Panasonic fp2/fp2sh User Manual page 234

IC Memory Card
7.4 For Use as Expansion Memory
2) Using the remaining DOS formatted field
All of the remaining DOS formatted field can be used as expansion memory.
Example: When 512 kB is set as the DOS formatted field in a 1 MB card
1 MB
7 − 24
DOS
512 kB
512 kB
Address
0
Expanded memory field
262144
FP2/FP2SH