Accessing a specific memory address

madtown55 · #1 16-Mar-2005, 08:13

I am attempting to read and write to a specific memory location. My first attempt was as follows:

CPP / C++ / C Code:

int main(int argc, char *argv[]) { 
int *num1; 
void *p; 
p = reinterpret_cast< void* > (0x04e27e74); 
num1 = (int*)p; 
printf("0x4e27e74=0x%x\n", *num1); 
return 0; 
}

but every time I run the code to see what is in the memory location I get an access violation exception. I though of using MK_FP, but I do not know what the segment address of this memory address is or how to figure it out.

Basically the above code segment is what I want to do, except I also want to write to the specific location, but it does not work. All sugestions are welcomed.

Madtown54

davekw7x · #2 16-Mar-2005, 08:32

Quote:

Originally Posted by madtown55

I am attempting to read and write to a specific memory location.
but every time I run the code to see what is in the memory location I get an access violation exception.

Madtown54

"Modern" operating systems (any Windows > 98/ME, Linux, BSD, etc.) will not allow user programs to have direct access to hardware resources (memory, i/o devices, etc.)

Regards,

Dave

madtown55 · #3 16-Mar-2005, 08:41

Thanks for your response Dave. How would you suggest I best accomplish what I am trying to do then?

davekw7x · #4 16-Mar-2005, 12:37

Quote:

Originally Posted by madtown55

Thanks for your response Dave. How would you suggest I best accomplish what I am trying to do then?

Learn about device drivers (Microsoft DDK is a place to start. Lots of books.)

Regards,

Dave

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