Re: Converting an external hard drive enclosure into a write blocker?

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The easiest thing to do is to use a bridge whose firmware can be  
modified to take a different action upon the issuance of a write (or  
write-related) command.  Operating systems will react differently  
depending upon whether the device returns an error code, success code,  
or remains quiet.  The bottom line is that you need to intercept  
packetized commands - write enable is not based off of a pin pulled  
high or low. For more information, check out the ATA/ATAPI5 documents  
from the T13 working group.

- Matt


On Nov 20, 2007, at 11:11 AM, Terry Roebuck wrote:

> A*nix mount with DD would be my option of choice, but for windows, I  
> hesitatingly ask could you not modify an IDE cable to make any  
> connected drive 'read-only' (might require a resistor - not sure if  
> you can just clip a wire? - maybe some one with better EE skills  
> could answer that?)


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