Even when an A4000 is configured without one, the system will still look for an IDE hard drive on power-up or reset. To allow IDE drives time to spin up, there is a long search built into the 3.0 ROMs, and an even longer one in the 3.1 ROMs (about 30 seconds). A BattMem bit to disable the extra delay with 3.1 ROMs has been reported and finally confirmed, but it enables or disables an additional eight seconds of the wait, and defaults to off. With software, it is possible to remove the delay between resets, but not on power-up (Matthew Frost's "NoIDE" program is available from the disk/misc directory of Aminet).
The only currently-known way to completely disable this delay is by obtaining a small piece of hardware (the circuit is courtesy of Sean Riddle; the instructions are mine, so errors are entirely my fault). With this "IDE ignorer," the search for IDE drives is skipped altogether. You can follow the instructions here to build one, or buy a prebuilt version from Redmond Cable (part number is "40socket-term").
two 4.7K resistors
40-pin crimp-on IDC connector
male-to-male 40-pin header (see below)
Procedure: The two resistors are connected between pin 39 and pin 3, and pin 39 and pin 5 (the effect is to tie IDE data bits 7 and 6 high). Rather than using a piece of whole 40-conductor ribbon cable, I stripped short pieces of individual conductors from one and used fine needle-nose pliers to press these wires into the contacts for pins 3, 5, and 39. Then the crimp-on cover was clipped on top of these.
Since the relevant pins are at either end of the connector, I ran the resistors flat along the side of the connector, using heat-shrink tubing and tape to insulate the leads. The only 40-pin male-to-male header I had didn't have pins long enough to make contact with both connectors, so I just cut three pins off a wire-wrap socket and stuck them in the connectors at pin locations 3, 5, and 39. Physically, this seems to be strong enough to hold the two connectors together.
|-----------####----------------| <--two 4.7K resistors on side
|---------------####------------| of 40-pin IDC connector
=============================== <--40-pin male-to-male header
| | <--A4000 IDE cable connector