@Jose:
Atleast on my WE the three termination-resistor-packs are socketed and to disable the WE onboard termination you just have to remove them.
The termination power should not be disabled as the terminators on the scsi-chain needs power atleast from one source.
I dont really understand what you mean with: "If not this will probably cause all kinds of problems cause the chain will be terminated right at it's beginning.", but I can say that if you remove the termination resistors from the WE and thus disable its termination, it will be perfectly fine to connect the termination end of the UW-cable to the WE (using that adapter).
Also, as I said earlier about terminating the whole width of the bus. If you use UW-drives, you also need to terminate the upper byte of the bus, which the WE cant, unless your adapter includes upper byte termination. The terminator attached to the UW-cable will terminate the entire bus-width plus it is an active terminator, whilst the WE-terminator is passive, which is more or less crap for the integrity of the signals on the bus.
Keep in mind though that your adapter should be without upper byte termination for this to work ok, or else the upper byte will be double-terminated. Most F-F 50<->68 adapters doesnt include this, but it might be worth checking out.
Check
this page for a lot of good and rather detailed info about SCSI termination, termination power, 50->68 and 68->50 adapters etc.
/Patrik
