1. To create disk image files quickly and efficiently:
Using ShrinkWrap, you can create disk image files by simply dragging and dropping your disk icons onto the ShrinkWrap icon. In Batch Floppy Mode, you can continue to feed in floppy disks until your entire archive has been converted into image files without ever needing to touch the mouse or keyboard.
To convert your image files back to disk, just select the image files, hold down the Command key and drag the icons onto the ShrinkWrap icon. You will be prompted to insert a disk as each image is written back to floppy disk. In Batch Floppy Mode, multiple copies of each image file may be made. Just select Stop when you’ve made enough copies of each image.
2. To provide a convenient and reliable means of mounting disk image files on the desktop:
Like Apple's MountImage control panel, ShrinkWrap will mount image files on the desktop that to the system will appear identical to the original floppy disks. However, since ShrinkWrap is an application, it will never cause INIT conflicts and will never require any memory until it's actually run. To mount image files, simply drag and drop the image file icons onto the ShrinkWrap icon. Image files can be mounted as unlocked disks by holding down the Shift key during launch and even loaded into free memory to get the performance of a RAM disk just by setting an option in preferences.
3. To seamlessly handle disk image files in their archived form:
ShrinkWrap will automatically compress and decompress archived disk image files on the fly with Aladdin's StuffIt Engine. Now that the StuffIt Engine has been released as shareware in DropStuff, you don't even have to own StuffIt Deluxe to take advantage of these convenient compression features.
4. To provide a freely distributable alternative to Apple's DiskCopy, DART and MountImage:
DART and MountImage cannot yet legally be licensed for redistribution. Apple Computer, Inc. is working to create a license, but until that time, you may not legally redistribute it once you receive a copy from an authorized Apple source. DiskCopy is available for licensing, but at an often prohibitive cost of $5000 per year.
Installation
Install ShrinkWrap by decompressing the StuffIt archive and dragging the ShrinkWrap application to a convenient location on your hard drive. You may need to rebuild your desktop if ShrinkWrap will not initially accept drag and drop files. Ideally, you will already have the StuffIt Engine installed in your Extensions folder. If not, you should obtain Aladdin's StuffIt Deluxe or DropStuff and install the software from <http://www.aladdinsys.com/>.
System Requirements
ShrinkWrap is a System 7-only application for Macintosh and Power Macintosh. It contains both 68K and PowerPC native code, is AppleEvent aware, 32-bit clean, AV, ’040 cache and virtual memory compatible. Although a Macintosh SE or better is required for full functionality, the Mac Plus can still use ShrinkWrap to mount, convert and verify disk image files.
Supported Image File Formats:
Mount Volume
Locked Unlocked Create Write Convert Verify Image File Format
• • • • • • ShrinkWrap
• • • • • • ShrinkWrap Self-Mounting
• • • • • • ImageMaster
• • • • • • Apple DiskCopy 4.2
• • • Apple DiskCopy 5.0d1 - 6.0
• • • Apple Disk Image Mounter
• • • Apple DART 1.5.1 - 1.5.3
• • • DiskMaker 1.3
• • • • • • PC Exchange Drive Containers
• • • • • • DropDisk 1.0b5
• • • • • • DiskDup+
• • • Norton Floppier
• • • CPS FastCopy (uncompressed)
• • • • • • Microsoft Disk Image Utility (.IMG)
• • • • • • Winimage (.IMA)
Introduction
Why do we need to deal with disk images?
Although there is some similarity between disks duplicated from disk images and disks copied by dragging icons, the results are not identical. Disks created from image files are exact duplicates, including the exact icon placement, appearance of all windows, and the correct name of the disk. In addition, with disk images you have the added assurance that all the files have been duplicated correctly and completely. More importantly, Apple's Installer may not recognize disks copied by dragging icons, even if they appear identical in every way.
Some convenient uses for disk images:
1. Backing up your original floppy disks to removable media:
A Magneto-Optical, Iomega, Bernoulli, SyQuest or CD-R drive can serve as an excellent means to back up your software. When disk image files are stored in compressed form, they are space efficient but still easily accessible with ShrinkWrap. Just drag the compressed image onto the ShrinkWrap icon and the file will be uncompressed and immediately mounted on the desktop.
