I need to know something simple.  Yeah, right you say?  Ok, here it is:

What is meant by the first line of:

       3d4h index 33h (R/W): Extended start ET4000  (ET4000 Only)
       bit 0-1  Display start adress bits 16-17
           2-3  Cursor start adress bits 16-17
                Can be used to ID ET4000

What does 3d4h index 33h mean?  How do I read and write this register?
I'm doing something very simple.  I'm converting a document I found
called 'tseng.doc' to a program to read the registers that it is 
describing.  For the above register, the program would come back and
say what the current settings of 3d4h index 33h are.  From there I'm
going to start hacking on the thing.

Could someone help get me started?

Thanks,
David Willmore
willmore@iastate.edu