DECLARE FUNCTION AskForBaseAddress! (OldOne AS INTEGER)
CLS
PRINT "****************************************************************************"
PRINT "*                 QuickBASIC SAMPLE #1: QSAMPLE1.BAS                       *"
PRINT "*                                                                          *"
PRINT "*  This sample will prompt the user for a voltage between 0 and 10 volts,  *"
PRINT "*  then calculate the actual voltage based on the resolution of the DAC and*"
PRINT "*  output the voltage to the desired DAC channel.                          *"
PRINT "*                                                                          *"
PRINT "*                                                                          *"
'*  LAST MODIFICATION: February 5, 1996                                           *
'*                                                                                *
PRINT "****************************************************************************"


'****************************************************************************
'*                                                                          *
'*  FUNCTION: main program - global routine                                 *
'*                                                                          *
'*   PURPOSE: Controls overall program execution and determines exit.       *
'*                                                                          *
'*     INPUT: None.                                                         *
'*                                                                          *
'*     CALLS: None.                                                         *
'*                                                                          *
'*    OUTPUT: None.                                                         *
'*                                                                          *
'****************************************************************************



   PRINT "Board Configuration:"
   PRINT
   PRINT "--The Base Address should be set to the address which will be"
   PRINT "  entered during program execution."
   PRINT "--DACs must be placed in the 10V unipolar mode."
   PRINT "--2's complement jumper should be removed."
   PRINT : PRINT : PRINT
   Address% = AskForBaseAddress!(&H340)
   PRINT : PRINT

DO
   CLS
   PRINT : PRINT : PRINT
   GOSUB writeDAC
   PRINT : PRINT : PRINT : PRINT
   PRINT "Would you like to output another value (Y or N)? "
   key$ = INPUT$(1)
LOOP UNTIL key$ = "N" OR key$ = "n"
OUT Address% + 8 + (2 * DACnumber), 0
OUT Address% + 8 + (2 * DACnumber + 1), 0
CLS
END      ' PROGRAM

'****************************************************************************
'*                                                                          *
'*  FUNCTION: writeDAC - local routine                                      *
'*                                                                          *
'*   PURPOSE: Prompts the user for DAC number and voltage, then calculates  *
'*            the actual output voltage based on resolution, displays it    *
'*            and writes the value to the DAC.                              *
'*                                                                          *
'*     INPUT: None.                                                         *
'*                                                                          *
'*     CALLS: None.                                                         *
'*                                                                          *
'*    OUTPUT: None.                                                         *
'*                                                                          *
'****************************************************************************
writeDAC:

' prompt for the DAC number and desired voltage.
CLS
PRINT : PRINT : PRINT
PRINT "Enter the DAC number (0 through 1 only): "

DO
   LOCATE 4, 42
   PRINT "     "
   DACnumber$ = INPUT$(1)
   LOCATE 4, 42
   PRINT DACnumber$
   DACnumber = VAL(DACnumber$)
LOOP WHILE DACnumber < 0 OR DACnumber > 1

PRINT : PRINT : PRINT : PRINT : PRINT
INPUT "Enter a voltage between 0.000v to 9.997v: ", voltage#
WHILE voltage# < 0 OR voltage# > 9.997
   LOCATE 10, 43
   PRINT "                    "
   LOCATE 10, 43
   INPUT ; voltage#
WEND
PRINT
PRINT

'  compute the digital output needed for this value and the actual voltage
'  that will be expected, and display the voltage.
counts# = voltage# / .002441
cnts& = counts#
expected# = cnts& * .002441
PRINT : PRINT
PRINT "Due to the 12-bit resolution of the DAC, you should expect "
PRINT USING "to see a voltage of #.### "; expected#

' Prepare and write values to control word
lowbyte% = cnts& MOD 256
hibyte% = INT(cnts& / 256)

OUT Address% + 8 + (2 * DACnumber), lowbyte%
OUT Address% + 8 + (2 * DACnumber + 1), hibyte%

RETURN

FUNCTION AskForBaseAddress (OldOne AS INTEGER)
   Msg$ = ""
   NewOne% = 0: Success = 0: Dummy% = 0
   AddrInputPosX = 0: AddrInputPosY = 0

   PRINT "Please enter the Base Address (0000-FFFF) for your card (in hex)"
   PRINT "or press ENTER for "; HEX$(OldOne%); "."
   PRINT ">";
   AddrInputPosX = POS(0): AddrInputPosY = CSRLIN
   WHILE Success = 0
     LOCATE AddrInputPosY, AddrInputPosX
     PRINT "                                                                               "
     LOCATE AddrInputPosY, AddrInputPosX
     LINE INPUT Msg$
     NewOne% = VAL("&H0" + LEFT$(Msg$, 4))
     Success = 1
     Dummy% = NewOne%
     ELSEIF (Msg$ = "") THEN
        LOCATE AddrInputPosY, AddrInputPosX
        PRINT HEX$(OldOne%)
        Success = 1
        Dummy% = OldOne%
     END IF
  WEND
  AskForBaseAddress = Dummy%
END FUNCTION