TMPLee@DOCKMASTER.ARPA (02/13/89)
In response to my question about write-protection o fhard drives someone pointed out the protection bits in ProDos. I'm afraid that without any address protection hardware they are useless -- any virus writer worth his salt would do direct block reads and writes, ignoring all of ProDos, which is why I was asking about a physical switch you could throw.
scott@claris.com (Scott Lindsey) (02/13/89)
From article <890213043846.812082@DOCKMASTER.ARPA>, by TMPLee@DOCKMASTER.ARPA: > In response to my question about write-protection o fhard drives someone > pointed out the protection bits in ProDos. I'm afraid that without any > address protection hardware they are useless -- any virus writer worth > his salt would do direct block reads and writes, ignoring all of ProDos, > which is why I was asking about a physical switch you could throw. It's going to be dependant on your particular hard drive & interface card. I've got a 60Mb CMS and there are jumpers on the SCSI card that you can set (but this means powering down, pulling the card, etc. I was experimenting with this when I was trying to have more than one GS connected to the hard drive at a time (I wanted the boot volume to be write-protected so it wouldn't messed up by having more than one instance of GS/OS accessing it at a time. Unfortunately, there's a bug in GS/OS where it returns the Disk-is- write-protected as an error instead of a status during the boot sequence. This was the case with a pre-release version of GS/OS; I haven't tried it with the final version, but I was given the impression by Apple that it wouldn't be fixed. It's not exactly something that would be a common problem. I don't know if the problem lies with write-protected hard-drives in general or just those that use a generated driver. -- Scott Lindsey, wombat | UUCP: {ames,apple,portal,sun,voder}!claris!scott Product Development | Internet: scott@claris.com | AppleLink: LINDSEY1 Claris Corp. | Disclaimer: These are not the opinions of Claris, (415) 960-4070 | Apple, the author, or anyone else living or dead.
labc-3dc@web-3c.berkeley.edu (Andy McFadden) (02/14/89)
In article <890213043846.812082@DOCKMASTER.ARPA> TMPLee@DOCKMASTER.ARPA writes: >In response to my question about write-protection o fhard drives someone >pointed out the protection bits in ProDos. I'm afraid that without any >address protection hardware they are useless -- any virus writer worth >his salt would do direct block reads and writes, ignoring all of ProDos, >which is why I was asking about a physical switch you could throw. The point was, you could to some degree prevent viruses from attaching themselves to your files. Issuing ProDOS WRITE commands for a file is *much* easier than writing the block, updating the system bit map, updating the file's block list, updating the EOF, etc, etc... The problem is, it can't prevent a virus from wiping out the drive (as you point out) by doing direct block reads and writes. There really can't be a convenient way to do this unless HD manufacturers begin mounting switches on the external portion. What IS conceivably possible is to have two different copies of the ROMs, only one of which (read/write, write only) is selectable at a time. This shouldn't be all that hard to do, assuming you are willing to risk your drive in the interests of experimentation... -- labc-3dc@widow.berkeley.edu (Andy McFadden)