A Macintosh 800K External Drive or an Apple 3.5 Drive can be connected to the Macintosh 512K enhanced, Plus, SE, SE/ 30, Classic, Classic II/Performa 200, IIcx, IIci, IIsi, Portable, and IIvi/IIvx/Performa 600.
Ports and Pinouts External Floppy Drive Connector: DB-19 - 23 Connect an Apple SuperDrive to a Macintosh SE (FDHD upgrade), SE/30, Classic, Classic II, IIcx, IIci, IIsi, Portable, and IIvi/IIvx/Performa 600.
Connect a Hand Disk 20 to a Macintosh 512K, 512K enhanced, Plus, and SE.
| Pin | Name | Dir | Description |
|---|---|---|---|
| 1 | CGND |
 |
Chassis ground |
| 2 | CGND |
|
Chassis ground |
| 3 | CGND |
|
Chassis ground |
| 4 | CGND |
|
Chassis ground |
| 5 | -12V |
 |
-12 VDC |
| 6 | +5V |
|
+5 VDC |
| 7 | +12V |
|
+12 VDC |
| 8 | +12V |
|
+12 VDC |
| 9 | n/c | - | Not connected |
| 10 | PWM | ? | Regulates speed of the drive |
| 11 | CA0 | ? | Control line to send commands to the drive |
| 12 | CA1 | ? | Control line to send commands to the drive |
| 13 | CA2 | ? | Control line to send commands to the drive |
| 14 | LSTRB | ? | Control line to send commands to the drive |
| 15 | WrReq- | ? | Turns on the ability to write data to the drive |
| 16 | HdSel | ? | Control line to send commands to the drive |
| 17 | Enbl2- | ? | Enables the Rd line (else Rd is tristated) |
| 18 | Rd |
 |
Data actually read from the drive |
| 19 | Wr |
|
Data actually written to the drive |
correct
incorrect