2. Installing Apple's System Updates and System Software Extensions:
Since most of Apple's System Software, System Updates and System Extensions (CD-ROM Setup, Network System Installer, printer drivers, etc.) are distributed online in image file format, it's convenient to be able to mount the images and run the Installer without ever having to copy the images back to floppy disk.
3. Distributing multiple disk images on floppies:
Using ShrinkWrap and the StuffIt Engine, you can achieve adequate compression to store three or more 800K disk images on a 1.44 MB HD floppy.
4. Mounting floppies on Macs without a SuperDrive:
For Macs not equipped with a SuperDrive, ShrinkWrap provides a cost-effective and convenient means of accessing data stored on floppy disks.
5. Creating “instant” RAM disks:
Placing a ShrinkWrap disk image file in your Startup Items folder will make it always available from startup, just like a RAM disk. However, when you’re done with the ShrinkWrap RAM disk and need to free up the memory, just drag the mounted image to the trash. No need to restart.
6. Distributing software collections and archives on CD-ROM:
Provide a convenient and economical means for your customers to obtain copies of their software on floppy media even if your product is now being distributed exclusively on CD-ROM. With ShrinkWrap's extensive AppleScript support, you can even offer users the ability to create floppies directly from your product's installer.
7. Verifying the integrity of development builds:
ShrinkWrap can provide 32-bit checksums for use in confirming the data integrity of floppies or CD-ROM’s when it's absolutely vital that you ensure an exact copy was made.
Using ShrinkWrap
Drag and Drop:
You will probably find that the most efficient way to use ShrinkWrap is via the drag and drop interface. By placing the ShrinkWrap application or an alias to ShrinkWrap on your desktop, you can have quick access to almost all features just by dragging files, folders or volumes onto the ShrinkWrap icon.
1. The default actions for drag and drop are as follows:
- Image files: These are mounted on the desktop just as if you had used the Mount Image command from the Image menu and selected each file individually.
- Disks: Exact copies of these volumes are created and saved as disk image files, just as if you had use the Create Image from Disk menu command and selected each volume.
- Folders: A new image file is created, mounted and filled with the contents of the folder, just as if you had selected the Mount Folder menu command for each folder.
>> Note: Any combination of file, folders or disks can be dropped onto ShinkWrap, but the order in which they are processed can be unpredictable. <<
2. Modifier keys can be held down while you drag and drop an icon or group of icons onto ShrinkWrap to change the behavior:
- Shift: Holding down this key will cause disk image files to be mounted as unlocked disk so that write operations are allowed.
- Command: Holding down Command will cause disk images to be written back to disk. In the case of disk image files, this is the same as the Write Image back to Disk menu command. For disks, this is equivalent to the Duplicate Disk command.
- Control: Holding down Control will calculate 32-bit checksums for the disk images, just like the Verify Image and Verify Disk menu commands.
- Shift-Control: Holding down Shift and Control will convert image files of all readable types to the current writeable image format as selected in Preferences, just like the Convert Image menu command. For example, if ShrinkWrap Self-Mounting is selected in the Floppy pop-up menu under “Save disk image files as:”, dragging a group of DiskCopy icons onto ShrinkWrap while holding down Shift-Control will convert each of these disk image files to a self-mounting image file.
- Option: Holding down the Option key will bring up a one-time Preferences dialog that will allow you to make temporary changes to your Preference options. These changes will stay in effect until you quit the application or enter the Preference dialog and press OK.
>> Note: In order for ShrinkWrap to tell that you've held down a modifier key, you must keep it depressed until the progress dialog appears. <<
3. All options in Preferences are also in effect for drag and drop. For example, if the “Automatically decode and expand archives” option is enabled (as it is by default), archived and encoded files will be handed off to the StuffIt Engine for preprocessing and the files that the StuffIt Engine returns will be handled by ShrinkWrap. If a folder is returned, it will be searched recursively to find image files that can be processed.
