I don't know exactly how many different bits of hardware lurk under the VX0 banner but I have now encountered three. From the front they look identical, but turn them around you have an obvious difference on the back panel (see above).
My take on it is that initially (from 2006) there were the Vx0 models. These have varying amounts of flash and RAM and run either WTOS, Win CE, Linux or Windows XPe. The base hardware was a 1GHz VIA C3 with a CN333, had a standard VGA socket for video, two serial ports, a parallel port and a PCMCIA socket.
In mid 2007 these transitioned to the Vx0L models where the processor changed to a lower power 800MHz VIA C7 with a CN700 or CN800, video output changed to a DVI socket, and one of the serial ports and the PCMCIA port were dropped. Manufacture of these units stopped in 2008.
They were replaced by the Vx0LE models. The one example I have seen is identical to the Vx0L model, but the processor has been upgraded to a 1.2GHz VIA Eden CPU.
I've also come across mention of the V90 Dual Video model (V90DV?) but I don't know whether this different hardware yet again, but I think it may be just a 'Y' cable used with the Vx0L hardware.
Anyway I either have or have seen mention of the following part numbers (not an exhaustive list):
Part no Model Flash RAM EOL 902094-07L V90 512MB 256MB 10/31/07 902094-29L V90 512MB 256MB Internal Smart Card reader 10/31/07 902094-22L V90 512MB 512MB 10/31/07 902094-41L V90 1GB 512MB 10/31/07 902095-02L V30 64MB 128MB 08/07/08 902095-10L V30 64MB 128MB Internal Smart Card reader 08/07/08 902124-01L V90 Dual-Video 512MB 256MB 08/07/08 902124-04L V90 Dual-Video 512MB 512MB 08/07/08 902124-21L V90 Dual-Video 1GB 512MB 08/07/08 902132-02L V10L 128MB 128MB WTOS 08/07/08 902141-14L V90L 512MB 256MB XPe 05/11/10 902141-02L V90L 512MB 512MB XPe 05/11/10 902134-02L V30LE 128MB 256MB CE 5.0 05/11/10 902142-02L V30LE 128MB 512MB CE 5.0 05/11/10 902179-02L V30LE 128MB 512MB CE 6.0 902180-02L V30LE 512MB 512MB XPe
Also of the various Vx0's and Vx0L's I've encountered I have 5 working Vx0Ls, 2 working Vx0s and 4 dead Vx0s. I don't know if there is any significance in that fact but the V90s do seem to have a reliability problem. At least a couple of my dead V90s did work initially and then stopped for no apparent reason.
I found the following information on Wyse's site:
Product Lifecycle Matrix Table for Wyse Thin Clients
Model Part Number EOL Last Build Version V10L 902132-xxL (08/07/08) 6.2.0_08 V10L 902138-xxL (05/11/10) 6.5.0_30 V30 902095-xx (08/07/08) B579 V30L 902122-xxL (08/07/08) B563.18 V30L 902139-xxL
902146-xxL(05/11/10) B666 V50 902091-xx (08/07/08) 6.3.2B40 V50L 902123-xxL (08/07/08) 6.3.2.B54 V50L 902140-xxL
902147-xxL(05/11/10) 6.6.2_02 V90 902094-xx (10/31/07) B550 V90L 902124-xxL (08/07/08) B611 V90L 902141-xxL
902148-xxL(05/11/10) B673