Virtual desktop firm Pano Logic has taken the unusual step of publishing specifications for its Zero Client, to prove that this endpoint device really does not hold or process any data at all, but functions merely as a console for a desktop session running in a datacentre.

Unlike a thin client or PC, the Pano device has no CPU, memory or storage and therefore no on-board software that may need patching or updating. It also means there is no operating system that might incur licence fees.

At the heart of the Pano device is a field programmable gate array (FPGA), which is basically just a custom chip that performs the same actions as the software in a thin client terminal, but using hardwired logic instead.

This Zero Client FPGA links to a standard Ethernet NIC for its network connection to the host system, and also to separate subsystems that provide the display, audio and USB port functions.

These components are all that is required to receive and display screen information from the remote host, and send keystrokes and mouse updates back to it, and the entire thing consumes less than 5W of power, according to the firm.

Pano Logic's architecture reference document reveals that the FPGA logic is divided up internally with a central Pano Direct Protocol Engine talking to an Ethernet MAC that handles the network processing, plus a frame buffer and codecs for the display and audio.

The USB subsystem supports up to four USB ports and effectively just functions as a conduit linking these back to the host, so that USB peripherals can be handled by standard drivers on the user's virtual desktop machine.

For those interested, the Zero Client Reference Architecture can be viewed here, but does not actually go into a great deal of depth for those who know their technical stuff.

25 Feb 2010