Show Log:
The ShrinkWrap Log is a report of all operations that have been conducted since the beginning of the session, including dates and times, detailed information on the disk images processed, checksums and errors. You can view the log at any time by selecting the Show Log command from the Edit menu. The contents can be copied to the clipboard or saved to disk as a SimpleText document using the standard Save or Save As menu commands in the File menu. If you close the Log windows later or quit, you will be prompted to save the log file.
>> Note: If you decline to save a log, you can always reopen it later. The log is created on launch and runs continuously until you quit the application. By selecting the Show Log command or Close, you just control when it's visible. <<
>> Note: The Verify Image and Verify Disk commands will automatically open the log when they complete so that you can examine the results of the verification and record checksum values. <<
Preferences:
1. The group of four “Destination:” radio buttons indicate where the image files and StuffIt archives created by ShrinkWrap should be stored. Selecting “Same as ShrinkWrap” will use the folder where the running ShrinkWrap application currently resides. Selecting “Same as original” will use the folder (or desktop) that contains the original image file or disk. Selecting “Prompt for destination” will prompt you for a destination with a standard file dialog at runtime. Finally, selecting “Use:” will allow you to specify a folder of your choice. Note that you should always choose your destination folder to be located on an unlocked volume with plenty of free disk space.
2. The “Select” button allows you to choose a specific folder as the destination folder. If ShrinkWrap for some reason can't find this folder on startup, it will default to the startup volume desktop folder.
3. Checking the “Automatically decode and expand archives” check box will cause any archive format currently supported by the StuffIt Engine (.hqx, .uu, .bin, .sit, .sea, .cpt, .pkg, .zip, .arc, .gz, and .Z) to be automatically expanded to locate image files.
4. Checking the “Delete archive after expanding” check box deletes the archive from the disk after it has been expanded into its original image file. Use this feature carefully.
5. Checking the “Delete expanded files after processing” check box deletes all decoded and/or expanded files and folders from the original archive after they are no longer needed by ShrinkWrap. This will automatically clean up the transitional folders and files that are created as you mount, write, convert or verify compressed image archives, freeing up space on your hard drive and keeping your workspace uncluttered.
>> Caution: Selecting options to delete the original archive and all the expanded files will leave no copies remaining of your original images. Be sure your data is backed up or expendable. <<
6. Checking the “Automatically compress image files” check box will cause all image files created with ShrinkWrap to be automatically compressed into their own StuffIt archive.
7. Checking the “Delete original after compressing” check box deletes the original image file from the disk after it has been compressed into an archive.
8. Checking the “Encrypt archives with password” check box will encrypt all image files created with ShrinkWrap using a password of your choice or a randomly generated password. Make sure to remember your password! You will need it to expand any encrypted images in the archive.
9. Checking the “Make archives self-extracting” check box will create self-extracting archives that anyone can decompress, even without a StuffIt product.
10. The two pop-ups under “Save disk image files as:” indicate what image file format should be used to save images of floppy disks and other volumes like CD-ROMs, hard drives and removables. Disk image files are generated using the New Image, Mount Folder, Create Image from Disk and Convert Image commands.
11. Checking the “Keep mounted images in RAM” check box will instruct the ShrinkWrap driver to load mounted images completely into RAM if there's enough free memory available.
Here is a quick review of the advantages of each method:
a. Mounting images into RAM:
- Images mounted in RAM are lightning fast (just like a RAM disk).
- Images mounted in RAM never require any free hard drive space.
- The original images are less susceptible to corruption if your computer crashes.
b. Mounting images directly from the hard drive or server:
- Each mounted image requires <1K of RAM.
- Mounting images occurs much faster, since the entire image file need not be immediately loaded into memory.
- The maximum number of mounted image files is not limited by available RAM.
12. Checking the “Mount images unlocked by default” check box will cause ShrinkWrap to reverse the normal behavior of the Shift key, causing image files to be mounted as unlocked volume normally and to be mounted as locked volumes if the Shift key is held down.
