There do not appear to be ROM switchers for the A4000. The ageing motherboard and CPU card could definitely benefit from not having to endure the physical stresses if a user wants to run DiagROM to test motherboard components.

Is the remaining end-user market too small? The Romulator (SD-card based) design doesn't have an A4000 model. The Kipper2K(?) keyboard reset based one apparently has manufacturing problems which is not resolved so thus no longer sold to A4000 users.

At this point in time, I would be perfectly satisfied with a simple version based on toggle switches for the pair of ROMs. Is this something that end-users could build for themselves with ribbon cable and some chip sockets? Anyone willing to help brainstorm a design? The immediate concern is those with 030EC cards. Due to the inverted component layout on the A3630, the underside physical clearance is extremely limited.