Memory modules – Identifying a 30-pin module type If a motherboard RAM slot has 30 pins, which type of memory module does it accept?

Introduction / Context:
Different memory generations use distinct physical form factors. Accurate identification by pin count prevents installation errors and aids in supporting legacy systems.

Given Data / Assumptions:

• Slot has exactly 30 contacts (pins).
• We refer to classic desktop modules, not proprietary laptop SODIMMs.
• No adapters used.

Concept / Approach:

Early PCs (late 1980s–early 1990s) used 30-pin SIMMs for FPM/EDO DRAM. Later, 72-pin SIMMs appeared, followed by 168-pin SDRAM DIMMs, and then DDR generations with 184/240 pins, etc. Therefore, a 30-pin slot indicates a 30-pin SIMM.

Step-by-Step Solution:

Verification / Alternative check:

Mechanical keying prevents other module types from inserting. Motherboard documentation for vintage systems confirms 30-pin SIMM support.

Why Other Options Are Wrong:

DIMMs have far more pins; SDRAM DIMMs are 168-pin and incompatible. “All of the above” is clearly incorrect given mechanical mismatches.

Common Pitfalls:

Confusing 30-pin SIMM with 72-pin SIMM; assuming all “SDRAM” are DIMMs—some late SIMMs carried EDO DRAM, not SDRAM.

Final Answer:

SIMM (30-pin Single Inline Memory Module).