Subj : How to detect RAM disks (Was: how to detect cdrom?)
To   : Gerald Miller
From : Jasen Betts
Date : Fri Mar 01 2002 11:47 pm

 GM> When you know a device is installed and you know the name, then
 GM> you should be able to conduct the test for a drive letter.  From
 GM> what I've been able to determine, you are likely to get "false
 GM> positive" results if you test for the presence of a label and I
 GM> was trying to bring that fact to attention.

 GM> If someone can determine how MEM /D hooks into the memory to
 GM> determine the name of the ramdisk program (and the drive letter),
 GM> then you /_may_/ have the basis for the utility.

The name comes from the MCB the letter from the driver chain IIRC.

The problem is that while it determines those things it doesn't detrmine
that it is actually a ramdisk, just that it's a block device driver...

 excerpt from mem/d output:

                3,168    (3K)     CON       Installed Device=NANSI
               66,720   (65K)     F:        Installed Device=TESTNAME
                  224    (0K)     G:        Installed Device=DRIVER
                2,080    (2K)               FILES=40

F:  aka "testname" is from a renamed ramdrive.sys
G:  is from driver.sys and uses the same hardware as A:

telling the difference is the tricky part.
hmmm, if there was a way to figure out which one owned the huge chunk of
XMS...

AFAICT the easiest way to recognise a ramdisk is that it'll be
local, writable, non-removable, and have a single FAT

That probably won't match all ramdisks but should match most.

 -=> Bye <=-

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 * Origin: I'd give my right arm to be ambidextrous. (3:640/531.42)

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