Puppy Linux 5.1: HDD not mountable (SD-card in a CF-adapter in an IDE-adapter)

The HDD which is an SD-card in a CF-adapter in an IDE-adapter is not
listed among the mountable devices. I have a Thinkpad T20 w/ 192 MB RAM
and boot Puppy 5.1 from CD-R. I already have an earlier version of Puppy
installed on the SD-card and I can still boot that if I remove the CD-R.
My intention was to install the new Puppy on the HDD (which is an
SD-card). I cannot easily remove the SD-card since it was extremely
difficult to fit the IDE-adapter. Any idea how I could install to the
SD-card/HDD when it's not even discovered by the mount system?