PC Assembly Practice: Ribbon Cable Orientation for IDC Connectors When connecting a flat ribbon cable to a board or drive IDC connector, which edge of the cable should align with the connector's pin numbering so that the plug is oriented correctly?

Introduction / Context:
Ribbon cables are widely used for internal PC connections (IDE, floppy, front-panel headers, legacy I/O). Correct orientation prevents reversed polarity, which can lead to boot failures or device damage. This question tests practical hardware assembly knowledge: how to identify pin 1 on a ribbon cable and connector.

Given Data / Assumptions:

• A standard flat ribbon cable with a colored edge marker (often red).
• An IDC (insulation-displacement) keyed connector on a PCB or device header.
• Conventional pin numbering where pin #1 is indicated on the board or connector body.

Concept / Approach:

By convention, the colored stripe on a ribbon cable marks the conductor for pin #1. Connectors and PCBs usually have a triangle silkscreen, notch, beveled corner, or “1” printed near pin #1. Lining up the stripe with the pin #1 indicator ensures correct signal-to-pin mapping across the cable conductors.

Step-by-Step Solution:

Verification / Alternative check:

Check the device manual’s connector diagram. Many drives also print “PIN 1” or place pin #1 closest to the power connector, but the authoritative indicator is the printed or molded marking on the header itself.

Why Other Options Are Wrong:

Highest pin number alignment is arbitrary and may be opposite of pin #1. Saying it “does not matter” can short or misroute signals. “Away from the power connector” is not a universal rule. “None of the above” is incorrect because the colored line is the accepted standard for pin #1.

Common Pitfalls:

Assuming power-connector proximity always points to pin #1, ignoring the keyed shroud, or trusting cable twist orientation instead of markings. Always confirm pin #1 marking on the board.

Final Answer:

The colored line in the cable goes to pin #1