ESDI

A hard drive interface that has seen better times. Another replacement for SCSI that eventually became IDE. ESDI and IDE suck. If not for them, SCSI would be a lot cheaper. Instead, we're stuck with an inferior interface that only supports&two drives and can't even drive both of them at the same time.

Enhanced Small Device Interface. Disk drive interface introduced in the late 1980s that never really caught on. Had separate Cables for control and data, unlike SCSI and IDE, which use one cable for both. It came after IDE, and is not related to it.

Control cable pinout:

1

GND

Ground

2

SH3

Select Head 3

3

GND

Ground

4

SH2

Select Head 2

5

GND

Ground

6

W

Write Gate

7

GND

Ground

8

CON

Configuration Data

9

GND

Ground

10

TACK

Transfer Acknowledge

11

GND

Ground

12

AT

Attention

13

GND

Ground

14

SH0

Select Head 0

15

GND

Ground

16

FOUND

Sector Found

17

GND

Ground

18

SH1

Select Head 1

19

GND

Ground

20

INDEX

Index

21

GND

Ground

22

READY

Ready

23

GND

Ground

24

TRQ

Transfer Request

25

GND

Ground

26

SD1

Select Drive 1

27

GND

Ground

28

SD2

Select Drive 2

29

GND

Ground

30

SD3

Select Drive 3

31

GND

Ground

32

R

Read gate

33

GND

Ground

34

CD

Command Data

Data Connector:

1

DS

Drive Selected

2

FOUND

Sector Found

3

DONE

Seek Complete

4

AME

Address Mark Enable

5

N/A

Reserved

6

GND

Ground

7

WC+

Write Clock +

8

WC-

Write Clock -

9

CC

Cartridge Changed

10

RRC+

Read Ref Clock +

11

RRC-

Read Ref Clock -

12

GND

Ground

13

NW+

NRZ Write data +

14

NW-

NRZ Write Data -

15

GND

Ground

16

GND

Ground

17

NR+

NRZ Read data +

18

NR-

NRZ Read data -

19

GND

Ground

20

GND

Ground