DSP2022-S SCSI Disk Drive Installation Guide
3
Note Pin Status of the Vendor-Specific Field
The vendor-specific pin field consists of pins A1–A8. These
pins are used for testing at the factory, setting the SCSI ID
address remotely, and supply power to an external drive
activity light emitting diode (LED). The recommended pin
status is given in Table 1.
Table 1
Vendor-Specific Pin Options
Pin
Function
Status
A1
Reserved for
manufacturing
Leave open
A2
Test UART transmit data
Leave open
A3
+12 V for controller ROM
Leave open
A4
Test UART receive data
Leave open
A5
SCSI ID bit 0
See Table 5
A6
SCSI ID bit 1
See Table 5
A7
SCSI ID bit 2
See Table 5
A8
Drives external activity
LED. LED on indicates
the drive is processing
commands from the
host.
Active low, 24 mA
Note the Use of the SCSI Pin Functions
The 40 SCSI pins carry the SCSI signals, power, and
ground paths for the drive circuitry. Table 2 provides a list
of the pin functions. For a full explanation of the SCSI pin
functions, refer to the ANSI SCSI-2 Specification.
