Although QB64 has _BYTE and _BIT variable types, there may be times that you just want to know which bits are on of off in the byte value or convert the value to a Binary number.
Bits are numbered from 0 to 7 and normally are read from the most significant bit(MSB = 7) to the least significant bit(LSB = 0).
The following example shows how to convert an _UNSIGNED _BYTE or INTEGER value(0 to 255) to a Binary STRING number in QBasic.
DIM byte as _UNSIGNED _BYTE
byte = 222
FOR bit = 7 to 0 STEP -1
IF byte AND 2 ^ bit THEN PRINT "1"; ELSE PRINT "0";
NEXT
Notes: The above code can be adapted to place a value into a bit Arrays for up to 8 flag values in a single Byte.
How upper and lower _BYTE bits are read from an INTEGER value using whole decimal or HEX$ values.
SCREEN 12
COLOR 11: LOCATE 10, 2: PRINT " AH (High Register Byte Bits) AL (Low Register Byte Bits)"
COLOR 14: LOCATE 11, 2: PRINT " 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0"
COLOR 13: LOCATE 14, 2: PRINT " &H8000 4000 2000 1000 800 400 200 100 80 40 20 10 8 4 2 &H1"
COLOR 11: LOCATE 15, 2: PRINT "-32768 16384 8192 4096 2048 1024 512 256 128 64 32 16 8 4 2 1"
FOR i = 1 TO 16
CIRCLE (640 - (37 * i), 189), 8, 9 'place bit circles
NEXT
LINE (324, 160)-(326, 207), 11, BF 'line splits bytes
DO
IF Num THEN
FOR i = 15 TO 0 STEP -1
IF (Num AND 2 ^ i) THEN
PAINT (640 - (37 * (i + 1)), 189), 12, 9
Bin$ = Bin$ + "1"
ELSE: PAINT (640 - (37 * (i + 1)), 189), 0, 9
Bin$ = Bin$ + "0"
END IF
NEXT
COLOR 10: LOCATE 16, 50: PRINT "Binary ="; VAL(Bin$)
COLOR 9: LOCATE 16, 10: PRINT "Decimal ="; Num;: COLOR 13: PRINT " Hex = "; Hexa$
Hexa$ = "": Bin$ = ""
END IF
COLOR 14: LOCATE 17, 15: INPUT "Enter a decimal or HEX(&H) value (0 Quits): ", frst$
first = VAL(frst$)
LOCATE 17, 15: PRINT SPACE$(55)
IF first THEN
COLOR 13: LOCATE 17, 15: INPUT "Enter a second value: ", secnd$
second = VAL(secnd$)
LOCATE 16, 10: PRINT SPACE$(69)
END IF
Num = first + second
Hexa$ = "&H" + HEX$(Num)
LOOP UNTIL first = 0 OR Num > 32767 OR Num < -32768 OR (Num < -1 AND Num > -32768
END
Code by Ted Weissgerber