PC Card (PCMCIA) form factors: What is true about Type I PC Cards when comparing PCMCIA card types used in laptops?

Introduction / Context:
PCMCIA (PC Card) technology defined three primary card thicknesses for laptop expansion: Type I, Type II, and Type III. Knowing the mechanical differences helps identify what functions each card typically supported and which slots accept them.

Given Data / Assumptions:

• We are comparing PC Card types by physical thickness and typical use.
• Focus is on Type I relative to other types.
• Legacy laptop hardware is implied.

Concept / Approach:

Type I cards are the thinnest (about 3.3 mm) and were commonly used for memory expansion (e.g., SRAM/Flash). Type II cards are thicker (about 5.0 mm) and often used for modems or network adapters. Type III cards are thickest (about 10.5 mm) and used for miniature hard disks or other bulky devices. Therefore, Type I is the thinnest category.

Step-by-Step Solution:

Verification / Alternative check:

PCMCIA/PC Card spec sheets and laptop manuals confirm slot compatibility (a Type III slot can accommodate Type II/I, but not vice versa), reinforcing the thickness hierarchy.

Why Other Options Are Wrong:

• Only desktops: PC Cards were primarily for laptops.
• No longer produced/never existed: historically incorrect and self-contradictory.
• Have their own power source: cards draw power from the host slot.
• None of the above: incorrect because the thinnest statement is correct.

Common Pitfalls:

Confusing PC Card with ExpressCard or CardBus (which is an electrical upgrade but same form factor). Also mixing up Type II and III thicknesses.

Final Answer:

They are the thinnest of the PC Card types