title: Uninitialized variables using NASM
body: <p>I have built a sbc using a 80c188 processor ( 128kb ROM, 512kb RAM ). 
  I have used NASM to compile the boot program with  some 'flakey' results.
  My question is this:-
    since the programme is run from ROM  how can any Uninitialized variables work?  Whether or not a '.bss' section is declared within the file, the variables don't work as expected. ( this will probably seem obvious to most!)
   I assume they must be pointed to an area in RAM in order to work.
  But I do't understand the mechanism to do this.
  Bear in mind, there is no OS on board, this what I am trying to create.
  Any help would stop me going nuts.</p>