Pinouts for connecting an internal SCSI-2 connector (50 pin header) to an external DB25 connector. Function DB25 SCSI DB0 8 2 DB1 21 4 DB2 22 6 DB3 10 8 DB4 23 10 DB5 11 12 DB6 12 14 DB7 13 16 DB Parity 20 18 Gnd 7 20 Gnd 9 22 Gnd 14 24 Termpwr 25 26 Gnd 16 28 Gnd 18 30 ATN 17 32 Gnd 24 34 BSY 6 36 ACK 5 38 RST 4 40 MSG 2 42 SEL 19 44 CO 15 46 REQ 1 48 IO 3 50