

I received an email (November 2009) from Dalia saying:

I have used the following USB to serial adaptor on my Psion 5 ... thought you might want to include on your site the link for this adaptor on Amazon to help other users. It's not too difficult [to set up], I had to play around to get it to work, and thought other Psion users might find it helpful.

Quite a few of the reviews on the Amazon UK website agree that this USB to serial adaptor can be used to connect with PsiWin.

(I've not yet heard if it can be used with Microsoft Windows 7, although one reviewer said that it "works with Vista".)


  • Compliant with the USB 1.1 specification.
  • 600 Kbps transfer rate.
  • Plug and play compatibility.
  • USB host device drivers supplied.


KeyspanKeyspan High Speed USB Serial Adapter (USA-19HS)

Keyspan on Amazon USA

US $33.10

Bob Stoner contacted me to say that he had no problems using the Keyspan High Speed USB Serial Adapter (USA-19HS) with his Psion. He wrote:

The installation was faultless and the Psion linked easily to the PC.

I did have to examine the 'key assistant' software which comes with the installation disk to ensure that we had 2-way traffic permitted.

The cost was £19 plus £4.50 postage through eBay UK (from Long Beach California!). This compares favourably with Clove and POS Ltd.


Videk USB to Serial AdaptorEdnet-gmbh

Serial to USB adapter
(Art. Nr. 84204)

I received an email (October 2010) from Zsolt saying:

I bought one EdNet 84204 adaptor and with this my Psion Workabout MX device works well with the supplied profilic driver ... I hope this information can help others.


3Link (image from Gadec)


Series 3 and Series 3a
The Psion Series 3 and Series 3a machines require a 3Link cable which is remarkably different from

You may be able to buy a second-hand one on Ebay - or possibly try POS Ltd.

Note, you cannot make your own as the cable has a special circuit-board (sometime referred to as a 'soap-on-a-rope') between the Psion connector and the Serial connector to the PC.


IR cableInfraRed Link


If your PC has an InfraRed (IrDA) port you may be able to connect your Psion Siena, 3c or 3mx to your PC via InfraRed.

The trick is to tell the Psion to use its IR port like a Serial port. Full details can be found at:

Windows 2000 or XP
If you are using Windows 2000 or XP you will need to make sure that your IR port is using IrDA, and not IRComms; but if you are using Windows XP then you should be using PsiWin 2.3.3! See Pscience5 for more details.

Connection problems?
If you are having real problems connecting to either PsiWin 1.1 or PsiWin 2.x you can test to see whether your Psion and Windows are even communicating at the most basic level by opening up the COMMS application on your Psion and yperTerminal on your PC. More details can be found at Mike McConnell's excellent website under General Info, then click on Comms-Hyper.


You can also connect your EPOC/Symbian machine to your PC via InfraRed.

Martin Guthrie's excellent Pscience 5 website has a number of articles about connecting via InfraRed.


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