0x100ziwen

千字文(Qiānzìwén) in machine code

rule

Must contain exactly 256 bytes, each used only once
Must be arranged to 64 lines of 4 bytes (5-byte or larger opcode is forbidden)
Must rhyme (i.e. the last nibble must match) at the end of every other line; that is,

xx xx xx xx    xx xx xx x3
xx xx xx xx    xx xx xx x3