The IP Box 250S, from Slovakian satellite wholesaler AB-Com, joins the growing band of set-top boxes to adopt the open-source Linux operating system - as opposed to proprietary internal operating software ('firmware').

The main advantage of opting for Linux (and its cute puffin logo) is that you're no longer restricted to the manufacturer for the firmware updates that fix bugs or add new features. Enthusiasts with knowledge of the product's hardware design and limitations obtain the source code and modify or rewrite it to reflect their needs. These, more often than not, coincide with the 'wish-lists' of other users.

As with most Linux-based boxes, it's a PVR design - our review sample was equipped with an 80GB ATA/IDE hard drive, but we've seen 400GB models for sale (it is, by the way, easy to install and initialise a bigger drive should you outgrow an 80GB model).

Which brings us to a major advantage that the IP Box 250S has over the competition - price. The 80GB version sells for around £160 - which takes it close to the asking price of an ordinary budget satellite PVR. But there are caveats.

Most obviously, the IP Box 250S only incorporates a single tuner, so recording one channel while watching another is strictly forbidden (sadly, even if they're on the same transponder). As a single-tuner design, the 250S is equipped with only one LNB input, which is combined with a loopthrough output for driving slave receivers.

There are Scarts for TV (RGB/component/S-video/composite) and VCR (composite-only), plus phono sockets for stereo audio and composite video. Digital audio is catered for by an optical TOSlink output. The only other connectors are the all-important Ethernet, and an RS232 port for upgrading firmware the conventional way.

The box itself is mid-sized and of unpretentious design. In addition to a four-digit LED display are a standby button in the shape of a horseshoe and an array of buttons for channel selection, volume and menu access.

There are no pull-down flaps and, as a result, no hidden goodies like a USB port or CI slots. But then again, do you need the latter if your receiver is capable of emulating CAMs anyway? Instead, the 250S gives you a card slot for use with whatever CAM your chosen firmware is emulating, which is arguably more useful.