You need to use the 3 addresses, and it's a 3-part nop. So it would look like this:
Code:
Call WriteAByte(&H51DF96, 144)
Call WriteAByte(&H51DF97, 144)
Call WriteAByte(&H51DF98, 144)
Call WriteAByte(&H51DFA7, 144)
Call WriteAByte(&H51DFA8, 144)
Call WriteAByte(&H51DFA9, 144)
Call WriteAByte(&H51DFAD, 144)
Call WriteAByte(&H51DFAE, 144)
Call WriteAByte(&H51DFAF, 144)
For each time you write the address, you have to go up by one letter or number, this is very important.
These addresses might be old though.