or

The Language Reference - Instructions - or

The code a: or src performs a bitwise OR of the accumulator with contents of source argument src. The zero and negative p-flags are modified accordingly.

Usage	Opcode, 6502 mnemonic
a: or #immediate	0x09, ora
a: or @direct	0x0D, ora
a: or @direct[x]	0x1D, ora
a: or @direct[y]	0x19, ora
a: or @zp	0x05, ora
a: or @zp[x]	0x15, ora
a: or @[zp[x]]	0x01, ora
a: or @[zp][y]	0x11, ora

See also: and, xor, not