Setting up your vintage (classic) 68k Macintosh – Creating your own boot-able disk image

With SCSI being essentially obsolete, and the fact that Macintosh systems (since OS X 10.6 I think) can no longer write to HFS formatted disks, the best way to use modern systems when setting up your classic 68k system is to use disk images and a Macintosh 68k or PowerPC emulator.

Disk images are essentially binary (bit for bit) copies of the contents of a storage device or medium such as your Hard Drive, removable drive, memory card or CD-ROM (ISO files).  There are several types of disk images you’ll come across working with 68k systems:

  • Disk Copy 4.2 images, typically of floppy disks.   These were created by Disk Copy 4.2 a program provide by Apple, and were the most common images for sharing Macintosh software.   Now under emulation they are less popular, but they can be converted to standard “raw” disk images
  • Raw Disk Images of Floppy disks: contain a binary copy of a floppy disk.  The file size is the same size in bytes as the maximum amount that can be stored on the disk, e.g. 400k, 800k or 1440k.  These images can be used with Floppy-Emu.
  • A Partition Image: contain a binary copy of a single partition from a hard drive or removable drive.  When emulators refer to a hard drive file, a Partition Image is typically what they are actually referring to and support.
  • A Hard Drive or Removable Drive Image : contain a binary copy of the complete contents of an initialized drive including the drive’s boot and partition information.   vMac can NOT read these files, Basilisk II can read and update the the first partition of these files, but not initialize them (partition them).   The only Macintosh 68k emulator I’ve found so far that can actually initialize and partition a full disk image is SoftMac by Emulators Inc.

I use Hard Drive or Removable Drive Images to back up my old scsi drives and to setup from both real and emulated (e.g. SCSI2SD) drives.

This blog entry covers:

  1. reasons for using disk images,
  2. images I’ve created for you to use,
  3. how to create your own images,
  4. initializing your own images,
  5. modifying the contents of disk images (mine or yours), and
  6. writing an Image back to a real or emulated (memory card) hard drive or removable drive (e.g. zip disk)

Reasons for using disk images

There are typically three main reasons for creating a disk image:

  1. I want to backup an existing hard drive or removable drive’s contents that I’ve managed to connect to a modern system (see options 6 to 8 from my blog entry for Setting up your vintage (classic) 68k Macintosh for a list of connection methods)
  2. I want to create an image from an existing hard drive, removable drive, or memory card so I can:
    • initialize and format the image (SoftMac by Emulators Inc is the only 68k emulator I’ve found that let’s me initialize an image)
    • copy the System Folder and / or other files to the image
    • write the image back to the physical drive / memory card
  3. I want to image an existing hard drive, removable drive, or memory card’s contents so I can edit the contents of the image then write the image back to the drive or card

Using one of the disk images I’ve already created

As I have time I’ve been creating basic initialized and boot-able images for the different removable drives or modern replacements that I own, and blog entries explain any specific details for how to use the drive the images were created from, note the image files are compressed, and are typically under 10MB in size to download:

Drive / Device System 6.0.8 System 7.5.5
CDROM Soon Soon
FloppyEMU Soon Soon
Iomega Zip Drive 100MB 100MB
Iomega Jazz Drive Soon Soon
SCSI2SD 4GB, 8GB, 16GB, 32GB* 4GB, 8GB, 16GB, 32GB*

* 32GB disk images have been configured as 2 emulated drives, see the full blog entry for how to configure your SCSI2SD adapter when using these images.

Each image contains:

  • The system folders for both System 6.0.8 and System 7.5.5, containing the “minimal” files to boot, with only one of them “blessed” to be the startup system
  • The minimum boot files in the system folder to boot
  • A patched version of HD SC Setup 7.3.5 for formatting your SCSI HD or equivalent once you’ve booted your Macintosh (patched to support non-Apple SCSI Drives)
  • Disk Copy 4.2 by Steve Christensen (for Apple) for creating image files from floppy disks, or writing images back to floppy disks
  • StuffIt Expander 5.5 (freeware, installed and installer) by Aladdin Systems, for opening StuffIt and other archive files (.arc, .bzip, .bin, .cpt, .dd, .gz, .hqx, .lha, .img, .lhz, .pkg, .sea, .sit, .smi, .tar,  taz, .uu, .Z, .zip)
  • ShrinkWrap Version 2.1 (last release before becoming an Aladdin product) by Chad Magendanz, for creating files that you can mount that emulate a floppy disk or hard disk.  I use this program to create 32MB ProDos image files that I can use to transport and backup the contents of my ProDos partitions I use with my Apple IIe card.
  • DropDisk by Mike Wiese and Chris Cotton that allows you to quickly mount and use disk images created with Disk Copy or ShrinkWrap
  • System Picker by Kevin Aitken that allows you to select which System Folder is active (blessed) on restart.
  • If the image size is greater than 512MB, there is a a single 512MB Partition, the rest of the disk(s) are not partitioned and are uninitialized so you can set them up how you want.

