@LuzrBum It's a bit complicated. For the 286, Intel abandoned the complicated request/grant scheme but kept HOLD/HLDA. More complex bus arbitration was moved to the 82289 bus controller chip.

The 486 is more than just a 386 and a 387 packaged together. As far as bus arbitration, the 486 has the HOLD/HLDA pins to control the bus, but added BREQ (bus request) and BOFF (backoff).