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Index > Main > Writing a 2-byte value into [ffff]

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l4m2



Joined: 15 Jan 2015
Posts: 657
l4m2
I used Proteus to run it:(you should turn it into real code if you want to try it
Code:
mov [f001:ffff], ffff  ;[0000F]=[00010]=FF
mov [f000:ffff], ffff  ;halt
mov [0000:ffff], ffff  ;[0FFFF]=[10000]=FF    

(not sure whether it stimulates right as a real one)
But for a newer cpu, it causes a #GP (right?) which will be regarded as IRQ5. after IRET the running will go into a mess.
Are what i said right?
Post 17 Oct 2015, 11:14
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revolution
When all else fails, read the source


Joined: 24 Aug 2004
Posts: 17716
Location: In your JS exploiting you and your system
revolution
You didn't supply enough information to answer your question.

What mode is the CPU in?

What are the values of the segment register shadow registers?

What is in the paging tables?

Is the A20 gate enabled?
Post 17 Oct 2015, 13:24
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l4m2



Joined: 15 Jan 2015
Posts: 657
l4m2
8086 in proteus
Post 19 Oct 2015, 15:14
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