AT&T Map/40, Manual

Page: 53 / 60

Performing the Upgrade
4-7
6. Remove the terminating resistors, RN1 and RN2, using needle nose pliers.
Discard the resistors. See Figure 4-3.
Figure 4-3. SCSI Hard Disk Drive
NOTE
:
SCSI ID 0 is the first drive. SCSI ID 1 is the second drive.
Terminating resistors, RN1 and RN2, should be installed if the SCSI
disk drive is the last component on the TDM bus cable. If it is not the
last component, then the resistors should be removed.
1 2
JP2
JP8
PIN 50
PIN 2
RN2
RN1
J6
J3
J1
J7
J5
J2
J4
1 2
JP4
1 2
JP5
Terminating
Resistors
9 7 5 3 1
10 8 6 4 2
MOTOR START
WITH POWER PARITY SCSI ID 0
{
9 7 5 3 1
10 8 6 4 2
{
DIFFERENTIAL
SINGLE ENDED
DIFFERENTIAL
SCSI cable
receptacle
9 7 5 3 1
10 8 6 4 2
SCSI ID 1
{
11
12
Power cable
receptacle
Faceplate
OR