' **********************************************************************
' ** Program name: S1DEB1.BAS -  Version : 1.1   -   01  June  1999   **
' ** Compiler : BASCOM LT, (IDE V.1.20, LIB V.1.27)                   **
' ** Board : GPC(r) 553                                               **
' ** Firm:   grifo(r) ITALIAN TECHNOLOGY                              **
' ** Via Dell' Artigiano 8/6          40016 San Giorgio di Piano (BO) **
' ** Tel.+39 051 892 052     Fax +39 051 893 661                      **
' ** http://www.grifo.com    http://www.grifo.it                      **
' ** sales@grifo.it          tech@grifo.it          grifo@grifo.it    **
' **                                                                  **
' ** Written by:  Graziano Gaiba                                      **
' **********************************************************************
'
' This program shows the hexadecimal code of a key pressed on the PC's
' keyboard on the (red) LEDs of port 4.
' To achieve the visualization of the lines, you should connect the CN5
' connector of GPC(r) 553 board to the CN15 connector of DEB(r) 01 board by
' a 20-pin flat cable.
' ATTENTION! To address correctly the 80552 I/O lines you shuold select the
' 80552 register file. To do this, select tab Misc from the Options/Compiler 
' menu, click in the Register file text box then select the file 80552.DAT.
'
'************************ Compiler Directives  *******************************
'
$romstart = &H8050                 ' start address of machine code
$ramstart = &HD000                 ' start address of data area
$ramsize = &H2800                  ' 10k of data area
$crystal = 22118400                ' clock of microcontroller
$baud = 19200                      ' RS-232 baud rate
$large                             ' 16 bit addressing mode
'
'
'************************** Variable declarations ****************************
'
Dim Char As Byte                   ' Stores key code
Dim T As Byte                      ' General purpose variable
Dim Vbyte As Byte                  ' Value returned by the procedure
                                   ' If 16 then the key is not an hex digit
                                   ' Else the value is the value of 
                                   ' the digit itself
'
'************************** Procedure declarations ****************************
'
Declare Sub Chartest(t As Byte)    ' Decides whether then input parameter is
                                   ' an hex digit or not
'
'***************************** Main Program **********************************
'
Waitms 1                           ' Delay for signals settling
Poke &H20 , 0

P4 = &HFF                          ' Red LEDs OFF
Print "    Demonstration program 1 for section 1 of DEB(r) 01 board"
Print : Print "    Shows on port 4 the value of the hex digit typed on PC."
Print : Print "    Running..."
Print
Do

   Print "Please type the hex digit: " ;' Asks the digit
   Char = 0
   While Char = 0
     Char = Inkey                  ' Reads the serial line
   Wend                            ' until a key is typed
   Print Chr(char)
   Call Chartest (char )
   If Vbyte = 16 Then
      Print "Only chars from 0 to 9, from A to F and from a to f allowed."
   Else
     Vbyte = Not Vbyte             ' Negates the key to pilot the LEDs in
                                   ' negative logic
     P4 = Vbyte                    ' Outputs the negated key
   End If

Loop

End
'
'*************************** End of Main program *****************************
'
'
'******************************* Procedures **********************************
'
' This procedure detects whether its input parameter is an hex digit or not,
' that is whether it is a character between 0 and 9, a and f, A and F or not.
' Sets Vbyte to 16 if it is not.
' Input parameters:
' T	      Byte        Contains the key to be examined
' Output parameters:
' Vbyte 		Byte			Whether the key is an hex digiti it contains its value,
'								else it contains 16
Sub Chartest(t As Byte)
   Vbyte = 16
   If T < 48 Then                  ' It is below "0", then it surely is not
      Exit Sub                     ' an hex digit
   End If
   If T > 57 Then                  ' It is greater than "9", checks if it is letter
      If T < 65 Then               ' It is below "A"
         Exit Sub                  ' Not an hex digit
      End If
      If T > 70 Then               ' It is above "F", could be lowercase
        If T < 97 Then             ' It is below "a"
          Exit Sub                 ' Not an hex digit
        End If
        If T > 102 Then            ' It is above "f"
            Exit Sub               ' Not an hex digit
        Else                       ' Key from "a" to "f",value from 97 to 102
            Vbyte = T - 87         ' Reduced to a field from 10 to 15
        End If
      Else                         ' Key from "A" to "F",value from 65 to 70
         Vbyte = T - 55            ' Reduced to a field from 10 to 15
      End If
   Else                            ' Numeric key
      Vbyte = T - 48               ' Reduced to a field from 0 to 9
   End If
End Sub