The external floppy disk drive connector is featured on the Macintosh 128K, 512K, 512K enhanced, Plus, SE, SE/30, Classic, Classic II, IIcx, IIci, IIsi, Portable, and Performa 200.
A Macintosh 400K External Drive can be connected to the Macintosh 128K, 512K, 512K enhanced, Plus, SE, and Portable.
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, IIcx, IIci, IIsi, and Performa 200.
An Apple SuperDrive can be connected to the Macintosh SE (with SuperDrive upgrade), SE/30, Classic, Classic II, IIcx, IIci, IIsi, and Performa 200
An Apple Hard Disk 20 can be connected to a Macintosh 512K, 512K enhanced, Plus, and SE.
Connector type: DB-19.
Pin Name Description/Notes
. 1 CGND Chassis ground
. 2 CGND Chassis ground
. 3 CGND Chassis ground
. 4 CGND Chassis ground
. 5 -12V
. 6 +5V
. 7 +12V
. 8 +12V
. 9 N/C Not connected
. 10 PWM Regulates speed of the drive
. 11 PH0 Control line to send commands to drive
. 12 PH1 Control line to send commands to drive
. 13 PH2 Control line to send commands to drive
. 14 PH3 Control line to send commands to 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