Re[2]: CF cards >32MB

[Bernd Birkenbach <Z80@xxxxxxxxx>]

Bill Moy schrieb am Mittwoch, 26. November 2003 um 19:45:13
> I believe the 32Mb limitation is based on the addressing capabilities of
> 8088 cpu technology.  I remember a discussion of this as it relates to using
> the IOMega Zip parallel external drive with such palmtops like Poqet and
> Sharp PC3K.  You might find these discussions doing a Google search of the
> software PalmZip.  For example, you can use a 100Mb Zip disk with palmtops
> but you must partition the disk into 3 drives each under 32Mb (or something
> like that.)
> Another fully satisfying explanation of this limitation is within the online
> book about assembly language "The Art of Assembly."

> Hope this helps...  --Bill

The limitation is based on the size of data fields in DOS 3.30 and
before. With DOS 3.31 the field for the logical sector number is
increased to 32 bit so DOS can address 2 TB instead of 32 MB (= 65536
sectors * 512 bytes/sector). A good source of information is Ralf
Brown's Interrupt List.
The most remarkable fact about the well known CF card driver is its
capability to use 32 bit logical sector numbers.
Therefor we need a better DOS version or write a network redirector
service which have to manage file open, close, search, rename etc on
the large CF card filesystem. Who will port ext2fs to PC3K? ;-)

Bernd