The has a standard Phoenix Award BIOS. Hit the DEL key on power-up to enter the setup screens. It identifies itself as "Phoenix SecureCore Tiano Setup". Mine had no password set. If the default password is set, reflecting its Wyse origins, Fireport should get you in.
With a pen drive inserted in one of the USB ports I found that the Boot screen presented me with:
Boot Priority Order
The VXC-6215 runs SUSE Linux Enterprise.
For updates a Cisco administration document for the VXC-6215 points you to: http://www.cisco.com/cisco/software/navigator.html and then says choose:
Products
-> Voice and Unified Communications
-> IP Telephony
-> Virtualized Endpoints
->Cisco Virtualization Experience Client 6000 Series
-> Cisco Virtualization Experience Client 6215.
At the time of writing (May 2017) this had become:
Products
-> Collaboration Endpoints
-> Virtual Endpoints
->Virtualization Experience Client 6000 Series
-> Virtualization Experience Client 6215.
[November 2019: You get redirected to: https://software.cisco.com/download/home].
Anyway, when you finally reach the end of line, you end up with a pop-up that's starts with those fatal words:
"Log In and Service Contract Required"
John Haywood who was after an updated BIOS pointed out that, as the VXC-6215 is actually a Wyse Z series under the skin, you can actually use the Wyse tools and firmware to update the VXC-6215 and turn it back into a Wyse box.
Note: The Wyse firmware update tools include a number of security mechanisms. I would guess these are primarily there for two reasons: (1) To guard against finger trouble where customers may try and load the incorrect firmware that might brick their hardware. (2) To honour their licensing agreement with Microsoft (or whoever). e.g. A thin client that was supplied running Linux does not have a license to run Microsoft Windows Embedded Standard. Circumventing these controls to load an alternative licensed Operating System that the manufacturer offers is effectively piracy. Of course there is nothing to stop you loading your own licensed copy of an alternative operating system. The ones on the manufacturer's website are there to update already licensed installations, not to upgrade them to a different OS.
What is described here is just an upgrade to the BIOS. I do not know exactly where this sits in the letter of the law - INAL.
Note 2:You will be using Wyse's tool in a way not intended by Wyse. Although John was successful in his endeavours there is always a risk that, as we're dealing the BIOS, that you might 'brick' your thin client.
If you download the firmware file for a Z series thin client from the Wyse website and try and use the Wyse USB Firmware Tool to 'push' the new BIOS onto the VXC-6215 the tool will refuse to do so and stop with an "XXXX" error.
John's approach is to start by using the Wyse USB firmware tool to 'pull' the existing BIOS image from the VXC-6215, which the tool writes to the pen drive. He then overwrote the bios.img file on the pen drive with the one downloaded from Wyse's website. Finally he ran the USB Firmware Tool again but this time selected the option to 'push' the image back on to the VXC-6215.