Specifications

CHAPTER 1

Overview of LaserWriter Pro Hardware

Communication

Note

SCSI ID #6 cannot be used for any of these SCSI devices, since it is

reserved for the LaserWriter Pro printer.

◆

Figure 1-6

30-pin SCSI connector pin designations

Table 1-6

Signal descriptions for 30-pin SCSI connector

Pin number Signal name Description

1 Open Open line

2 /DB0 Bit 0 of SCSI data bus

3, 8, 10, 12, 13,

15, 17, 20, 22, 24

GND Ground

4 /DB1 Bit 1 of SCSI data bus

5 Open Open line

6 /DB2 Bit 2 of SCSI data bus

7 /DB3 Bit 3 of SCSI data bus

9 /ACK Handshake signal; acknowledges a request for data transfer

11 /DB4 Bit 4 of SCSI data bus

14 /DB5 Bit 5 of SCSI data bus

16 /DB6 Bit 6 of SCSI data bus

18 /DB7 Bit 7 of SCSI data bus

19 /DBP Parity bit of SCSI data bus

21 /REQ Request for a data transfer

23 /BSY When active (low) indicates that the SCSI bus is busy

25 /ATN When active (low) indicates an attention condition

continued

123456

789101112

13 14 15 16 17 18

19 20 21 22 23 24

25 26 27 28 29 30