Moving Data using a "Rosetta Stone" Macintosh

As you may have read in my previous article, I have a Power Macintosh 8600 / 200 that is a "Rosetta Stone"  Mac, which I will refer to as a Bridge Mac in this article.  For background about this machine, please refer to the article "My Adventures with Classic Macintosh Hardware - Part 1".

As we left things in that article, the Mac was booting OS 9.1, the last major supported version of Mac OS that will run on that hardware.  Since then, I've discovered through some more careful reading that if I were to get System 7 running, I would have access to more of the original 400K mac floppy disks in the collection.  This was the beginning of my quest to install System 7 on the 8600 / 200.

Being that the computer already has a SCSI2SD adapter, it's quite inexpensive to swap system drives.  Finding a System 7 installer CD that was compatible with the 8600 was more of a challenge.  I tried several disk images before I found one that the computer would boot from.  In the end, the Apple approved System Installation disk for the 8600 and 9600 for Mac OS version 7.6.1 was found here...

The next challenge came because with the SCSI to SD adapter, you cannot easily power off the machine, pull the SD card, and write files to it with the modern Macintosh.  With the SCSI2SD we must find another drive that can be installed in the Mac while it is running either System 7 or Mac OS 9.  I was extremely fortunate because this Mac already has a Zip Drive.

I was able to get a USB Zip drive for my modern mac from my local Free Geek store in Minneapolis, one of my favorite stores!  Once all the hardware was here and in place, I was hoping that I could move files from System 7 directly to my modern Mac in one jump, but the Modern Mac OS (10.14 Mojave) has read only access to "Standard HFS" disks.  So this single jump method will work for migrating files from old too new, but not the other direction.

The more modern HFS Plus file system drives are read write in the Modern Mac, but they seem to work better if you use the old machine to format the drives, then verify access on the modern mac.

There is some information on the Internet about "Puddle Jumping", but it took me some time to realize how to do this.  Although it seems obvious now, I'll cookbook this in a bit more detail in case it will help others.  Here's what I did do to get files transferred From the Modern Mac OS X (Mojave 10.14) machine back to the Bridge Mac running System 7.

Setup Procedure:

1. Start the Bridge Mac in Mac OS 9
2. Format one of the Zip Disks Standard HFS
3. Create these folders on that Zip Disk
   System 7 -> Mac OS 9
   System 7 <- Mac OS 9
   System 7 -> Mac OS X
4. Format another Zip Disk as HFS Plus
5. Created two folders on this Zip Disk:
   Mac OS 9 -> Mac OS X
   Mac OS 9 <- Mac OS X
6. On the Bridge Mac HDD (Mac OS 9 System), create folders to store these files since only one Zip Drive will be plugged in at a time:
   System 7 <- Mac OS X
   Mac OS 9 <- Mac OS X
   Mac OS 9 -> Mac OS X
7. Insert the HFS Plus Disk in the Zip drive attached to the Modern Mac
8. Verify write access to the HFS Plus disk

Now we have the tools in place, we can begin moving files from new too old (the more challenging direction).

1. Prepare all the file data on the Modern Mac computer.
2. Insert the HFS Plus disk into the Zip drive on the Modern Mac
3. Copy the files from the Modern Mac to the folder "Mac OS 9 <- Mac OS X"
4. Eject the Zip Drive from the Modern Mac
5. Start the Bridge Mac using the system drive for OS 9
6. Insert the HFS Plus Zip Drive into the Bridge Mac
7. Copy the files from the Zip folder "Mac OS 9 <- Mac OS X" to the HDD "System 7 <- Mac OS X".
8. Eject the HFS Plus Zip Drive and Insert the HFS Standard Zip Drive.
9. Copy the files from the HDD Folder "System 7 <- Mac OS X" to the folder on the Zip drive called "System 7 <- Mac OS 9"
10. Shutdown the Classic Mac
11. Swap the system drive from OS 9 to System 7 and Restart
12. Move the files from the HFS Standard Drive folder called "System 7 <- Mac OS 9" to the appropriate folders on the System 7 HDD and enjoy access!

I hope these instructions may be of use.  Please leave a comment below if you have suggestions to improve this article, or if you want to share your experiences moving data back and forth off Retro Mac hardware.

Update:

If you only need to use the Bridge Mac to copy data from HFS Standard disks to HFS Plus disks, use Mac OS 8.x. This version allows read and write access to both disk types and can save some hassle.