Well, I never expected a simple question to spark off such a heated debate!
The reason I asked was that I had an LGCIU1 fail (IAE 320) and on ECAM, REV1 was listed as inop. I was both knackered and not within reach of a tech manual, so I was hoping for the answer.
Thanks, SLT and others, it's all coming back to me! Best I get back in the manuals!