{********** main program loop **********}
procedure main_menue;
begin
  timeout;
  if first then begin
    default;
    eraseOK:= false;
    if length(line)= 0 then line:= 'C'; {call}
    if carrier then line:= '';
    first:= false;
  end;
  if (length(line)= 0) and not command_file then begin
    if eraseOK then resetCRT;
    eraseOK:= true;
    write('        Main Menue ');
    if carrier then writeln('(carrier)') else writeln('(no carrier)');
    writeln;
      if not carrier then begin
        writeln('(C)all                    (H)ost mode');
        writeln('(T)erminal mode           (D)efaults');
        writeln('(W)ait                    (Q)uit');
      end
      else begin {carrier}
        writeln('(T)erminal mode                (W)ait');
        writeln('(S)end a file (XMODEM)         (D)efaults');
        writeln('  (SA) ASCII text              (X) Disconnect');
        writeln('(R)eceive a file (XMODEM)      (Q)uit');
        writeln('  (RC) Checksum  (RX) CRC');
      end;
      writeln;
      write('Enter SELECTION: ');
      readln(line);
  end;
end; {main_menu}

procedure action;
begin
  if command_file then next_command;
  if length(line)= 0 then line:= 'Y';
  case upCase(line[1]) of
     'C': begin
            if eraseOK then clrScr;
            call;
          end;
     'T': begin
            if eraseOK then clrScr;
            terminal_mode;
          end;
     'K': port[StatusPort]:= $35;  {command byte}
     {*** remember 'timein' if disk access ***}
     'S': send_a_file;
     'R': receive_a_file;
     'A': send_ascii;
     'H': begin
            if eraseOK then clrScr;
            host;
          end;
     'W': do_wait;
     'D': default;
     'X': begin
            if eraseOK then clrScr;
            eraseOK:= false;
            disconnect;
          end;
     'Q': timein;
  end;
  if line[1] in ['Q', 'q'] then line:= 'Q' else line:= '';
end; {action}

{********** program starts here **********}
begin
   line:= getTail; {CP/M command tail}
   first:= true;
   clrScr;
   writeln(^I^I + 'P M O D E M  v1.1a communications program');
   writeln;
   repeat
   {this is the main program loop}
     main_menue;
     action;
   until line= 'Q';
   writeln;
   disconnect;
   writeln('++ Return to System ++');
end. {program}