Psion MC 400 Communications

I’m still enjoying playing with my Psion MC 400.  I wanted to find a reliable way of getting data into and out of the machine.  I believe there was a portable FDD available which I would absolutely love to get hold of but I think the chances of finding one of those are very slim.  As far as I’m aware there is no way of reading and writing to the SSDs in anything other than a Psion unit.

Psion Series 3/3A Serial Cable

My attention therefore turned to the RS232 interface.  I was somewhat concerned when I first noticed that the Psion employed a 9 Pin mini DIN connection for the Rs232 port, this connector in the same configuration is found on the Epson PX16 and I’ve never managed to build a working cable for it.

However I discovered on this site that the serial cable that Psion sold for the Series 3/3A is compatible.  The cable comes in two parts, a pod with hardwired cable with a special connector for the Series 3 and a second cable with a DB9 serial connector at one end and the required mini DIN at the other end which plugs into the pod.  This second part of the cable is exactly what you need for serial transfers to and from the MC 400.

9 Pin Mini DIN

Psion link software is built into the MC 400 but I needed to download PsiWin for the PC end.  I found various versions here and downloaded both version 1.1 and 2.3.3.  I installed the former on my Windows 98 Wyse terminal and the latter on Windows XP running under Parallels on my Mac Pro.

After ensuring the Com port settings on the Win 98 box were correct and connecting up the cable I launched the Link application on the Psion and then PsiWin on the PC.  The link was immediately established and I was soon able to drag and drop files between the machines.  I was very impressed with the PsiWin software.

MC 400 RS 232 Port

Then using a USB to Serial converter cable I hooked the Psion up to my Mac Pro and launched PsiWin 2.3.3 under XP.  Much to my surprise this also worked well.  The only issue I have is that the PsiWin software is designed to convert the Psion format files to Windows friendly ones during the transfer process, however neither version of PsiWin seems to understand the files produced by the MC 400 and conversion therefore fails.

PsiWin 2.3.3

One other thing I wanted to try was to connect to my BBS using the built in Terminal application.  Using a null modem adapter I was able to connect the Psion serial cable to my US Robotics modem.  Modem options including Baud rate, frequency, pulse/tone dialling etc can be set within the terminal application.  After a few aborted attempts I found the correct settings and successfully connected to my BBS.  I made a short video of the process and another quick video of general MC 400 operations:-

Psion MC 400 Mobile Computer

Psion MC 400

Probably in my top five of most wanted retro machines I’ve finally acquired a Psion MC 400 mobile computer.  Originally released back in 1989 this ill-fated machine, described by Time Magazine in their All Time 100 Gadgets as one of five gadgets ahead of their time, was initially priced in the UK at £845.00 and according to some sources sold less than a thousand units.

MC 400 Touchpad

Psion MC 400 Touchpad

It is therefore unsurprisingly quite rare.  Way ahead of its time it featured the first touchpad, removable storage in the form of sold state disks (SSDs) and a claimed battery life from 8 AA alkaline batteries of 60 hours.

Lack of compatibility, proprietory interfaces and a high price no doubt all contributed to its lack of success but you have to admire the manner in which its designers and engineers pushed the boundaries to create a gorgeous product that is reminiscent of what Apple do so well.

Parallel & Serial Port Module

The Psion is powered by an Intel 80C86 processor and has 256 Kb of memory.  For external connectivity there’s a standard parallel port, a 9 pin mini DIN RS232 port and Psion’s fast serial link, a precursor if you like to USB.  The parallel and RS232 ports are contained within a removable module that slides into one of the two identical sockets found on the rear of the machine.  Other modules including a modem were available, my MC 400 has a dummy module in the second socket.

Socket & SSD

There are four sockets for SSDs, two on either side of the machine and these are compatible with the SSDs used in the Series 3.  The touchpad mimics the screen, so the position of your finger on the pad will correspond with the cursor position on the screen and the whole pad is clickable.  In practise it doesn’t work particularly well, needing a lot more pressure to move the cursor than we’ve grown accustomed to with modern machines and accuracy is poor.  Fortunately, navigating the GUI with the keyboard is pretty efficient once you’ve learnt the required key combinations.

LCD Display

The screen is a non-backlit retardation film LCD with a 640 x 400 resolution.  It’s crisp but needs careful positioning of lighting for optimal viewing.  The contrast can be adjusted by way of a dedicated function key found to the right side of the touchpad.

The MC400 runs the Psion developed EPOC graphical operating system, a preemptive multitasking OS which would in later years evolve into the Symbian OS adopted by Nokia for its early smartphones.

Battery Module

A suite of software applications are supplied on SSD, a text editor, diary, personal database, calculator, file manager, terminal emulator and word processor.  Not a great deal of other software was available as far as I can tell although my MC 400 did come with an additional spreadsheet on SSD.

Solid State Disks

There were two NiCad battery packs available or you can use 8 standard AA type alkaline batteries which reportedly give an extraordinary 60 hours plus of usage.  I’m currently using rechargeable Duracell AA’s and will be interested to see how long they last.

The included Link software can be used in conjunction with Psion’s PsiWin software (available here) and a suitable cable to transfer data backwards and forwards between the Psion and a PC via the RS232 interface.  I was concerned it would be difficult to locate or build a suitable cable for the non-standard 9 pin mini DIN but discovered here that you can use a Series S3/S3A’s lead.

Rear View

I plan therefore to acquire one of these cables and see if I can get PsiWin working and also if I can hook up a modem.  I’m also going to look at doing some programming with OPL, Psion’s structured programming language.

Some useful resources:-

Excellent MC 400 info and screenshots

More general information

Another good MC 400 resource

Useful hints and tips.