13. Checking the “Auto-size mounted folders” check box will cause ShrinkWrap to skip the New Image dialog when creating the image file to mount a folder and use the suggested size that is normally displayed as the default value in the edit box. This value is calculated to take into account the allocation block size of the new volume, overhead for the Boot Block, Master Directory Blocks, Volume Information Blocks, Catalog Tree and Extents Tree. However, the means of determining the probably size of the desktop database on the new volume is an intelligent guess based on the number of files contributing bundles to the database. You will likely have a few K left free on the new volume and there is the potential that there may not be room enough on the drive to build a full desktop database.
14. Checking the “Verify mounted image checksums” check box will cause ShrinkWrap to verify the checksums of each image file prior to mounting it on the desktop. This provides a means of confirming the data integrity of the image file prior to it being mounted, although at a noticeable performance cost. If you mount images from a network or CD-ROM, the verification process can take several seconds.
15. Checking the “Verify tag checksums” check box will cause ShrinkWrap to verify checksums of the tag data, if it exists for an image. Tag data is the extra 12 bytes of "scavenger" information present on 400K and 800K Macintosh floppies. Since Apple no longer uses or supports tag data, it is no reflection of the actual integrity of your data. Additionally, DiskCopy will occasionally calculate a different tag checksum for 400K and 800K images than that generated by ShrinkWrap and DART, causing the image to fail checksum verification and be rejected, despite the fact that the actual data is uncorrupted. Unchecking this option will allow those image files to be processed, despite the tag checksum discrepancy.
16. Checking the “Verify destination disk checksums” check box will provide an additional verification pass when copying image files to disk or conducting disk-to-disk copies to verify that checksums on the destination disk match the original. This verification pass is in addition to sector-by-sector verification already done by the driver.
17. Checking the “Confirm overwriting destination disk” check box will cause a confirmation dialog to be displayed each time you are about to overwrite a formatted floppy disk.
18. Checking the “Batch Floppy Mode” check box will allow you to efficiently conduct batch operations on large quantities of floppy disks. Just keep feeding in disks and ShrinkWrap will continue to create image files, duplicate a disk image or verify the disks. When you're done, just press Stop.
Menu Commands:
New Image - To create and mount a new blank disk image file on the desktop, do the following:
1. Select the New Image command from the Image menu.
2. Type in the name of the volume, or accept the default name “Untitled”.
3. Select the radio button to indicate whether you want to create a floppy disk image or larger volume.
4. If you chose the Floppy option, select the size and file system from the pop-up menu.
5. If you chose the Other option, type in the size of the volume you wish to create in K.
6. Hit the OK button.
Mount Image - To mount a disk image file on the desktop so that it acts like a virtual floppy disk, do the following:
1. Select the Mount Image command from the Image menu.
2. Select the image file you wish to mount from the standard file dialog.
3. Check the option to mount as unlocked on the bottom if you need read/write access to the mounted disk.
4. Hit the Open button.
>> Note: Image files can be mounted only if they are located on local Macintosh disks or AppleShare servers. If you attempt to mount an image file that is on a PC disk or mounted image, you may receive an error. <<
Mount Folder - To create and mount a new disk image file with the contents of a folder, do the following:
To create and mount an image with the contents of a folder from within the ShrinkWrap application:
1. Choose the Mount Folder command from the Image menu.
2. Select a source folder using the standard file dialog.
3. If the “Auto-size mounted folders” option is set in Preferences, you're done. Otherwise you'll see the New Image dialog.
4. Type in the name of the volume, or accept the default name from the folder.
5. Select the radio button to indicate whether you want to create a floppy disk image or larger volume.
6. If you chose the Floppy option, select the size and file system from the popup menu.
7. If you chose the Other option, type in the size of the volume you wish to create in K or accept the default value to size the new volume to the contents of the folder.
