Here is the correct order of devices the Macintosh checks during the
startup sequence:
1) Floppy drive 0
- On a Macintosh II, IIx, & IIfx this is the right-side internal drive.
- On a Macintosh SE with two floppy drives, this is the lower drive.
- On other systems, this is the internal drive.
2) Floppy drive 1
- On a Macintosh II, IIx, & IIfx this is the left-side internal drive.
- On a Macintosh SE with two floppy drives, this is the upper drive.
- On other systems, this is the external drive.
3) Floppy drive 2
- This applies only to a Macintosh SE with a third floppy drive.
4) Startup device selected via the Startup Disk CDEV
- This may include SCSI or NuBus startup devices.
5) SCSI devices, beginning with ID 6 and ending with ID 0.
6) NuBus startup devices.
- This applies only to a Macintosh II.
Both the "Inside Macintosh V" and the "Macintosh Family Hardware
Reference" manuals state that the internal SCSI device is checked before
any other SCSI device, regardless of SCSI ID. This is NOT True. Unless
the internal SCSI device is selected as the startup device via the Startup
Device CDEV, it has no special priority during the startup process.