That’s probably because both the Z80 and the 8086 are derivatives of the 8080, which also had 0C9H as the opcode for return. Report comment. Reply. Eric says: July 17, 2023 at 5:26 am ...

If Intel only had retroactively updated the 8088/8086 line with the “8086-2” ISA (there are 8086-1 and 8086-2 chips, but they’re not related to the instructions set). The Z80 series had an ...

Initially, the 8086 was intended to be a stopgap product while Intel worked feverishly to finish its real next-generation microprocessor -- the iAPX 432, Intel's first 32-bit microprocessor.