Debian on my Targa laptop, again ...
It's me again ... Since I think many of you could be interested, and I
got personalized answers (thank you !) I'd like to reply to. So there
are the latest developments :
I am now able to get to my USB memory key; actually, I had the idea to
boot once with that key plugged in, and it worked : there was the
/dev/sda device I wanted !
Mounting it wasn't a problem any more.
Next thing I tried : reboot, without the key. I went a bit different :
apparently, no more /dev/sda, but as soon as I plugged it on again,
hotplug told me it had just detected it and a /dev/sda device was
created "on the fly"...
Well, things seem to progress, slowly I confess, but steadily.
Thank you all.