HDI Connector
This page provides the SCSI bus interface as found on an Apple computer [Macintosh] over a 30-pin HDI connector.
A description is provided along with the pinouts. This interface is no longer used on current production models.
Only connector data is shown, no electrical standards or cabling information is provided here;
Refer to the main SCSI Bus page which provides a detailed description of the SCSI bus interface and additional pin out options.
The term SCSI stands for Small Computer Systems Interface; which defines a number of different interface configurations.
The version used here is SCSI I, which used 8-bit single-ended data. SCSI I was released in 1986, & replaced by SCSI II in 1994.
Follow these links to Connector manufacturers, or Cable manufacturers, and a list of Cable Assemblies manufacturers.
However those topics are to general listing of vendors, which produce a number of connector styles.
The Apple Computer HDI-30 SCSI Pin out and Signal names on a HDI (Square) connector.
HDI stands for High Density Interconnect [HDI also comes in additional pin configurations]
The HDI-30 was found on a number of printers, to include:
LaserWriter 12/600, LaserWrite Pro 630, and Apple Macintosh PowerBooks
| Pin # | Pin name | Pin Description |
|---|---|---|
| 1 | Open | Open Line |
| 2 | /DB0 | SCSI Bit 0 |
| 3 | GND | GROUND |
| 4 | /DB1 | SCSI Bit 1 |
| 5 | Open | Open Line |
| 6 | /DB2 | SCSI Bit 2 |
| 7 | /DB3 | SCSI Bit 3 |
| 8 | GND | GROUND |
| 9 | /ACK | Acknowledge |
| 10 | GND | GROUND |
| 11 | /DB4 | SCSI Bit 4 |
| 12 | GND | GROUND |
| 13 | GND | GROUND |
| 14 | /DB5 | SCSI Bit 5 |
| 15 | GND | GROUND |
| 16 | /DB6 | SCSI Bit 6 |
| 17 | GND | GROUND |
| 18 | /DB7 | SCSI Bit 7 |
| 19 | /DBP | Parity Bit |
| 20 | GND | GROUND |
| 21 | /REQ | Request for Data |
| 22 | GND | GROUND |
| 23 | /BSY | Busy when low |
| 24 | GND | GROUND |
| 25 | /ATN | Attention |
| 26 | /C/D | Low, Data on Bus. High, Control on Bus |
| 27 | /RST | SCSI Bus Reset |
| 28 | /MSG | Message phase is active |
| 29 | /SEL | Select |
| 30 | /I/O | Indicates direction of data |
Editor note; The SCSI interface is no longer actively used by any PC manufacturer. Of course there's nothing wrong with the physical connector. |  HDI-30 Connector |
Topic Navigation: Engineering Home > Interface Buses > Personal Computer Buses > Apple Computer Buses > HDI-30 Interface.
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