> Is there a link where are indicated the revisions of all the boards > manufactured by bplan/genesi ?
There are five revisions of the Pegasos II board, 2B1 through 2B5. You can find it printed on the board itself.
> I also read somewhere, maybe here, that I could put a single 2 mb memory module. > Is it possible or not ? Would/could I have some freezes randomly or not ?
I'm not aware that a single 2 GiB module (or even 4 GiB module) was ever tried so far. There may or may not be problems with the SmartFirmware in general (or particular revisions thereof) or particular board revisions to properly recognize such module. On pegasosforum.de there's a (German) thread on this topic, so far without report of any findings unfortunately:
However, as you can see in this thread, for a configuration of two 1 GiB modules Genesi also recommends a certain type of Kingston RAM.
> On their web site crucial knows genesi pegasos 1 and 2 computers and > they can propose memory modules for both.
As far as I can see, the maximum they offer as "Guaranteed-compatible upgrades for your Genesi Pegasos II" is 1 GiB modules, so no 2 GiB modules like you asked about.