Create ISO File (MacOS)

Creating CD-ROM or DVD Image Files (MacOS)

If you experiment with vintage operating systems like I do, you’ll often need to transfer files to and from the PC. Whether this is a physical old PC or a virtual one, there is likely a time where you need to transfer files and don’t have access to a network to share the files to or from.

This is where CD-ROM images and Floppy diskette images come in handy. I’ll cover off floppy disks tomorrow but for today, let’s create a CD-ROM image from content on our local machine for use in a vintage PC build.

Creating an ISO image from Files or Folders

Step 1: Create a CDR file from Existing Files or Folders

Open the Disk Utility application (in the Utilities folder under Applications)

File,

New Image

…from Folder

Name the .CDR file e.g. WORD11A and choose a suitable file location

Choose CD/DVD Master (not hybrid CD-ROM)

No encryption

Click OK

Step 2: Convert .CDR File to .ISO File

Now that the .CDR file is created, we need to convert it to an ISO file. We can do this from the command line so open Terminal and change directory to the same folder as the .CDR file…then type:

hdiutil makehybrid -iso -joliet -ov WORD11A.iso WORD11A.cdr

That’s it!

This image can be mounted using Disk Utility but you can’t add files to it as it’s flagged as Read Only. If you need to change it, just change the files in the folder used to create the image and create another one.

Step 3: Review Content

To view content, mount the ISO file using Disk Utility 

Open Disk Utility

File, Open Disk Image, browse to your ISO file (this will mount the ISO file so you can read it)

Click OK. Now that it’s mounted, you can browse the files on it using the Finder.

When finished just Eject it like any normal removable drive in the Finder.