Cool! This is like... mail or something!
Once upon a time (Sunday, March 16, 1997 to be precise), Brian McCloud wrote 

letter to Nick Coons about "Extra Space."...
 [..]
 NC>>       mov     [es:bx], [di]
 NC>>       ...and
 NC>>       mov     [es:di], [bx]
 NC>> ...it says that I cannot use the segment override.  Is there a way
 NC>> around that?
 BM> first of all, if you're using MASM or a compatible assembler, the 
orrect
 BM> way of doing a segment override is like this:
 BM>         mov     es:[di], [bx]
I'm pretty sure it would accept [es:di].
 BM> second of all, why aren't you doing these as REP MOVSW instructions?
It's slower than moving the data "manually".
But I'm also pretty sure that's not the problem :). It seems as if Nick has
previously programmed on an Amiga or a similar machine where memory-to-memory
operations are supported. That's not the case on the PC. You _need_ to move
the data through a register. Yes, the 80x86 has got to be the most worthless
piece of silicone the world has ever seen :-\.
   ("`-/")_.-'"``-._
    O O `; -._   )-;-,_`)
  =(_~_)=  _  )`-.\  ``-'   - Flemming Sondergaard
   _.-~_..-_/ / ((,'
 ((,.-'   ((,/
--- Terminate 4.00/Pro
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