Turn one PC into two for free

How do you like the sound of taking one machine and having two people logged into it simultaneously? Sounds pretty neat to me – and it’s free too which is always a tick in the right box.

Canadian company Userful markets Linux-based desktop multiplier and public access computing solutions – effectively turning one system into an X Window server supporting up to ten terminals. They’re giving away a free 2-user copy of their PC Multiplier software which lets you have two people simultaneously connected to a single system but running separate sessions.

Linux for the desktop has a long-established reputation for providing flexible solutions and breathing new life into older hardware and PC Multiplier is no exception. It leverages off basic dual-head GPU technology and USB inputs to turn a monitor keyboard and mouse into a complete workstation. The user has a range of environments to work in all of which are fully customisable.

PC Multiplier comes as a set of installable packages for Linux or as a LiveCD for non-Linux systems. It works with most graphics cards supported by X.Org/XFree86 and has been tested on most major distros running the 2.6 kernel like Fedora Core SLED SuSE Mandriva and Ubuntu (just to name a few).

However the officially supported list of graphics cards is surprisingly limited and doesn’t include any of the more recent graphics chipsets from AMD NVIDIA or Matrox and you’re still required to install proprietary graphics drivers for proper dualhead support.

For those of you who can’t be bothered running up Linux to test PC Multiplier there’s a LiveCD available. Like all LiveCDs it doesn’t make any changes to the underlying system and once it’s up and running individual session performance is pretty good so it’s suitable for either testing or in a limited production environment.

For people with advanced networking skills you could set the LiveCD up to boot from the network allowing you to distribute it across multiple areas without relying on CD media although at a hefty 640MB it’s potentially not something you want streaming out across the wire.

The main difference with running the LiveCD is that the session environments aren’t configurable and you have to take what you get. Having said that the operating environment is pretty comprehensive with productivity communications and media applications available. PC Multiplier supports multi-user sound so each session has its own input and output audio channels.

If you’re a Linux enthusiast and are happy to install the packages every aspect of the session environments can be altered including applications as well as look and feel.

LiveCD – everything in one easy package

PC Multiplier can support up to ten such terminal sessions but then you need five dual head cards all the supporting hardware and relevant licensing from Userful. You can in theory use mismatched graphics hardware but there are limits to the configurations which will work. Additionally there are very few standard hardware platforms which will support so many GPUs so if you’re really interested in such a setup you’re better off investigating a dedicated hardware platform like the Userful Appliance.

More screens than you can poke a stick at…

Actual system requirements are pretty low. For the installed packages on top of the base resources needed to run the host operating system PC Multiplier needs a supported dualhead graphics card 192MB of system memory for a two-user environment (256MB recommended) and an additional 64MB for each extra supported workstation. It has a tiny hard drive footprint of around 13MB and runs on a 400MHz or better CPU. The LiveCD just has the CPU and memory requirements and can even be run on a system with no physical hard drive.

Within their sessions users don’t have access to the underlying file system which means that they have to store data on the network or on USB devices. It’s recommended to link the USB keyboard and mouse for each session to a powered USB hub – this reduces the number of USB ports needed on the host system but also allows each user to connect a USB storage device which is secured to that session alone.

In summary PC Multiplier is a very clever example of what can be done in the realm of public access computing. The free two user product is a great tool for home users wanting to set up secured environments for kids or for desktop admins wanting to demonstrate the benefits of restricted configurable user sessions.