[Coco] OS-9 terminology

Allen Huffman alsplace at pobox.com
Fri Aug 20 23:59:31 EDT 2004


> Would this prevent virus infestation of OS-9?

Somewhat, since any modification of a module on disk would invalidate 
the CRC and the OS would refuse to load it.  This prevents loading 
intentionally or accidentally damaged modules.

BUT, there are commands that fix the CRC, so you can update it after 
disk editing it, so a clever "virus" could do that easily.

More important is the CRC number on each module.  If you know what the 
CRC is supposed to be, any change can be detected.  So, a virus scanner 
could simply go through a disk structure and catalog all the CRCs, 
comparing against known values, or reporting things that have changed 
since the last scan.

Any virus running as a true OS process would show up in the process 
display (which DOS didn't have) but someone could prolly write a hack 
that patches in somehow behind the OS.  Without memory protection 
(which the 6809 does not provide, but PowerPC, 68K, etc. do) any type 
of corruption could be done.

But it is harder under OS-9.

		A




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