Hi, Austin.
There is more than one definition of "memory" and there is more than one
definition of "RAM Disk". ;^}
In the olden days, we used to be able to create a RAM disk in the computer's
memory (not on a HD of any kind). Since it was in the static RAM, it did,
as you say, disappear on power-down, and it also disappeared on a "warm
reboot". But it was MUCH faster than HD access. I used to create one when
editing text files back in the 1980s; I could save updates quickly and all
my interim revisions disappeared when I rebooted without my having to erase
them. Windows 98, as I recall, created such a RAM disk during Setup to be
used only to store installation files and then disappear; it wasn't
available for us to use after Setup.
I have not heard of a RAM disk that behaves as you describe. I do have one
of the devices that are called by a variety of names: thumb drive,
key-chain drive, USB drive, flash drive... It is just a stick of flash RAM
in a small case that plugs into the USB port, but the RAM is static, so that
it remembers when powered down or when unplugged, so it can be moved to a
different computer. Sort of a much-improved floppy that can hold much more
(mine is 128 MB, but I've seen them from about 32 to 512 MB) in a much
smaller package and access it much faster.
I think Dave is asking about the first kind - in RAM, not external at all.
They were very useful in DOS/Win3.x days; but I've not used one of those in
years, although I've heard them discussed.
RC