IBM 2142, 2140 manual Hard, Disk Cable

Hard	Disk Cable			Connectors
Pin		Signal	Name			I/O
1		Host		Reset		O
2		Ground
3		Host		Data	7	I/O
4		Host		Data	8	I/O
5		Host		Data	6	I/O
6		Host		Data	9	I/O
7		Host		Data	5	I/O
8		Host		Data	10	I/O
9		Host		Data	4	I/O
10		Host		Data	11	I/O
11		Host		Data	3	I/O
12		Host		Data	12	I/O
13		Host		Data	2	I/O
14		Host		Data	13	I/O
15		Host		Data	1	I/O
16		Host		Data	14	I/O
17		Host		Data	0	I/O
18		Host		Data	15	I/O
19		Ground				Power
20		No	Connection

Pin	Signal		Name	I/O
21	No	Connection
22	Ground
23	Host		IOW	O
24	Ground			Power
25	Host		IOR	O
26	Ground			Power
27	I/O		Channel Ready	I
28	No	Connection
29	No	Connection
30	Ground			Power
31	Host		IRQ	I
32	No	Connection
33	Host		A1	O
34	No	Connection
35	Host		A0	O
36	Host		A2	O
37	Host		CS0	O
38	Host		CS1	O
39	ACTIVE			I
40	Ground			Power

5-20