SheepShaver, what is wrong with your emulation of CD-ROMs?

[CoplAUXX]

I had a physical copy of the Mac OS 8.1 CD-ROM, and I remember that booting from the CD-ROM worked without error messages that only have a "Restart" button on a real Power Macintosh before it loads the Finder, but when I make an image of it and try to use it as the startup disk image in SheepShaver with th Old World ROM, the Mac OS 8.1 on the CD-ROM displays this error message before it loads the Finder:
The system software on the startup disk only functions on the original media, not if copied to another drive.

That error message seemed weird to me. The disk image SheepShaver booted from was an image of the original media, but the Mac OS 8.1 on the image of the CD-ROM is telling me that I must only boot this system software from the original media

I then read some of the answers to other forum discussions about "The system software on the startup disk only functions on the original media, not if copied to another drive." and I found out that a real Power Macintosh would pretend that the Mac OS 8.1 CD-ROM is a locked HFS disk and the Mac OS on the CD-ROM checks if it is booted from a locked or regular HFS disk, and if booted from a regular HFS disk, will display the "The system software on th startup disk only functions on the original media, not if copied to another drive." error message, so I killed the SheepShaver process, changed the primary disk image to the System 7.5.5 disk image I had, and started SheepShaver again. Then I saw that the icon for the emulated Mac OS 8.1 CD-ROM on the desktop in SheepShaver was the icon for a regular HFS disk, not a locked HFS disk.

Now my suggestion for SheepShaver is that, unless "cdimgreadonly false" is in the SheepShaver_prefs, it should emulate images of CD-ROMs as locked HFS disks (just like Mini vMac emulates Disk Copy 4.2 images as locked HFS disks) instead of regular HFS disks.

[Ronald P. Regensburg]

This is not an issue in SheepShaver, it is an intentional feature of the MacOS system on the CD to prevent the use of copies of the system on other media. By making the disk image appear read-only, which can be achieved in different ways depending on the host system, the system can be fooled into 'thinking' it is on the original (read-only) CD. The need to make the CD image read-only is described in the setup guides in our wiki.

I am not sure this can easily be solved in SheepShaver itself. As far as I know, SheepShaver does not discern between CD-ROM images and other disk images that usually should not be read-only.

[adespoton]

This should actually be a pretty easy patch: just have a flag for the images that sets the locked bit if it's enabled... but it's usually just as easy to lock the file.

[Ronald P. Regensburg]

This should actually be a pretty easy patch: just have a flag for the images that sets the locked bit if it's enabled...

You mean a preferences setting? Wouldn't that lock all images, not just the system install CD image? That would make it impossible to install the system, the target volume would be locked also.

[yksoft1]

ResEdit the "System" file and remove the "xboo" resource, then it will stop complaining not running on CD-ROM.