[HM] hummmmmm

[Robert Gray]

At 9:12 AM -0800 on 11/8/05, duanemurphy at mac.com wrote:

>--- At Tue, 8 Nov 2005 12:09:38 -0500, Robert Gray wrote:
>
>  >At 3:27 PM +0000 on 11/8/05, duanemurphy at mac.com wrote:
>>
>>>   > On Tue, 8 Nov 2005, michaelP wrote:
>>>>
>>>   >> Can you remind me how to boot from an external hard drive?
>>>   >
>>>>   Hold the option key at boot. A screen will come up that
>>>   > will allow you to select which drive to boot from.
>>>
>>>
>>>   Thanks Allan, I tried this three times and each time
>>>   the screen came up but without the external hard drive
>>>   showing even though it does appear in the Start-Up
>>>   Disk control panel (it has a System Folder identical
>>>   to the one on the internal drive).
>>
>>I'm not so sure you can simple copy the system folder from
>>one drive to another.  Things have to be done; like writing
>>a little sector which tells the system that the drive is
>>bootable.  There may even be invisible files that are
>  >essential and don't get included in a "finder-copy".
>
>While this is true for OS X, OS 9 requires no such tweaking.
>Simply selecting the drive in the Startup Disk control panel
>will fix the drive so that it can boot.


All systems require that there be a disk driver available and
that's not getting written when you drag the folder to the disk.


>This will only work if the System Folder is blessed. A blessed
>System Folder is identified by the Mac OS face on the
>folder....Seeing the Finder file and the System file in the same 
>folder helps the system recognize that this is a System folder.


While that's necessary, it's not sufficient.  There must be a disk 
driver available in order for the OS to be able to read the disk. 
The OS expects that information to be located in the disk boot 
sector.  No driver...no boot, even though there's a blessed folder.

Like I said, try Disk Setup.  It may ask to update the drivers.  If 
that works you're home free.  If not you may have to format/erase the 
drive then drag the system folder again.  See:

http://docs.info.apple.com/article.html?artnum=106849