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SCSI Internal (Single-ended)

SCSI=Small Computer System Interface.
Based on an original design by Shugart Associates. SCSI was ratified in 1986.

(At the controller & harddisk)

(At the cable)

50 PIN IDC MALE at the controller & harddisk.
50 PIN IDC FEMALE at the cable.

Pin Name Dir Description

2 DB0 < > Data Bus 0

4 DB1 < > Data Bus 1

6 DB2 < > Data Bus 2

8 DB3 < > Data Bus 3

10 DB4 < > Data Bus 4

12 DB5 < > Data Bus 5

14 DB6 < > Data Bus 6

16 DB7 < > Data Bus 7

18 PARITY < > Data Parity (odd Parity)

20 GND ------ Ground

22 GND ------ Ground

24 GND ------ Ground

26 TMPWR < > Termination Power

28 GND ------ Ground

30 GND ------ Ground

32 /ATN < Attention

34 GND ------ Ground

36 /BSY < > Busy

38 /ACK < Acknowledge

40 /RST < > Reset

42 /MSG > Message

44 /SEL < > Select

46 /C/D > Control/Data

48 /REQ > Request

50 /I/O > Input/Output

SCSI Internal (Differential)

(at the controller & harddisk.) (At the cable)

50 PIN IDC MALE at the controller & harddisk.
50 PIN IDC FEMALE at the cable.

Pin Name Dir Description

01 GND ------ Ground

02 GND ------ Ground

03 +DB0 < > +Data Bus 0

04 -DB0 < > -Data Bus 0

05 +DB1 < > +Data Bus 1

06 -DB1 < > -Data Bus 1

07 +DB2 < > +Data Bus 2

08 -DB2 < > -Data Bus 2

09 +DB3 < > +Data Bus 3

10 -DB3 < > -Data Bus 3

11 +DB4 < > +Data Bus 4

12 -DB4 < > -Data Bus 4

13 +DB5 < > +Data Bus 5

14 -DB5 < > -Data Bus 5

15 +DB6 < > +Data Bus 6

16 -DB6 < > -Data Bus 6

17 +DB7 < > +Data Bus 7

18 -DB7 < > -Data Bus Parity7

19 +DBP < > +Data Bus Parity (odd Parity)

20 -DBP < > -Data Bus Parity (odd Parity)

21 DIFFSENS ? ???

22 GND ------ Ground

23 res - Reserved

24 res - Reserved

25 TERMPWR < > Termination Power

26 TERMPWR < > Termination Power

27 res - Reserved

28 res - Reserved

29 +ATN < +Attention

30 -ATN < -Attention

31 GND ------ Ground

32 GND ------ Ground

33 +BSY < > +Bus is busy

34 -BSY < > -Bus is busy

35 +ACK < +Acknowledge

36 -ACK < -Acknowledge

37 +RST < > +Reset

38 -RST < > -Reset

39 +MSG > +Message

40 -MSG > -Message

41 +SEL < > +Select

42 -SEL < > -Select

43 +C/D > +Control or Data

44 -C/D > -Control or Data

45 +REQ > +Request

46 -REQ > -Request

47 +I/O > +In/Out

48 -I/O > -In/Out

49 GND ------ Ground

50 GND ------ Ground

SCSI-II External Hi D-Sub (Single-ended)

(At the controller & devices).

(To the cable)

50 PIN HI-DENSITY D-SUB FEMALE at the controller & devices.
50 PIN HI-DENSITY D-SUB MALE at the cable.

Pin Name Dir Description

1-25 GND ------ Ground

26 DB0 < > Data Bus 0

27 DB1 < > Data Bus 1

28 DB2 < > Data Bus 2

29 DB3 < > Data Bus 3

30 DB4 < > Data Bus 4

31 DB5 < > Data Bus 5

32 DB6 < > Data Bus 6

33 DB7 < > Data Bus 7

34 PARITY < > Data Parity (odd Parity)

35 GND ------ Ground

36 GND ------ Ground

37 GND ------ Ground

38 TMPWR < > Termination Power

39 GND ------ Ground

40 GND ------ Ground

41 /ATN < Attention

42 n/c - Not connected

43 /BSY < > Busy

44 /ACK < Acknowledge

45 /RST < > Reset

46 /MSG > Message

47 /SEL < > Select

48 /C/D > Control/Data

49 /REQ > Request

50 /I/O > Input/Output

SCSI-II External Hi D-Sub (Differential)