8. Hit the OK button.
>> Note: If you select a size for the new volume that is too small for the folder contents, a “Destination disk is full” error may result and the contents of the folder will be incompletely copied. Under certain circumstances, you may be unable to unmount the mounted image file by dragging it to the trash. If this is the case, you will need to restart your Mac. <<
Unmount Image - To unmount image files in the Finder, just drag the mounted volumes to the trash. To unmount from within the ShrinkWrap application, do the following:
1. Choose the Unmount Image command from the Image menu.
2. Select the disk image volume to unmount using the standard file dialog.
>> Note: Ejecting a mounted image file will only cause it to be automatically “reinserted”. <<
Create Image from Disk - To make an image file of a floppy disks, CD-ROM, hard disk, removable or mounted images, do the following:
1. Choose the Create Image from Disk command from the Image menu.
2. Select the disk to copy using the standard file dialog.
3. If Batch Floppy Mode was enabled in the Preferences dialog, you will be prompted to enter another floppy disk when the first copy is complete. Press Stop when you wish to create no more image files.
Write Image to Disk - To write a disk image file back to disk, do the following:
1. Choose the Write Image to Disk command from the Image menu.
2. Select the image file to copy using the standard file dialog.
3. If Batch Floppy Mode was enabled in the Preferences dialog, you will be prompted to enter another floppy disk when the first copy is complete. Press Stop when you wish to make no more copies.
>> Caution: The unlocked floppy disk that you insert will be totally overwritten with the contents of the image file. For an additional layer of protection, enable the option to confirm overwriting the destination disk in Preferences. <<
Duplicate Disk - To duplicate disks, do the following:
1. Choose the Duplicate Disk command from the Image menu.
2. Select the floppy disk volume to duplicate using the standard file dialog.
3. If Batch Floppy Mode was enabled in the Preferences dialog, you will be prompted to enter another floppy disk when the first copy is complete. Press Stop when you wish to make no more copies.
>> Caution: The unlocked floppy disk that you insert will be totally overwritten with the contents of the image file. For an additional layer of protection, enable the option to confirm overwriting the destination disk in Preferences. <<
Convert Image - To convert any readable disk image file format to the image file format chosen in Preferences, do the following:
1. Choose the Convert Image command from the Image menu.
2. Select the image file to convert using the standard file dialog.
Verify Image - To verify image files and display their 32-bit checksums, do the following:
1. Choose the Verify Image command from the Image menu.
2. Select the image file to verify using the standard file dialog.
>> Note: If the original image file format contained checksums and these match the calculated values, a warning will be displayed in the ShrinkWrap Log. <<
Verify Disk - To verify a volume or mounted image:
1. Choose the Verify Disk command from the Image menu.
2. Select the disk to verify using the standard file dialog.
Scripting Support:
ShrinkWrap supports a custom AppleEvent suite which gives you the ability to control and automate many of the functions within the application. The most common usage of these advanced capabilities is through scripting systems such as AppleScript or UserLand Frontier. In order to facilitate your use of ShrinkWrap with scripting systems, ShrinkWrap includes an 'aete' resource which details the full complement of AppleEvents supported. To examine the 'aete' resource, open Apple's Script Editor, choose Open Dictionary from the File menu and then select the ShrinkWrap application. A gluefile is also provide for scripting with UserLand Frontier.
Important Tips
Do you have enough available RAM?
ShrinkWrap versions 1.2 and later no longer use the MungeImage driver to mount image files. The new driver has two modes, RAM-based and file-based. Basically, when you select the option to “Keep mounted images in RAM” and there is enough free memory available, the driver mounts an image file by creating a RAM disk the size of the floppy, then copying the contents of the image file to the RAM disk. Consequently, to mount an image file in the RAM-based mode, you must always have as much free RAM as disk capacity you wish to mount. (Sorry! Virtual memory doesn't count.)
>> Note: The system heap will expand when memory blocks are allocated to the ShrinkWrap driver to mount disk images in RAM. When you unmount disk images, the corresponding memory is freed. However, the system will not compact and resize the system heap until the free memory is required by another application. So don't be surprised if your system heap doesn't immediately shrink back to its original size. <<
Do you have enough free space on your startup disk?
