Skip to content

Bitwise Operators

ZX Basic allows Bit Manipulation (bitwise), on every integer type (from 8 to 32 bits).

BITWISE OPERATORS
bAND
bOR
bNOT
bXOR

Except bNOT, all the others require two integral (Byte, Ubyte, Integer, UInteger, Long, ULong) operands. The operation will be applied bit by bit.

bAND

Performs the Bitwise Conjunction and returns 1 for every bit if and only if both bits are 1.

a b result
0 0 0
0 1 0
1 0 0
1 1 1

Example

Binary "mask" that will get only the 4 rightmost bits 0 1 2 3 of a number:

1
PRINT BIN 01110111 bAND BIN 00001111` will print 7, which is 0111

bOR

Performs the Bitwise Disjunction and returns 1 if any of the arguments is 1.

a b result
0 0 0
0 1 1
1 0 1
1 1 1

Example

Ensure an ASCII letter is always in lowercase:

1
PRINT CHR$(CODE "A" OR BIN 10000)
will print a because lowercase letters have bit 5 set.

bNOT

Performs the Bitwise Negation and returns 1 if the arguments is 0 and vice versa. Basically it flips all the bits in an integer number.

a result
0 1
1 0

Example

Invert the first cell (upper-leftmost) in the screen:

1
2
3
4
PRINT AT 0, 0; "A";
FOR i = 0 TO 3
    POKE 16384 + 256 * i, bNOT PEEK(16384 + 256 * i)
NEXT

bXOR

Performs a logical XOR and returns 1 if one and only one of the arguments is 1, 0 if both bits are the same. In essence, returns 1 ONLY if one of the arguments is 1.

a b result
0 0 0
0 1 1
1 0 1
1 1 0
---

Example

Flips an ASCII letter from lower to uppercase and vice versa

1
PRINT CHR$(CODE "A" bXOR BIN 10000)