Hi, I think it would be really interesting to have PCMCIA drive,
for example compact flash, support in DOS. Not with hotswapping,
but a nice idea would be a device driver which initializes PCMCIA
to activate the IDE controller to the CF card, and then tweaks
BIOS data (40:xx data segment and maybe EBDA) to tell the BIOS that
there is now one IDE controller more. Then the driver can access
the disk with help of the BIOS (or read the sources of the DOS UDMA
driver to learn how to do directly... well, actually PCMCIA does
not normally support DMA at all, but the IDE controller communication
is still very similar). It can read the partition table and offer the
FAT partitions as normal block devices (comparable to RAMDISKs) for
normal DOS access.

Some nice code fragment which could help to get such a driver
project started (you will have to add code from kernel initdisk
and from a RAMDISK plus the abovementioned BIOS and/or IDE magic)
has been donated by Deskwork (shareware GUI with file meta-info-
database instead of long file names, and with some built-in drivers)
project:

http://www.coli.uni-sb.de/~eric/stuff/soft/by-others/deskwork-unit-pcmcia.pas

Not that I would have any time for a PCMCIA driver project, but
maybe it is good to remind the people of the list that we already
do have several building blocks for one :-).

Eric

PS: Another interesting project would be a read-only block device
which is fed by a disk image (possibly compressed!) and thereby
only uses little XMS. It can use int 2f.122x (meant for NLSFUNC
in the first place) file open / read interface to avoid most re-
entrancy problems (apart from not being able to load country sys
from the diskimage device ;-))...



-------------------------------------------------------
This SF.Net email is sponsored by: InterSystems CACHE
FREE OODBMS DOWNLOAD - A multidimensional database that combines
robust object and relational technologies, making it a perfect match
for Java, C++,COM, XML, ODBC and JDBC. www.intersystems.com/match8
_______________________________________________
Freedos-devel mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/freedos-devel

Reply via email to