[fpc-pascal]DOS memory access via "absolute"

[Sebastian Schuberth]

Hi there!

Is anyone able to tell me why the following code plots the red pixel but
not the blue one, and why the locking function does not work?

----8<----
Program Test;

Uses
  CRT,GO32;

Var
  Screen:Array[0..199,0..319] Of Byte Absolute $A0000;

Begin
  WriteLn(lock_linear_region($A0000,320*200));

  ReadKey;
  Asm
    mov eax,13h
    int 10h
  End;

  Screen[0,0]:=1; { blue pixel }
  Mem[$A0001]:=12; { red pixel }

  ReadKey;
  Asm
    mov eax,03h
    int 10h
  End;

  WriteLn(unlock_linear_region($A0000,320*200));
End.
----8<----

Thanks in advance!

-- 

Sebastian Schuberth