{*-------------------------------------------------------------------
 * Sample program for the IDI-48 demonstrating register level access
 * of input data
 *------------------------------------------------------------------*}

Uses
    Crt;

Const
   ofs   : Array[0..5] of Byte = ( 0,1,2,4,5,6 );

Var
   Address : word;
   Prt   : Byte;
   Input : Byte;
   Data  : Byte;
   Mask  : Byte;
   S     : String;
   C     : Char;
   i     : Integer;
   Valid : Boolean;
   Done  : Boolean;


Function Deci(DS : String) : Word;
var
   BS : String;
   Er : Integer;
   DI : Word;
begin
   BS := '$' + DS;
   Val(BS, DI, Er);
   Deci := DI;
end;


Function Hex(BB : Word) : String;
var
   AA, CC : Byte;
   DD : String;
   HexTable : String;
begin
   HexTable := '0123456789ABCDEF';
   DD := '000';
   DD[3] := HexTable[(BB AND $00F) + 1];
   DD[2] := HexTable[((BB AND $0F0) SHR 4) + 1];
   DD[1] := HexTable[((BB AND $F00) SHR 8) + 1];
   Hex := DD;
end;


function AskForBaseAddress(OldOne : String) : Word;
const
   Msg : string[4] = '0';
var
   NewOne, Success, Dummy, Error : Word;
   AddrInputPosX, AddrInputPosY : Word;
begin
   if (OldOne = 'OLD') then OldOne := Msg;
   WriteLn('Please enter the Base Address (0000-FFFF) for your card (in hex)');
   WriteLn('or press ENTER for ', OldOne, '.  ');
   Write('>');
   AddrInputPosX := WhereX; AddrInputPosY := WhereY;
   repeat
      GotoXY(AddrInputPosX, AddrInputPosY);
      ClrEol;
      Readln(Msg);
      Val('$' + Msg, NewOne, Error);
      if (error=0) then begin
         Success := 1;
         Dummy := NewOne;
      end else if (Msg = '') then begin
         GotoXY(AddrInputPosX, AddrInputPosY);
         WriteLn(OldOne);
         Msg := OldOne;
         Success := 1;
         Val('$' + Msg, Dummy, Error);
      end;
   until (Success = 1);
   AskForBaseAddress := Dummy;
end;  { end of AskForBaseAddress }


Procedure Intro;

begin
   ClrScr;
   Writeln('                SAMPLE 1.PAS  :  IDI-48');
   Writeln;
   Writeln('Demonstration program  for accessing IDI-48 input data.');
   Writeln('Program reads each of the IDI-48''s input ports'' 16 input');
   Writeln('channels and displays on/off status of those channels.');
   WriteLn;
   WriteLn;
   WriteLn;
   Address:=AskForBaseAddress('350');
   ClrScr;
   WriteLn;
   WriteLn;
   WriteLn;
   WriteLn('Board Configuration:');
   WriteLn;
   WriteLn(' -- If you are using the IDI-48 option C card, all mode switches');
   WriteLn('    should show OFF.');
   WriteLn(' -- All remaining jumper settings are irrelevant.');
   WriteLn;
   WriteLn;
   WriteLn;
   WriteLn;
   WriteLn('Press ENTER to continue.');
   ReadLn;
   ClrScr;
end; { of Intro }


{*--------------------------------------------------------------------
 *                           Main Program
 *-------------------------------------------------------------------}

Begin

    Intro;
    Done := False;

    Valid := False;
    While Not Valid do
        begin
        ClrScr;
        WriteLn;
        WriteLn;
        WriteLn;
        Write('Enter the input port to read (0,1,2): ');
        Prt := Ord(ReadKey) - Ord('0');
        if (Prt >= 0) And (Prt <= 2) then
           Valid := True;
        end;



	While (Not Done) do
        begin
        ClrScr;
        GotoXY(32,2);
        Writeln(' Reading Port ', Prt);
        GotoXY(32,3);
	   Writeln('Input     Status');
        GotoXY(32,4);
	   Writeln('----------------');


	   { Read the first 8 input channels of current port }
	   Data := Port[Address + ofs[2*Prt]];
	   Mask := 1;
	   for Input := 0 to 7 do
            begin
            GotoXY(32,5+Input);
		  if ((Mask And Data) > 0) then
			Writeln(input:3,'          ON ')
		  else
			Writeln(input:3,'          OFF');
		  Mask := Mask Shl 1;
		  end; { of for input }

	   { Read second 8 input channels for current port }
	   Data := Port[Address + ofs[(2*Prt)+1]];
	   Mask := 1;
	   for Input := 0 to 7 do
            begin
            GotoXY(32,13+Input);
		  if ((Mask And Data) > 0) then
			Writeln(input+8:3,'          ON ')
		  else
			Writeln(input+8:3,'          OFF');
		  Mask := Mask Shl 1;
		  end; { of for input }


	   Writeln;
        Writeln;
        GotoXY(15,24);
	   Writeln('Press "Q" to quit; press any other key to re-read the port');
        c := UpCase(ReadKey);
        if c = 'Q' then
            Done := True;
		end { of while not done }

End. { of main program }