Please do. The limit on m68k Mac IDE is 128 gigs due to the fact that the IDE of the time supported 28 bit addressing giving 2^28 (268,435,456) sectors of 512 bytes each for 137,438,953,472 bytes total, or 128 gigabytes, or what some people nowadays call 128 gibibytes.
IDE drives with 48 bit addressing can access 2^57 bytes (2^48 + 9 bits in a sector), or 144,115,188,075,855,872 bytes, or 128 petabytes.
Not sure where the 4 terabyte number comes from, since legacy SCSI is limited to 2 terabytes... But I'd love to learn more, especially if I'm wrong!
IDE drives with 48 bit addressing can access 2^57 bytes (2^48 + 9 bits in a sector), or 144,115,188,075,855,872 bytes, or 128 petabytes.
Not sure where the 4 terabyte number comes from, since legacy SCSI is limited to 2 terabytes... But I'd love to learn more, especially if I'm wrong!