SWAPUNIT: Swap and Execute Unit
Submitted By:
Unknown
Rating:
Not rated (
Rate It)
Program SwapTest; (* By Kevin A. Kwast *)
{$M 8192,0,0}
(**********************************************************************)
(** This program illustrates a DOS shell spawned from a Pascal **)
(** program. If you have Turbo Debugger or something similar, you **)
(** can examine what is left in memory and notice that the constant **)
(** strings and the Str variable (in data) are NOT in memory. The **)
(** literal strings in the program area WILL be in memory however. **)
(** This is because strings quoted in the code will be placed in the **)
(** code segment. The $M compiler directive specifies a 8192 byte **)
(** stack and no heap. Otherwise, the stack would be at the default **)
(** 16K size, with a heap that will fill all available memory. That **)
(** will mean that the program memory block to be swapped will be a **)
(** very large block (all available memory). Using the $M compiler **)
(** directive allows you to change these default memory usages and **)
(** make more efficient use of memory. If you don't use the heap, **)
(** be sure to set it to 0 so that no heap will be allocated. Just **)
(** for grins, compile this same program using the standard Exec **)
(** procedure and notice the differences! --Kevin **)
(**********************************************************************)
{ Notice that SwapUnit always comes last on the Uses line! }
Uses Dos, SwapUnit;
Const
AnyArray = 'This is a constant string.';
AnotherArray = 'This is another constant string.';
FinalMessage = 'Thank you for trying SWAPUNIT.';
Var
Result: Word;
Str: String;
Begin
WriteLn('This is the swap test (using SwapUnit TPU).');
WriteLn('EMS 4.0 Test Result: ',CheckEMS);
WriteLn('XMS Test Result: ',CheckXMS);
WriteLn('Going to the shell... Type EXIT to return..');
Str:=GetEnv('COMSPEC');
{ For those without the GetEnv function, just use a declaration like: }
{ Str:='C:\COMMAND.COM'; }
Result:=SwapExec(Str,'','SWAP.FIL',SwapToAny);
{ SwapExec is called to execute COMMAND.COM with no command line. This }
{ begins a DOS shell. If swapping to disk is necessary, the swap file }
{ will be called SWAP.FIL; the SwapToAny parameter specifies that all 3 }
{ forms of swapping should be tried. XMS, then EMS, and then Disk. }
WriteLn('Returned from the swap.. Results: High byte = ',Hi(Result),' Low byte = ',Lo(Result));
WriteLn;
WriteLn(FinalMessage);
WriteLn;
End.