When the “Keep mounted images in RAM” option is disabled, the driver mounts image files by mapping their blocks directly from the local hard drive or the network server. Unfortunately, there are only three image file types which can be directly mounted in this manner: 'dImg' (ShrinkWrap and DiskCopy 4.2), 'hdvr' (PC Exchange, ShrinkWrap and DropDisk) and 'DDim' (DiskDup+). All other image file types need to be translated to a temporary scratch file which is stored within the invisible Temporary Items folder on your startup disk and then directly mounted with read-only access. Consequently, to mount these other image file formats in the file-based mode, you must have as much free hard drive space as disk capacity you wish to mount.
>> Note: If you should experience a crash when an image file is mounted, any scratch files used for temporary storage of the mounted image will be automatically recovered by the system to the “Rescued items” folder in your Trash. If an image file was mounted unlocked, it may contain checksums that have were never updated to reflect changes you made before the crash. To fix this, disable the “Verify mounted image checksums” option, mount the suspect image file, then drag the mounted volume onto ShrinkWrap. A new image file will be created from the mounted volume that has valid checksums. <<
ShrinkWrap Disk Images vs. DiskCopy:
The ShrinkWrap image file format is identical to the DiskCopy image format except in the following ways:
- ShrinkWrap image files are saved with ShrinkWrap's creator code.
- ShrinkWrap image files don't include the DiskCopy resource that lets you view checksums in the Finder's Get Info dialog.
This may seem trivial, since the actual file format is unchanged, but DiskCopy rather arrogantly refuses to acknowledge the existence of image files created by other applications when you attempt to load them using the “Load Image File...” button or “Load Disk Image...” menu item. (Interestingly enough, DiskCopy will successfully load image files with other creator signatures if they are loaded via drag and drop.)
There are, however, advantages to saving a disk image with ShrinkWrap's creator signature:
- ShrinkWrap image files will be instantly mountable by just double-clicking the image file icon.
- ShrinkWrap image files get a cool new icon with racing stripes in the upper-left hand corner.
- DiskCopy image files will be stuck with a generic icon if a copy of DiskCopy is not located on the destination disk.
- ShrinkWrap image files take up one less allocation block (about 4K on a typical hard drive, 10K on a typical CD).
RAM Doubler:
Connectix RAM Doubler and ShrinkWrap will work fine together provided that there is enough real memory for the images to be mounted in RAM. When real memory gets sparse, most of the smart tricks used by RAM Doubler to increase memory won't work (re-allocating memory, compressing memory blocks, etc.) because there simply isn't any free memory to play with. RAM Doubler then falls back on standard virtual memory and the system will slow to a crawl.
Anti-Viral Utilities:
Some anti-viral utilities may consider ShrinkWrap's activities to be “suspicious” in nature and will stop processing to warn you of some events. If this happens to you, I recommend switching to a less invasive anti-viral utility such as John Norstad's Disinfectant.
Background Compression Utilities:
ShrinkWrap usually can't mount image files that have been compressed with background compression utilities such as StuffIt SpaceSaver, AutoDoubler or More Disk Space unless they are mounted as unlocked disks and kept in RAM.
Hardware Accelerators:
ShrinkWrap will not run with some types of processor accelerators since certain required driver support is not provided. To use ShrinkWrap, first restart with the accelerator disabled.
MFS Disks:
ShrinkWrap is unable to create image files of Mac 400K disks due to restrictions on MFS disks introduced with System 7. All other features, however, are fully supported with disks of this type.
Old Macs:
Some older Macs (Mac 128K, 512K, 512KE & Plus) will be unable to create, verify or copy disk images with ShrinkWrap since their floppy disk drivers do not support the necessary control calls. However, disk image files can still be mounted, converted and verified on these machines.
Contacting the Author
To obtain the most recent release or a beta build of an upcoming release, visit the ShrinkWrap web site at
<http://www.halcyon.com/shrinkwrap/>.
If you would like to suggest a new feature or complain about a bug, contact me via email at
