I/O Card, 10 pin DIP, Ribbon Cable Connector, COM1 or COM2

I/O Card, 16 pin DIP, Ribbon Cable Connector, Game/Joystick Port

I/O Card, 20 pin DIP, Ribbon Cable Connector, ST506 or ESDI, Data Connector

I/O Card 34 pin DIP Ribbon Cable Connector Floppy Drive or ST506/ESDI data connector

I/O Card, 40 pin DIP, Ribbon Cable Connector, IDE or EIDE Connector

I/O Card, 50 pin DIP, Ribbon Cable Connector, SCSI bus

Pin 1 of DIP connector is indicated by:

a number 1 on the silkscreen,
a square or oval pad
and/or an angle in the silkscreen outline

Pin 1 on a ribbon cable is indicated by a red line marked on one edge of the ribbon cable.