Sorry to say, but, in Linux, there are no drive letters, only devices...

You need to know a few things about your computer system to understand device naming in Linux...

Your FIRST device is going to be /dev/hda[number]
Your SECOND device is going to be /dev/hdb[number]
THIRD will be /dev/hdc[number]
...etc...

For my system, I have a hard drive then a DVD drive, on my second IDE cable, I have a hard drive and a CD-RW drive.

My devices are as such:
/dev/hda1 -=- is my first hard drive device
/dev/hdb1 -=- is my DVD device
/dev/hdc1 -=- is my second hard drive device - first partition
/dev/hdc2 -=- is my second hard drive device - second partition
and lastly...
/dev/hdd1 -=- is my CD-RW device...

my floppy device is, pretty much the same as anyone else's, as
/dev/fd0

the numbering scheme is kinda easy to realize, once you know how your drives are partitioned, and the order of the devices on the "physical" cabling of your drives.

Primary "Master" device is going to be hda
Primary "Slave" device is going to be hdb
Secondary "Master" is going to be hdc
and Secondary "Slave" is going to be hdd

Linux sets up its devices by "physical" cabling, not like the "other" OS, which takes its devices from the cabling and BIOS. Knoppix will always use the same naming for its devices, even if you change your BIOS, becuase to change the names in Linux, requires changing physical cabling changes.

In Windows, you can "fake" windows into thinking the C: is actually the D:, and the D: is the C:, by changing the BIOS to boot either the second hard drive, or the first hard drive. In Linux, this trick doesn't work, becuase Linux goes off the cable order of the devices, which won't change unless you change the order of your drive cables.

Any device in Linux is going to be /dev/[something]1 -=- i.e. /dev/hda1, /dev/hdb1, etc...

On hard drives, you can have multiple partitions, either primary, secondary, etc... (where is Stephen when I need him )

the first partition on a device is going to be "1", the next primamry partition is going to be "2", etc...
a secondary partition on the same device, I think its called a "logical" partition, I think the numbers start at "5" and go up by one...

my second hard drive, see above, has two PRIMARY partitions on it, so they are device labeled: /dev/hdc1 and /dev/hdc2, if I had a third "logical" partition on this same device, it would be labeled /dev/hdc5, and another would be /dev/hdc6, etc...

(did I do good Stephen )

After you get Knoppix up and running, you might want to run "cfdisk" on your system to view the order of things - this command would be run in a command line interface - or CLI - or the same icon along the bottom of the screen that looks like a screen with a shell in front of it.

To find out the order of how your devices are labeled, you can also run "dmesg" from this same CLI - scroll up to near the top of the output and you will see what devices were found, what they are, and what labeling they were given. You will be asked, when you are saving anything, which "device" you want to save to. In my case, I get a list of the following:

/dev/hdc1
/dev/hda1
/dev/hdc2
/dev/fd0

here is a "snippet" output of my output for dmesg, showing my devices, and what the labels are for them:

Code:
cuddles@Polaris:~$ dmesg

[...snip...]

Floppy drive(s): fd0 is 1.44M
FDC 0 is a post-1991 82077

[...snip...]

hda: HDS722540VLAT20, ATA DISK drive
hdb: SONY DVD-ROM DDU1611, ATAPI CD/DVD-ROM drive
hdc: SAMSUNG SP0802N, ATA DISK drive
hdd: OPTORITECD-RW CW5201, ATAPI CD/DVD-ROM drive

[...snip...]

hda: attached ide-disk driver.
hda: host protected area => 1
hda: 80418240 sectors (41174 MB) w/1794KiB Cache, CHS=5005/255/63
hdc: attached ide-disk driver.
hdc: host protected area => 1
hdc: 156368016 sectors (80060 MB) w/2048KiB Cache, CHS=9733/255/63
ide-cd: passing drive hdb to ide-scsi emulation.
ide-cd: passing drive hdd to ide-scsi emulation.
hdb: attached ide-scsi driver.
hdd: attached ide-scsi driver.
Partition check:
 hda: hda1 hda3
 hdc: hdc1 hdc2

[...snip...]

SCSI subsystem driver Revision: 1.00
scsi0 : SCSI host adapter emulation for IDE ATAPI devices
  Vendor: SONY      Model: DVD-ROM DDU1611   Rev: GYS1
  Type:   CD-ROM                             ANSI SCSI revision: 02
  Vendor: OPTORITE  Model: CD-RW CW5201      Rev: 160E
  Type:   CD-ROM                             ANSI SCSI revision: 02
Attached scsi CD-ROM sr0 at scsi0, channel 0, id 0, lun 0
Attached scsi CD-ROM sr1 at scsi0, channel 0, id 1, lun 0
sr0: scsi3-mmc drive: 0x/40x cd/rw xa/form2 cdda tray
Uniform CD-ROM driver Revision: 3.12
sr1: scsi3-mmc drive: 52x/52x writer cd/rw xa/form2 cdda tray

[...snip...]
One special note here, even though my CDROM devices are on hdb and hdd, they get passed to a SCSI controller for support, this is done ALL THE TIME, with Knoppix - so my real devices for my DVD are /dev/sr0 and my CDRW is actually /dev/sr1

Take note of what the device names are for my setup, and how they are described, this will help you locate and decide on the labeling of your own devices on your system.

(GOD) I hope this helps, (STEPHEN HELP )
Cuddles