{****************************************************************************
*                            Digital Input Sample                           *
*  This program constantly talks to the RDI-54 pod, which must be located   *
*  at pod address 00 (non-addressed mode).  This program displays all 54    *
*  digital input bits and all 54 counters.  Gate (hi or lo) is selectable.  *
****************************************************************************}

USES CommDRV, crt;

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 }


Function Hex(BB : Word) : String;
Var
 AA, CC : Byte;
 DD : String;
 HexTable : String;
Begin
 HexTable := '0123456789ABCDEF';
 DD := '00';
 DD[2] := HexTable[(BB AND $0F) + 1];
 DD[1] := HexTable[((BB AND $F0) SHR 4) + 1];
 Hex := DD;
End;


{ MAIN PROGRAM }

var
   Address, error : word;
   index, nybble, counter, color, value, mask : integer;
   charhit, key : char;
   returnStr, msg1, msg2: string;
   dStr : string[2]; messageStr : string[3];

BEGIN

   index := 0; nybble := 0; counter := 0; color := 0; value := 0; mask := 0;
   dStr := '0'; messageStr := '';

   ClrScr;
   WriteLn;
   WriteLn('                  Sample One  :  Digital Input Sample        ');
   WriteLn;
   WriteLn('This program displays all 54 digital input bits and all 54 counters');
   WriteLn('Pod must be set at address 00 (non-addressed mode) and be in 28800');
   WriteLn('communications.  No other settings are required.');
   WriteLn;
   Address := AskForBaseAddress('300');
   ClrScr;

   GotoXY(1,4);
   WriteLn('Board Configuration:');
   GotoXY(1,6);
   WriteLn(' -- Pod must be at address 00, and 28800 baud');
   WriteLn(' -- All remaining jumper settings are irrelevant');
   GotoXY(1,12);
   WriteLn('Press any key to continue, or "E" to exit.');
   key := ReadKey;

   if (UpCase(key) = 'E') then Halt;

   initCommCard(28800, Address);               { Setup the 16450 chip }

   ClrScr;

   GotoXY(1,3);
   WriteLn('    Most significant nybble                       Least significant nybble');
   GotoXY(17,7);
   WriteLn('RDI-54 Sample 1, Digital Inputs and Counters');
   GotoXY(8,8);
   WriteLn('Press SPACE to reset current counter, ENTER to reset all counters.');
   GotoXY(30,9);
   WriteLn('Press ESC to exit.');
   repeat
      writePod(Address,'I');
      readPod(Address,returnStr);

      if (Length(returnStr) = 14) then       { make sure read all characters }
      begin
         GotoXY(6,5);
         for nybble := 1 to 14 do
         begin
            dStr[1] := returnStr[nybble];
            Val('$' + dStr, value, error);
            mask := $08;
            for index := 0 to 3 do
            begin
               textcolor(7);
               if (value AND mask) <> 0 then
                  Write('1')
               else
                  Write('0');
               mask := (mask SHR 1);
            end;   { end for (index) loop }
            Write(' ');
         end;  { end for (nybble) loop }

         textcolor(color);
         msg1 := Hex(counter);
         messageStr := ('c' + msg1 + messageStr);
         writePod(Address, messageStr);
         readPod(Address, returnStr);
         Val('$' + returnStr, value, error);

         GotoXY(5 + ((counter DIV 9) * 12), 12 + (counter MOD 9));

         if (counter = 0) then
         begin
            if (color = 7) then color := 2 else color := 7;
            TextColor(color);
         end;
         msg2 := Hex(value);
         WriteLn(counter:2,' : ',msg2);

         if (keypressed) then charhit := ReadKey;

         case charhit of
            #13 :
            begin
               writePod(Address, 'rall');
               readPod(Address, returnStr);
               counter := -1;
               charhit := #0;
            end;
            #32 :
            begin
               messageStr := ('r' + msg1 + messageStr);
               writePod(Address, messageStr);
               readPod(Address,returnStr);
               counter := (counter - 1);
               charhit := #0;
            end;
         end;
         counter := (counter + 1);
         counter := (counter MOD 54);
      end; { end if }
   until charhit = #27;
   TextColor(7);
   ClrScr;
END.