question about mov

lemm · Post by **lemm** » Thu Aug 27, 2009 2:49 am

How do I get the opcodes for:

mov ax, cs:[35FBh]

and

mov cs:[35FBh], ax

I am writing a patch and I want to manipulate the word at 35FB.

Could I Push DS and then load CS into DS?

CommanderSpleen · Post by **CommanderSpleen** » Thu Aug 27, 2009 3:24 am

I don't know enough to be of service here. But if you study a disassembly of a Keen executable, you're bound to find some examples of it.

lemm · Post by **lemm** » Thu Aug 27, 2009 5:57 am

Got my question answered.

Prefixing mov with $2E means use CS (instead of DS, in this case)
However, this only works for one instruction, so I will just pop/push because I want to use the CS multiple times.

CommanderSpleen · Post by **CommanderSpleen** » Thu Aug 27, 2009 6:48 am

Do post the code when you've got it figured. Would be useful to have here for future reference.

lemm · Post by **lemm** » Thu Aug 27, 2009 7:37 am

YES!!!

Just finished the jetpack patch... posting shortly.