Mail Archives: opendos/1997/02/04/17:24:00
> I'd slow down there yourself Brian... The IFS module system is only so
>the OS can read extra Filesystems other then FAT.. an example config.sys
>might have:
>
>IFS=c:\opendos\ext2.sys
>IFS=c:\opendos\vfat.sys
>
> Now the OS could read/write to FAT, EXT2, or Windows 95's LFN FAT
>system without seperate programs (dir, copy, etc..) used for each.
Exactly. If I can reiterate:
The way I envision it as something as follows. Say we have a totally standard
kernel, OpenDOS 7.01. Yes, this is the one we all have installed now. This has
FAT12 and FAT16 support built in. It will load, find (on my system) /dev/hda1
which is a FAT16 partition and mount it on C:. It will also find /dev/hdb1, a
FAT12 partition, and mount this on D:. Then it runs the CONFIG.SYS file:
DEVICE=C:\SYSTEM\UTILS\EXT2.SYS Ext2 IFS. This will find /dev/hdb2, my
ext2 partition, and mount it on E:.
DEVICE=...cd driver... Device specific CD driver. I need this
because DOS can't see the CD drive. This
is *not* an IFS module, though.
DEVICE=C:\SYSTEM\UTILS\ISO9660.SYS Otherwise known as NWCDEX. This
allocates a drive, F:, for and CD's.
DEVICE=C:\SYSTEM\UTILS\MINIX.SYS Minix IFS. I don't have any Minix
partitions, but it stays in memory
anyway. If I insert a Minix floppy in
drive A, I'll see it.
So, now I have four drives: C, FAT16; D, FAT12; E, ext2; F, CD-ROM. (I also
have G, a Stacker drive, but that uses a different interface and doesn't have
to be explicitely loaded.) I don't have to use any special programs to access
any of them. This will work:
C:
CD \GAMES
DIR
or
E:
CD \USR\LOCAL\LIB\MUSIC\MODULES
DIR
or (if I insert a CD)
F:
CD \PCGEOS\APPL\SDK_C
DIR
This can be done NOW. TODAY. Using EXISTING API's, EXISTING technology. I
don't even need to recompile anything. All that has to be done is to find out
how. It's perfectly possible --- NWCDEX does it, Personal Netware does it, XFS
(an NFS client) does it, Interlink does it, Doublespace does it, Stacker does
it... If the CONFIG.SYS is trashed, nothing goes wrong because FAT16 and FAT12
are built in to the kernel.
Other IFS devices may include VFAT.SYS, UMSDOS.SYS, HFS.SYS (for Mac discs),
XIAFS.SYS (for die-hard Linux users), even maybe PKZIP.SYS and TAR.SYS for
viewing archives. All installable if you want them.
A file system is just another driver. Try doing MEM /A. You'll see a list of
all the drivers; there'll be a field beside each one for a device name. For
example, I get (among others) CLOCK$ and PC$MOUSE. These are device files
along the same lines as COM1, NUL, LPT1. (Try TYPE CLOCK$.) You'll also see
drive letters there. That means that that device acts as a complete drive and
not a simple file. It's using the IFS API.
I'm sorry if I'm hammering this home too hard, but some people appear to be a
little confused about what an IFS actually is...
[Please do not cc: replies to me if they're also going to the list! I get
enough email at the best of times without getting things twice]
--
------------------- http://www-hons-cs.cs.st-and.ac.uk/~dg --------------------
If you're up against someone more intelligent than you are, do something
totally insane and let him think himself to death. --- Pyanfar Chanur
---------------- Sun-Earther David Daton Given of Lochcarron ------------------
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