(At the controller & devices)

(To the cable)

50 PIN HI-DENSITY D-SUB FEMALE at the controller & devices.
50 PIN HI-DENSITY D-SUB MALE at the cable.

Pin Name Dir Description

01 GND ----- Ground

02 +DB0 < > +Data Bus 0

03 +DB1 < > +Data Bus 1

04 +DB2 < > +Data Bus 2

05 +DB3 < > +Data Bus 3

06 +DB4 < > +Data Bus 4

07 +DB5 < > +Data Bus 5

08 +DB6 < > +Data Bus 6

09 +DB7 < > +Data Bus 7

10 +DBP < > +Data Bus Parity (odd Parity)

11 DIFFSENS ? ???

12 res - Reserved

13 TERMPWR < > Termination Power

14 res - Reserved

15 +ATN < +Attention

16 GND ----- Ground

17 +BSY < > +Bus is busy

18 +ACK < +Acknowledge

19 +RST < > +Reset

20 +MSG > +Message

21 +SEL < > +Select

22 +C/D > +Control or Data

23 +REQ > +Request

24 +I/O > +In/Out

25 GND ----- Ground

26 GND ----- Ground

27 -DB0 < > -Data Bus 0

28 -DB1 < > -Data Bus 1

29 -DB2 < > -Data Bus 2

30 -DB3 < > -Data Bus 3

31 -DB4 < > -Data Bus 4

32 -DB5 < > -Data Bus 5

33 -DB6 < > -Data Bus 6

34 -DB7 < > -Data Bus Parity7

35 -DBP < > -Data Bus Parity (odd Parity)

36 GND ----- Ground

37 res - Reserved

38 TERMPWR < > Termination Power

39 res - Reserved

40 -ATN < -Attention

41 GND ----- Ground

42 -BSY < > -Bus is busy

43 -ACK < -Acknowledge

44 -RST < > -Reset

45 -MSG > -Message

46 -SEL < > -Select

47 -C/D > -Control or Data

48 -REQ > -Request

49 -I/O > -In/Out

50 GND ----- Ground

SCSI External D-Sub (PC/Amiga/Mac)

(At the controller)

At (the cable) 25 PIN D-SUB FEMALE at the controller.
25 PIN D-SUB MALE at the cable.

Pin	Name	Dir	Description
1	/REQ	>	Request
2	/MSG	>	Message
3	I/O	>	Input/Output
4	/RST	< >	Reset
5	/ACK	<	Acknowledge
6	BSY	< >	Busy
7	GND	-----	Ground
8	DB0	< >	Data Bus 0
9	GND	-----	Ground
10	DB3	< >	Data Bus 3
11	DB5	< >	Data Bus 5
12	DB6	< >	Data Bus 6
13	DB7	< >	Data Bus 7
14	GND	-----	Ground
15	C/D	>	Control/Data
16	GND	-----	Ground
17	/ATN	<	Attention
18	GND	-----	Ground
19	/SEL	< >	Select
20	PARITY	< >	Data Parity
21	DB1	< >	Data Bus 1
22	DB2	< >	Data Bus 2
23	DB4	< >	Data Bus 4
24	GND	-----	Ground
25	TMPWR	< >	Termination Power

SCSI External D-Sub (Future Domain)

Seems to be available on some Future Domain SCSI-controllers only.

(At the controller)

(At the cable)

25 PIN D-SUB FEMALE at the controller.
25 PIN D-SUB MALE at the cable.

Pin Name Dir Description

1 GND ----- Ground

2 DB1 < > Data Bus 1

3 DB3 < > Data Bus 3

4 DB5 < > Data Bus 5

5 DB7 < > Data Bus 7

6 GND ----- Ground

7 /SEL < > Select

8 GND ----- Ground

9 TMPWR < > Termination Power

10 /RST < > Reset

11 C/D > Control/Data

12 I/O > Input/Output

13 GND ----- Ground

14 DB0 < > Data Bus 0

15 DB2 < > Data Bus 2