A: ParamCount and 
ParamStr are for parsed parts of the command line
and cannot be used to get the command line exactly as it was. 
See
what happens if you try to capture
  "Hello.   I'm here"
you'll end up with a false number of blanks. For obtaining the
command line unaltered use
  type CommandLineType = string[127];
  var  CommandLinePtr  : ^CommandLineType;
  begin
    CommandLinePtr := Ptr(PrefixSeg, $80);
    writeln (CommandLinePtr^);
  end;
A warning. If you want to get this correct (the same goes for TP's
own ParamStr and ParamCount) apply them early in your 
program. At
least they must be used before any disk I/O takes place!
:
A related example demonstrating a function giving the number of
characters on the command line
  function CMDNBRFN : byte;
  var paramPtr : ^byte;
  begin
    paramPtr := Ptr (PrefixSeg, $80);
    cmdnbrfn := paramPtr^
  end;  (* cmdnbrfn *)
For the contents of the Program Segment Prefix (PSP) see 
Tischer,
Michael (1992), PC Intern System Programming, p. 753.