May 132013


This weekend I spent some time attempting to diagnose the symptoms plaguing several of my Classic Macs. One Color Classic refused to start up, displaying the blinking question mark when booted, indicating it could find no operating system. When booted from a Disk Tools floppy disk Disk First Aid saw no hard drive to check, while Drive Setup did see an internal hard drive and tested it successfully, but could not mount it. I decided it was time to boot from a Norton Utilities Emergency Disk and see if it could mount the problematic disk and make the needed repairs.

Although I have at least a dozen Norton Utilities Emergency Disks I could not locate the one needed for this Mac, so I hunted down an image and then spent a couple of hours trying to create a bootable floppy disk from it. That task was not nearly as simple as it sounds, since the disks and drives involved are over a decade old and therefore suspect, and Mountain Lion won’t run Classic apps like Disk Copy. I finally got a disk created on another Color Classic only to find it was unreadable on the one I was working on.

I could have saved myself a LOT of time if I had consulted Low End Mac first and read Creating Classic Mac Boot Floppies in OS X  from 2008 by Paul Brierley that describes how to use an external floppy drive and the Terminal application on a modern Mac to create a floppy disk from an image. I attached my blueberry colored VST external floppy drive via USB cable to my MacBook Pro running Mountain Lion, followed his simple steps, and in about two minutes had a perfectly functional Norton Utilities Emergency Disk to start up the Color Classic.



  One Response to “Making a rescue floppy disk on a modern Mac”

  1. A couple additional tips about this:
    1. If you get a permissions error when you run the command in terminal, try prefacing the command with sudo, e.g. sudo dd if=~/Norton_Emergency_Disk.image of=/dev/disk1 bs=84 skip=1 then enter your admin password when prompted.

    2. When I tried to use this command on a blank floppy disk that was formatted as a PC/DOS disk I usually encountered a “resource busy” error. Erasing the disk and formatting it as a MacOS disk then trying again resolved the error.