IBM 770 User Manual

   

 

The hard disk drive connected to the system board is removable.
Figure 2-6 shows the pin assignments for the connector on the
system board.

Figure

2-6. Hard Disk Drive Connector Pin Assignments

1

DetectIn

O

31

GND

Ground

2

Jumper A

NC

32

NC

NC

3

Jumper B

O

33

-PDREQ

I

4

Jumper  C

O

34

GND

Ground

5

Jumper  D

O

35

-PDIOW

O

6

RSTDRV

O

36

GND

Ground

7

GND

Ground

37

-PDIOR

O

8

PDD7

I/O

38

GND

Ground

9

PDD8

I/O

39

PIORDY

I

10

GND

Ground

40

CSEL

O

11

PDD6

I/O

41

-PDACK

O

12

PDD9

I/O

42

GND

Ground

13

GND

Ground

43

IRQ14HDD

I

14

PDD5

I/O

44

-IOCS16

I

15

PDD10

I/O

45

PDA1

O

16

GND

Ground

46

-PDIAGHDD O

17

PDD4

I/O

47

GND

Ground

18

PDD11

I/O

48

PDA0

O

19

GND

Ground

49

PDA2

O

20

PDD3

I/O

50

-CS1P

O

21

PDD12

I/O

51

-CS3P

O

22

GND

Ground

52

-DASPHDD

I

23

PDD2

I/O

53

GND

Ground

24

PDD13

I/O

54

VCC5B

Vcc

25

GND

Ground

55

VCC5B

Vcc

26

PDD1

I/O

56

VCC5B

Vcc

27

PDD14

I/O

57

VCC5B

Vcc

28

GND

Ground

58

Reserved

NC

29

PDD0

I/O

59

-HDDDETECTI

30

PDD15

I/O

60

GND

Ground