PowerBook Models Using SCSI Disk Mode
The SCSI Disk Mode feature exists on all PowerBook models except the PowerBook 140, 145, 145B, 150, and 170. Those PowerBook computers that DO support the feature have it coded into their read-only memory (ROM) on the logic board.
PowerBook Models Using HD Target Mode
When you are using a PowerBook 190 or 5300 series computer, this disk mode function is no longer called SCSI Disk Mode. It is called HD Target Mode because these PowerBook models have an integrated drive electronics (IDE) hard drive, not a SCSI hard drive. Although the terminology is different, the function is the same.
Which SCSI Cable?
You must use the appropriate SCSI cable for SCSI Disk Mode. The part number for the Apple HDI-30 Disk Adapter cable is M2539LL/A.
You can distinguish the Disk Adapter cable from a standard PowerBook SCSI cable by looking at the number of pins in the connector on the end of the cable that plugs into the PowerBook.
* The Apple HDI-30 Disk Adapter (M2539LL/A) cable's connector has 30 pins. It is the thirtieth pin that puts the computer into SCSI Disk or HD Target Mode.
* The Apple HDI-30 SCSI System (M2538LL/A) cable's connector has 29 pins. It is used to connect external SCSI devices, like CD-ROMs and hard drives, to your PowerBook computer.
What About PowerBook Duo Computers?
For the PowerBook 200 and 2300 Series (Duo) computers, you must use the Apple HDI-30 Disk Adapter cable in addition to the Duo MiniDock to enable the Duo to be used in SCSI Disk Mode.
**NOTE** The Duo Dock, Duo Dock II, and Duo Dock Plus do not support SCSI Disk Mode. When a PowerBook Duo computer is docked (except for the MiniDock) its SCSI capabilities are the same as any other desktop Macintosh computer, none of which support any kind of SCSI Disk or Target mode function.
This article was published in the Information Alley on 17 September 1996.