Home |  | Index
| Introduction
About FreeDMG This software allows the user to perform drag-and-drop disk imaging on the fly. Both the program's window, and the dock icon can be used for drop imaging. There are currently twelve (12) compression form ats that the user can select from (UDZO, UDCO, etc.). Users may also choose to make internet enable disk images. Verbose preference, and log window help users hide/display additional information about the current image. The "Images" menu contains many options for creating and manipulating disk images. This is accompanied by the addition of adjustable compresion levels in preferences (with UDZO format only), the option to overwrite exising files, and and option to quit after imaging on dock drop launch.. Users can also now ecnrypt (password protect) images with the click of a button, and more! About Disk Images You can use FreeDMG to create a disk image, which is a file that contains other files and folders that you can mount on your desktop like a hard disk. You can create a disk image from an existing disk, volume, or folder. You can also create a blank disk image and copy files to it. Double-clicking a disk image mounts it on your desktop, where it looks like a hard disk. You can read the files on the image and copy files from it to your hard disk. If you created a read/write disk image, you can also copy files from your hard disk to the image and edit the image’s files. Use disk images to move files from one Mac to another, send them to other Mac users via email, or burn the image on a CD or DVD disc as a for safekeeping. Disk images are also a convenient way to back up and restore your system software and files. Disk images were first invented to electronically store and transmit representations of floppy disks for manufacturing replication. These images of floppies are typically referred to as 'Disk Copy 4.2' images, in reference to the application that created these images and restored them to floppy disks. Disk Copy 4.2 images were block for block representations of a floppy disk, with no notion of compression. DART is a variant of the Disk Copy 4.2 format that supported compression of the floppy image. NDIF (New Disk Image Format) images were developed to replace the Disk Copy 4.2 and DART image formats and to support images larger than a floppy disk. With NDIF and Disk Copy version 6, images could be "attached" as mass storage devices under Mac OS 9. Apple Data Compres- sion (ADC) -- which carefully optimizes for fast decompression -- was used to compress images that were typically created once and restored many times during manufacturing. UDIF (Universal Disk Image Format) device images picked up where NDIF left off, allowing images to represent entire block devices and all the data therein: DDM, Apple partition scheme partition map, disk-based driv- ers, etc. For example, it can represent bootable CD's which can then be replicated from an image. To be single-forked (vs. the dual-fork NDIF), it began storing its metadata in an embedded resource. UDIF is the native image format for OS X. Raw disk images from other operating systems (e.g. .iso files) will be recognized as disk images and can be attached and mounted if OS X recognizes the filesystems.