CD-ROM Drive Not Found in DOSBox? MOUNT and IMGMOUNT — In Plain Words

First, the big idea — DOSBox shows nothing until you mount it

The manual’s Quickstart says: “It is essential that you get familiar with the idea of mounting, DOSBox does not automatically make any drive (or a part of it) accessible to the emulation.”

Mounting means connecting something real to a drive letter inside DOSBox. The wiki’s MOUNT page says it this way: “MOUNT.COM is a command inside DOSBox that can connect physical folders and drives to virtual drives inside DOSBox.”

The manual says the same thing in plain words: “Basically MOUNT allows you to connect real hardware to DOSBox's emulated PC.”

So “CD-ROM not found” often just means: no CD drive has been mounted yet.

MOUNT or IMGMOUNT — which one do you need?

Use MOUNT for a real drive or a real folder on your computer.

Use IMGMOUNT for a disc image file. A disc image is one file that holds a copy of a whole disc. The IMGMOUNT wiki page calls it “A utility to mount hard disk and optical disc images in DOSBox.” The manual calls IMGMOUNT “A utility to mount disk images and CD-ROM images in DOSBox.”

The manual draws the line in one sentence: “If you want to mount a CD image or floppy image, check IMGMOUNT.”

Way 1 — a real CD drive, with MOUNT

The manual’s CD-ROM answer says: “To mount your CD-ROM in DOSBox you have to specify some additional options when mounting the CD-ROM.”

For Windows, the manual gives this command:

mount d f:\ -t cdrom

Read it in three parts, using the manual’s own explanation:

• d — “driveletter you will get in DOSBox (d is the best, don't change it!)”
• f:\ — “location of CD-ROM on your PC. In most cases it will be d:\ or e:\” Use the letter your own computer gives your CD drive here.
• -t cdrom — the part that tells DOSBox this is a CD-ROM drive. The next section explains why it matters.

The manual gives the same job a second way in its list of basic MOUNT examples: “To mount your CD-ROM drive E as CD-ROM drive D in DOSBox:”

mount d e:\ -t cdrom

The wiki’s MOUNT page gives the same form in capital letters:

MOUNT D D:\ -t cdrom

For Linux, the manual gives:

mount d /media/cdrom -t cdrom

The manual also says which letters to use for each kind of drive: “HardDisk should always be mounted as c”, “CD-ROM should always be mounted as d”, and “Floppy should always be mounted as a (or b)”.

And if your game is on CD, the manual says you need both drives at once: “So if you have the game on CD you always (even after installation!) have to mount both: folder as a harddisk drive and a CD-ROM.”

Why -t cdrom matters — MSCDEX

MSCDEX is the name the manual uses for the CD-ROM interface DOS games use to talk to a CD drive.

The manual’s CD-ROM answer says the Windows command above is “To enable CD-ROM support (includes MSCDEX)”.

Its “can’t find its CD-ROM” answer says it even more directly: “Be sure to mount the CD-ROM with -t cdrom switch, this will enable the MSCDEX interface required by DOS games to interface with CD-ROMs.”

In plain words: if you mount the drive without -t cdrom, DOSBox may show the files, but the game may still say it cannot find its CD-ROM, because the game is looking for a CD-ROM drive, not just a folder of files.

The manual’s MOUNT section lists what -t can be: “Type of the mounted directory. Supported are: dir (default), floppy, cdrom.” So cdrom is the type you must ask for by name.

The manual adds one warning about using a plain folder this way: “It's possible to mount a local directory as CD-ROM drive, but hardware support is then missing.”

If the game still cannot find its CD — try the label

A label is the name written on the CD itself. The manual calls it the “CD-label (volume ID) of the CD-ROM”.

The manual’s “can’t find its CD-ROM” answer says: “Also try adding the correct label (-label LABEL) to the mount command, where LABEL is the CD-label (volume ID) of the CD-ROM.”

The manual’s MOUNT section explains the same option: “Sets the name of the drive to ‘drivelabel’. Needed on some systems if the CD-ROM label isn't read correctly (useful when a program can't find its CD-ROM).”

The wiki’s MOUNT page describes it as: “-label [name] = Set the volume name of the drive (all caps)”, and its full example is:

MOUNT D D:\ -t cdrom -usecd 0 -ioctl -label GAME_CD

In that example, GAME_CD stands in for the real label of that example’s disc. Use your own disc’s label in its place.

Way 2 — a disc image file, with IMGMOUNT

The IMGMOUNT wiki page gives this general form:

IMGMOUNT DRIVE [imagefile] -t [image_type] -fs [image_format]

Its Windows example for an ISO image is:

imgmount d "C:\MyISO.iso" -t iso

That example appears on the wiki page as a short set of steps: first mount c "c:\images", then the IMGMOUNT line above, then d: to move to the new drive.

The wiki’s MOUNT page gives the same idea in its own examples:

IMGMOUNT E C:\Images\MyImage.iso -t iso

IMGMOUNT E C:\Images\MyImage.cue -t iso

For a CUE file, the IMGMOUNT wiki page gives this Windows example, with one extra part:

imgmount d "C:\cdimg.cue" -t iso -fs iso

The manual also gives IMGMOUNT examples for more than one CUE image at once. Its Linux example is:

imgmount d /tmp/cdimage1.cue /tmp/cdimage2.cue -t cdrom

Note the difference and do not mix the two up: the manual’s IMGMOUNT examples use -t cdrom, and the wiki’s IMGMOUNT examples use -t iso. Both forms are printed above exactly as each source prints them.

Which image types do the docs name?

Only these. The manual says: “It is possible to mount CD-ROM images (ISOs or CUE/BIN or CUE/IMG) too.”

The manual also says: “CUE/BIN pairs and cue/img are the preferred CD-ROM image types as they can store audio tracks compared to ISOs (which are data-only). For the CUE/BIN mounting always specify the CUE sheet.”

In plain words: a CUE/BIN pair is two files that work together, and you mount the CUE file, not the BIN file. The IMGMOUNT wiki page says the same thing from the other side: “Specifying the associated .cue file will load all tracks correctly”, while mounting the .bin file on its own “will not mount the audio tracks of the CD correctly”.

The IMGMOUNT wiki page describes the iso type this way: “Specifies an optical disc iso image. The geometry is automatic and set for this size. This can be an iso or a cue/bin.”

The manual describes its cdrom type for IMGMOUNT this way: “Specifies a CD-ROM image. The geometry is automatic and set for this size. This can be an iso or a cue/bin pair or a cue/img pair.”

The manual’s “can’t find its CD-ROM” answer points to this route as well: “Try creating a CD-ROM image (preferably CUE/BIN pair) and use the DOSBox's internal IMGMOUNT tool to mount the image (the CUE sheet). This enables very good low-level CD-ROM support on any operating system.”

A short check list, in order

• Step 1. Did you mount anything at all? DOSBox does not make any drive available on its own.
• Step 2. For a real drive, did the command end with -t cdrom? Without it, the manual says the MSCDEX interface the game needs is not enabled.
• Step 3. Is the CD mounted as drive d? The manual says the CD-ROM should always be mounted as d, and the hard disk as c.
• Step 4. Does the middle part of the command match your real computer? In mount d f:\ -t cdrom, the f:\ part is the location of the CD-ROM on your PC — use your own drive’s letter there.
• Step 5. If the game still cannot find its CD, add the disc’s correct label with -label, as the manual’s answer directs.
• Step 6. If you are using an image file instead of a real disc, use IMGMOUNT, and for a CUE/BIN pair, mount the CUE file.