Using disk images for learning games?

Question

Hello, I've 2 g3 imacs running 9.2.2, and they are for the grandkids to use learning games on.
The kids are very hard on the software disks. When I found out about disk images I made them up, now to install them properly. The games are installed, but where to store the disk images? The desk top icons for the games will work after the disk images have been double clicked and the mounted disk image appears on the desktop, but when the imacs are turned off the mounted disk image is lost. How or where does one put the disk images in a safe place so the kids don't get at them, and the disks are mounted every time, without actually starting, when the Mac is started? Start up menu?
I'm planning on multiple accounts with them having a standard account with game privileges so they don't mess the whole thing up. If their accounts get too messed up for me to repair I figured on maybe deleting the account and opening up a new one? Any Ideas are very welcome.
Thank you,
EZ

Answer 1

Hi, EZ -
You're quite welcome.
I had a thought with regard to the disk image files. Are they in a .smi format, or are they in a .img format?
The .img format requires the assistance of the Disk Copy utility in order to mount the image. This is the standard format generated by the user version of Disk Copy. It requires that Disk Copy be available to Finder to act as a helper app in order to mount the image.
The .smi format does not - .smi stands for Self-Mounting Image. The user version of Disk Copy can not make this format; but I have seen a utility to convert .img format to .smi format. The slight advantage with this format is that Disk Copy does not need to be available to Finder.
In both cases the default is to run a checksum verification before the image is finally mounted. The delay caused by this verification can be inconvenient - verification is intended to confirm the integrity of the image after it has been copied, transported, or downloaded, but is usually not necessary when the image resides on a hard drive.
The checksum verification for .img file types can be removed. With the image not mounted, open Disk Copy. In Disk Copy's Preferences (Edit menu), uncheck the Verify Checksum item. Save the Preferences window. Then select Convert Image from the Image menu, navigate to the disk imge file from which you want to remove the verifiaction, select it and click the Open button. A new window will appear, similar to a Save As type window. Leave everything in that window untouched (unless you want to change the base name of the file - the extension .img should be left intact) and click the Save button. The image will be mounted, the original disk image file will be deleted, and a new disk image file created. Unfortunately creating the new image file takes quite a while since it is creating a new one, not actually modifying the old one - but it does get rid of the intrusion of the checksum verification requirement.
I verified on my G4/500 running OS 9.1 that a .img file (one I had made from a game CD years ago) dropped into the Startup Items folder will be mounted automatically at the end of the startup sequence. I also tested with an alias to the .img file, and it, too, worked fine - the disk image was mounted automatically at the conclusion of the startup sequence.
When you make the alias to the disk image file (the .img one), be sure you are placing it into the Startup Items folder, and not the Startup Items (disabled) folder.
If you have the machine set to use Simple Finder (which removes Finder's keyboard commands and many menu options for Finder), that may interfere with items in the Startup Items folder being run at startup. Or, it may not - I have not checked that.
*** Edit ***
I have verified that the alias to a .img file will mount the disk image even when the machine is booted using Simple Finder.
Another thought, related to Multiple Users - if you do decide to set up Multiple Users, and the disk images are of type .img, be sure to authorize Disk Copy for each of the accounts for which the disk images are to be mounted. If you have the disk image files in a .smi format, since Finder views that file type as being an application, you would need to authorize each of those disk image files for each account which is to have access to them.