Instruction manual

Appendix A Genesis MP70 ◆
SCSI Port
Genesis MP uses a SCSI bus for external SCSI devices. The
external SCSI connector is a 25-pin D-type connector. Refer to the
table for the SCSI Connector pin assignments.
The external SCSI port has automatic termination capability. When
no external SCSI device is connected, the automatic termination
capability is active. When one or more external SCSI devices are
connected, the automatic termination is removed. The last SCSI
device on the bus requires termination.
SCSI Connector Pin Assignments
Int. Ext. Signal Signal
Pin Pin Name Description
2 8 /DB0 Bit 0 of SCSI data bus
4 21 /DB1 Bit 1 of SCSI data bus
6 22 /DB2 Bit 2 of SCSI data bus
8 10 /DB3 Bit 3 of SCSI data bus
10 23 /DB4 Bit 4 of SCSI data bus
12 11 /DB5 Bit 5 of SCSI data bus
14 12 /DB6 Bit 6 of SCSI data bus
16 13 /DB7 Bit 7 of SCSI data bus
18 20 /DBP Parity bit of SCSI data bus
25  n.c. Not Connected
26 25 TPWR +5 V terminator power
32 17 /ATN Attention
36 6 /BSY Bus busy
38 5 /ACK Handshake acknowledge
40 4 /RST Bus reset
42 2 /MSG Message phase
43 19 /SEL Select
46 15 /C/D Control or data
48 1 /REQ Handshake request
50 3 /I/O Input or output
20,22,24,28 7,9,14,16, GND Ground
30,34,& all 18and 24
odd pins
except pin 25