Once you’ve downloaded the correct image for your drive or device, scroll down to the section for writing a disk image to your device.

Creating your own disk images

Disk Duplicator (DD) is a standard application that can be used for imaging disk drives, memory cards, usb keys, and CD ROMs.   This guide is written for DD, an application included with Macintosh OS X, and Linux, but not with MS Windows.   For MS Windows you can download version 0.6beta3 created by John Newbigin.

If I don’t want to use DD, any application that creates “raw” disk images can be used, on MS Windows, I often use a program called the USB Image Tool by Alexander Beug, specifically version 1.72 (for some reason the latest version did not work for me), to create and write the image files for my iomega Zip Disks (I have a SCSI and a USB version of the drive), or memory cards attached to my modern system via USB

The steps if I’m using DD to create the disk image:

  1. If I’m using windows, download dd for windows
  2. I attach or insert the hard drive, removable drive (Zip Drive, Jazz Disk etc), memory card (SD, Compact Flash etc.) that I want to image (see options 6 to 8 from my blog entry for Setting up your vintage (classic) 68k Macintosh for a list of connection methods)
  3. open the terminal / command line window
  4. Type dd --list (windows), diskutil list (linux and mac OS) and press return
  5. You should see a list of all attached drives for your system with their names, you should see the name or your micro SD, SD or CF card, you want the identifier of the floppy drive eg. /disk2
  6. Use dd with the correct input and output options, “dd if=INPUTFILE of=OUTPUTFILE”:
    • INPUTFILE = /dev/{identifier from step 5}, e.g. /dev/disk2
    • OUTPUTFILE =  the location and name of the image you would like to create.
    • e.g. Type “sudo dd if=/dev/disk2 of=OS_755_4GB-SD.img”.
    • press return
    • wait…. if you’ve connected via USB 1 or USB 2, this could take some time for larger drives

Using SoftMac to initialize the disk image

If you plan is to write back the disk image to a real or emulated drive, and then boot your 68k Macintosh from that drive, the image will have to be initialized and have the minimum boot files on the drive.   Most emulators can not do this, they do not treat disk images as actual drives, instead they treat them as partitions, when these “partition” images are written back to you real or emulated drive they will not boot.

At this time, the only emulator that I’ve fouudn

If you created your own disk image from a real or emulated drive that hasn’t already been initialized you can initialize that image so that when you write it back to your real or emulated drive it will actually boot your 68k Macintosh system (and some PPC systems).  Unfortunately this solution is currently limited to Windows systems that can run SoftMac (perhaps Linux with WINE, not sure).  SoftMac is the only emulator I found that treats disk images as actually physical disks.   Most emulators only treat the image as a partition.

  1. Download and install SoftMac (see E-maculation’s guide)
  2. Under SoftMac, mount both:
    1. the disk image you just created
    2. a bootable disk images that has the patched version of HD SC Setup 7.3.5 for initializing the image (you can use one of mine, see above)
  3. Initialize and partition your disk image using HD SC Setup 7.3.5.

Copying files to you disk image

Once you either downloaded one of the disk images I’ve created, or created your own, you’re probably going to want add files to the image before you write the image back to your drive, disk or memory card.

Many tools for copying files to and from disk images will NOT work with the image file you just created.

  • Will NOT work: HFVExplorer, Mini vMac
  • Will work: SoftMac, Basilisk II (will read/write to the first partition, ignores the rest)

Writing your or my disk image to your drive, disk or memory card.

Please be careful when running the following commands, if you accidentally “write” the image to the wrong disk you will overwrite data on that disk:

  1. Open the terminal / command line window
  2. Type dd --list (windows), diskutil list (linux and mac OS) and press return
  3. You should see a list of all attached drives for your system, with their names, you should see the name or your micro SD, SD or CF card, you want the identifier of the floppy drive eg. /disk2
  4. For linux and mac OS: type diskutil unmountDisk /dev/{identifier from step 4}, e.g.  diskutil unmountDisk /dev/disk2 and press return
  5. You should see a message: “Unmount of all volumes on {identifier from step 4} was successful”,
  6. The micro SD, SD or CF drive icon should disappear from your desktop (if it did not you may not have the correct device name, check to see if any of your other drives have stopped working) (I say should, because I’m unsure of this step, I believe unmounting the drive should cause it’s icon to disappear)
  7. Use dd with the correct input and output options (read points below), “sudo dd if=INPUTFILE of=OUTPUTFILE
    • INPUTFILE = the location and name of the image you downloaded or created, you can optionally type “dd if=” then drag the disk image file on to the terminal server, this “should” insert the text you need for the input file.
    • OUTPUTFILE =  /dev/{identifier from step 4}, e.g. /dev/disk2
    • e.g. Type “sudo dd if=OS_755_4GB-SD.img of=/dev/disk2”.
    • press return
  8. When your Modern Macintosh is done writing the image, exit the terminal window and remove your card (or USB adaptor and card)
  9. Insert your your SD, microSD or CF Card in to your SCSI adapter
  10. Turn on your Classic 68k Macintosh and it should boot


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