Seagate ST32430N - Hawk 2.1 GB Hard Drive Product Manual page 55

Product Manual - Hawk 2LP Family SCSI-2 (Volume 1), Rev. A
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Total interface cable length must not exceed that specified in paragraph
11.6.2.2. (including host adapter/initiator).
* Closed end type connector used.
** Open end type (in-line application) connector used.
*** Host need not be on the end of the daisy-chain. Another device can be
on the end with the terminator, the host having no terminator.
Figure 11.6.3-2. Interface cabling
Table 11.6.3-1a. Single ended, 50 pin cable pin assignments (Nonshielded connector) (N models)
Signal
-DB (0)
-DB (1)
-DB (2)
-DB (3)
-DB (4)
-DB (5)
-DB (6)
-DB (7)
-DB (P)
GROUND
GROUND
GROUND
TERMPWR
GROUND
Notes.
1. All odd pins except pin 25 are connected to ground. Pin 25 is left open.
Pin 25 must not be connected to ground at the HOST end or the drive end of the cable. If the I/O
connector should accidentally be plugged upside down, terminator power on pin 26 will be shorted to
ground.
2. The minus sign next to the signals indicates asserted state is the low voltage of the two levels used for logic
signals.
Host Adapter/Initiator
T
*
* *
Disc Drive or
Other SCSI
Device
VIEW B - T indicates termination required
Pin Number
2
4
6
8
10
12
14
16
18
20
22
24
26
28
SCSI Device
* * *
1 thru 8
SCSI Devices
* * *
Disc Drive or Disc Drive or
Other SCSI Other SCSI
Device Device
Signal
GROUND
-ATN
GROUND
-BSY
-ACK
-RST
-MSG
-SEL
-C/D
-REQ
-I/O
Caution
T
Pin Number
30
32
34
36
38
40
42
44
46
48
50
47