[comp.sys.apple] Apple Tech Notes: //gs Disks

ranger@ecsvax.UUCP (Rick N. Fincher) (12/15/86)

Apple IIGS: Connecting Disk Drives The Apple IIGS is capable of using all
drives available for the Apple IIe, as well as drives built for the Apple
IIGS, including the Disk II, Duodisk, Unidisk, Unidisk 3.5, Profile, Apple 3.5
Drive, Apple 5.25 Drive, and SCSI-20. Some of these drives may be plugged
directly into the SmartPort on the back of the IIGS, while others require
an interface card in one of the expansion I/O slots.   The following drives
may be plugged into the SmartPort's DB-19 connector:   -- one Duodisk   --
two Unidisk 5.25 drives   -- two Unidisk 3.5 drives   -- two Apple 5.25
drives   -- two Apple 3.5 drives   Only under Prodos 16 may a combination
of up to six drives be daisy-chained to the SmartPort. The chain MUST
occur in the order given below and may include up to two (excepting the
DuoDisk) in each of the following three categories:     -- nearest to IIGS
(maximum of two):        1. Apple 3.5 Drives        2. Unidisk 3.5 drives     --
farthest from IIGS (maximum of two):        3. 5.25 disk drives: Disk II's,
Unidisk 5.25 drives, Apple 5.25 drives           or ONE Duodisk drive   Under
Prodos 8 (also known as Prodos 1.2), four drives are accessible through the
SmartPort. These may be a combination of Apple 3.5 drives, Unidisk 3.5
drives, a RAM disk, and a ROM disk, under the same order restrictions as
above.   The SmartPort is mapped to slot 5, so drives connected directly to
the port are accessed as slot 5, drive 1 and slot 5, drive 2. When more than
two drives are used under Prodos 8, or if the RAM disk is active, "phantom
slots" are assigned.   To be used on the Apple IIGS, the Disk II requires a
Disk II Controller Card, just as on the Apple II or Apple IIe. The drive may
be accessed through the slot used for the card, most likely slot 6, in which
case the two possible drives are referred to as slot 6, drive 1 and slot 6,
drive 2.   A SCSI Interface Card is needed to use the Apple Hard Disk 20SC
on the Apple IIGS  A Profile Interface Card must be used with a 5 or 10
Megabyte Profile, accessible by referencing the slot where the interface
card resides or by the ProFile's ProDOS pathname.   The Apple IIGS control
panel allows you to select the slot from which the computer will be
booted, or you may choose to scan slots on bootup to find a device that is ready. Apple Technical Communications