As part of some research which I’m doing on Mac filesystems, I wanted to see if it was possible to get Apple’s System 1 running on OS X El Capitan. The reason that I am specifically interested in System 1 is that this OS used Apple’s shortest-lived filesystem: Macintosh File System.
After discussing the issue, my colleague @mikeymikey pointed me in the direction of using the Mini vMac emulator application to accomplish this. He also pointed me towards the correct places where I could download a System 1 disk image and the needed Mac ROM file.
With this information, I was able to get System 1 up and running inside of the Mini vMac emulator. For the details, see below the jump.
1. Download Mini vMac, the System 1 disk image, and the Mac ROM file.
2. Uncompress the System 1 disk image and ROM file.
The System 1 disk image and ROM file are compressed using a Stuffit archive format which OS X’s built-in decompression utility is unable to open. I recommend using The Unarchiver to uncompress these files.
3. Put Mini vMac, the System 1 disk image and the ROM file together in one directory.
Note: Having all three in the same directory is necessary so that the ROM file is automatically detected when Mini vMac launches the OS from the System 1 disk image.
4. Launch Mini vMac. By default, no startup disk option is selected so a window will open and display a floppy disk icon with a blinking question mark.
5. To select a startup disk, click on the File menu and select Open Disk Image…
6. Select the System 1 disk image and click the Open button.
7. System 1 should boot within the Mini vMac window.
