Disks & Disk Images
Sweet16 uses disk images to contain the files and other data used by the emulated Apple IIgs. A disk image is a file that contains a copy of an entire disk, be it a hard disk or a floppy disk. This image file is then used by the emulator to simulate access to an entire disk.
Mounted Disks Window

Each disk is shown with a representative icon next to it. The disk activity indicator lights in green on SmartPort and IWM 3.5" disks (both represented by the 3.5" disk icon) when active, and the red lamp on 5.25" disk drives lights when those disks are accessed.
Next to each item in this list is the name of the image file (or physical disk device), and below that is the device number, disk image type, and disk size. You can eject disks by right-clicking one and choosing Eject from the popup menu that appears.
Disks that are locked, or are read-only, have a lock icon in the lower-right corner of the disk drive image.
Disks with device numbers from 1 to 12 are SmartPort devices. Device numbers 13 and 14 are 3.5" IWM images. Devices 15 and 16 are 5.25" images.
Getting Files from Mac OS X into Sweet16
Sweet16 supports several disk image formats that are also supported by Mac OS X (note that this isn’t as easy as it should be on Mac OS X 10.6 “Snow Leopard” due to it no longer supporting writing to HFS disk images); in particular, the DiskCopy 6 disk image format is the most commonly-used image format on Mac OS X. This is really useful when you're transferring files to and from Sweet16 from Mac OS X. Here's how it works.
You can create a disk image that you can use from both the Mac and the emulated Apple IIgs using either the Disk Copy utility (choose the "read/write" image format) or by using the Create Disk Image option inside Sweet16. In either case, you should format the disk image using HFS (also known as Macintosh standard) format. Don't use HFS+ (Macintosh enhanced) format, which the IIgs can't read. This tends to work best when you format the image using the emulated Apple IIgs.
Don't forget that to format and use HFS disks on the emulated IIgs, you need to be sure the HFS.FST is installed in the System/FSTs folder on your IIgs boot disk. You can find it in the System/FSTs folder on the SystemTools1 System 6 or 6.0.1 floppy.
Once you have the disk image, you can mount it on the Macintosh by simply double-clicking the image file in the Finder. At this point, you can copy files on and off the image, use them in applications, and so forth.
When you're done using the image on the Mac, simply eject it like any other disk.
This is very important. Don't have the same image mounted on both Sweet16 and Mac OS X at the same time, or corruption will almost certainly occur.
Creating a Disk Image
If you need to create a new disk image, choose the Create Disk Image option in the File menu. A save panel will appear, with two extra menus. The first, Format, lets you choose the disk image format to save in. The second, Image Size, lets you pick a size for the disk image you want to create.
Choose where you'd like to save the new disk image, the type and size of the image, then type the name of the image file.
Sweet16 uses file extensions to tag disk image files as to what type of image they are, so you should include the appropriate file extension so the file can be identified properly:
Device | Image Format | File Extension | Image File Size |
---|---|---|---|
3.5" disk | DiskCopy 4.1/4.2 | .img | 800KB |
DiskCopy 6 | .dmg | 800KB | |
Hard drive | .hdv | 800KB | |
Raw data | .raw | 800KB | |
Universal Disk Image | .2mg | 800KB |
Device | Image Format | File Extension | Image File Size |
---|---|---|---|
5.25" disk | DSK | .dsk | 140KB |
DOS 3.3 order | .do | 140KB | |
ProDOS order | .po | 140KB |
Device | Image Format | File Extension | Image File Size |
---|---|---|---|
Hard disk | DiskCopy 6 | .dmg | any (other than 800 KB) |
Hard drive | .hdv | any (other than 800KB) | |
Raw data | .raw | any (other than 800KB) | |
Universal Disk Image | .2mg | any (other than 800KB) |
Once you've created the disk image, it will automatically mount on the emulated IIgs. Sweet16 has already formatted the image as a ProDOS disk, but you can erase it to another format if you want to using the Erase Disk option in the Apple IIgs Finder.
Mounting Disk Images
Once you have a disk image that you'd like to mount (whether it's one you created yourself using Sweet16 or downloaded from a web site), there are two ways you can mount it:
- Choose the Mount Image option in the Sweet16 File menu, then locate and open the disk image file. You can mount multiple images at once by selecting them all.
- Drag a disk image file into the Sweet16 video or Mounted Disks window.
800KB images are, by default, mounted in one of the two IWM 3.5" devices. You can override this behavior by holding down the option key while mounting them; this causes them to be mounted as CleverPort devices instead. This can be really useful, especially if you're installing System 6.0.1, which is six disk images, or playing a game that's on multiple disks (like Space Ace).
In addition, you can configure Sweet16 to default to mounting 3.5” disks on the CleverPort instead of on the IWM. This is done in the Storage panel in the Preferences window.
140KB floppy images (.dsk, .do, and .po formats) are always mounted in one of the two IWM 5.25" devices. Everything else is mounted in one of the eight CleverPort devices; these devices emulate the SmartPort protocol for disk accesses. When you do this, you need to also mount the disk on the IIgs, since it doesn't necessarily automatically mount 5.25" floppies. To do this, double-click the .APPLEDISK5.25A or .APPLEDISK5.25B icon in Finder that corresponds to the disk you want to mount.
If you have a 140KB disk image in DiskCopy 6 or raw format, the image will be mounted on the CleverPort. These are different from standard 5.25" drives, but work fine. A new 5.25" drive icon will appear on your desktop. Double-click that to mount the floppy on the IIgs.
When mounting 800K disk images, you can hold down the option key to ask Sweet16 to mount them as CleverPort devices instead of as IWM 3.5" disks. This lets you mount lots of 3.5" disk images at a time, which makes installing system software really quick and easy.
Automatically Mounting Images
Usually you'll have disks that you want to have online when you first launch Sweet16 (such as your boot disk). Sweet16 will automatically mount any disk image files in your Library/Application Support/Sweet16/Disk Images directory when you launch Sweet16. Images are mounted into appropriate devices. The first device on the slot your IIgs control panel is configured to boot from will be your boot disk.
Slot 5 will contain your IWM 3.5" disks, Slot 6 contains the IWM 5.25" disks, and Slot 7 contains your CleverPort disks.
Disk images are mounted in alphabetical order, so you should make sure your boot disk is the first image, alphabetically, in the Sweet16 folder.
Using CD-ROMs
Sweet16 allows you to mount CD-ROM media into your emulated Apple IIgs. Simply select the Mount CD-ROM option from the File menu, and Sweet16 will attempt to mount up to nine partitions from your CD media on the emulated Apple IIgs. This will work with any file systems supported by the Apple IIgs, including ProDOS, HFS, and ISO 9660 (High Sierra) (assuming of course you have the correct FSTs installed).
When you eject the last partition from the CD-ROM, the disc will be physically ejected from your Macintosh.