Ampro Corporation LITTLE BOARD P5X - Manual (Page 55)

Little Board/P5x Technical Manual
2–37
Table 2– 31. SCSI Interface Connector (J9)
Pin Signal Function Pin Signal Function
2 DB0* Data Bit 0 (LSB) 4 DB1* Data Bit 1
6 DB2* Data Bit 2 8 DB3* Data Bit 3
10 DB4* Data Bit 4 12 DB5* Data Bit 5
14 DB6* Data Bit 6 16 DB7* Data Bit 7
18 DBP* Data Bit Parity 26 TERM
PWR
Termination +5V DC
32 ATN* Attention 34 GROUND Signal Ground
36 BSY* Busy 38 ACK* Transfer
Acknowledge
40 RST* Reset 42 MSG* Message
44 SEL* Select 46 C/D* Control/Data
48 REQ* Transfer Request 50 I/O* Data Direction
25 N/A Key Pin
1-49(odd), 20,22,24,28,30 Ground
Table 2– 328. J9 Mating Connectors
Connector Type Mating Connector
RIBBON 3M 3425-7600
Latching Clip 3505-8050
DISCRETE WIRE MOLEX HOUSING 22-55-
2502
PIN 16-02-0103
SCSI Interface Configuration
Enable or disable the SCSI interface using Setup. Refer to the Setup description beginning on page
2–62.
Interrupt Request Assignment
The SCSI interface is a PCI peripheral and is assigned to a PCI interrupt using the plug-and-play
logic in the BIOS. No user setup is required
Active Terminators
The SCSI interface uses “active terminators” for the SCSI bus. Active terminators draw less current
than 330/220 ohm terminators (standard for non-UltraSCSI interfaces), are less susceptible to
noise, and are required for the high data transfer rates of UltraSCSI. Termination is controlled by
the SCSI BIOS. There is no user setting.
Only the SCSI devices on each end of the SCSI bus should be terminated.