If I recall correctly the opcode for the jump absolute was C3, and the conditional versions we C2, CA, etc. The destination was two bytes, 16 bits, little endian.

The JR - jump relative unconditional - was hex 18 followed by the number of bytes to jump, calculated from the byte after the JR instruction to account for the pipelining.

From memory - I could be wrong, but it's close enough.