QBasic binary to decimal

DIM BITS AS INTEGER ' Define total amount of bits in the byte

BITS = 16 ' Define amount of bits to allocate to binary

DIM BYTE1(BITS) AS INTEGER ' BITS-allocated byte
DIM DECIM AS LONG ' Standard output byte as decimal (after translation)


RETRY: ' Retry in case user inputs incorrect number
PRINT "Please enter a valid number between 0 and" + STR$((2 ^ BITS) - 1); ' First prompt w/ evaluation of highest possible input number
INPUT "> ", DECIM ' Ask for user input with second prompt and pass data into DECIM LONG (dimmed previously)
IF DECIM > (2 ^ BITS) - 1 THEN ' Incase user inputs number higher than highest possible input number
    COLOR 12 ' Display message in red for error
    PRINT "Number cannot be over" + STR$((2 ^ BITS) - 1) + "!" ' Display number overflow error
    COLOR 7 ' Return to standard color
    GOTO RETRY ' Go back to retry prompting
ELSEIF DECIM < 0 THEN 'Incase user inputs a negative number
    COLOR 12 ' Display message in red for error
    PRINT "Number cannot be under 0!" ' Display number underflow error
    COLOR 7 ' Return to standard color
    GOTO RETRY ' Go back to retry prompting
END IF ' End input check if statement

FOR X = 1 TO BITS ' Declare all bits in byte as empty
    BYTE1(X) = 0 ' Empty bit
NEXT X ' End for loop

' --- MAIN ALGORITHM CODE EXECUTION HERE ---
' Since binary is calculated from
' the highest value to the lowest
' we need to create a for loop that
' counts from the highest bit to the lowest
' This allows the program to loop until all
' bits have been processed and to make sure that
' the toggled bits are positioned correctly

X = BITS ' Set X to BITS to start loop at TOP
FOR Y = 1 TO BITS ' Begin for loop to declare all bits in byte
    X = X - 1 ' Decrease X by one to down the binary chain
    MODULO = 2 ^ (X) ' Convert bit position into a base-10 decimal number
    IF MODULO <= DECIM THEN ' Is the current decimal number able to be subtracted by the converted bit position?
        BYTE1(X) = 1 ' If so, set that bit position to 1
        DECIM = DECIM - MODULO ' Take away converted bit position from the decimal number
    ELSE ' If not
        BYTE1(X) = 0 ' Set that bit position to 0
    END IF ' End if statement so as to continue the loop
    PRINT ((BYTE1(X))); ' Print that result on screen
NEXT Y ' End bit declaration for loop
PRINT ' Create blankline