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Computer Organization & Architecture

Foundations of Computing7

Instruction Set Architecture5

Datapath & Control Unit4

Instruction Pipelining4

Memory Hierarchy7

I/O Interfaces & Interrupts5

How does the CPU even talk to a keyboard or a screen?
Interrupts: letting the device tap the CPU on the shoulder
What happens when two devices interrupt at the exact same time?
DMA: letting devices copy data without bothering the CPU at all
Polling vs interrupts vs DMA - choosing the right tool

Boot to Execution: The Full System Trace5

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Computer Organization & Architecture

Foundations of Computing7

Instruction Set Architecture5

Datapath & Control Unit4

Instruction Pipelining4

Memory Hierarchy7

I/O Interfaces & Interrupts5

How does the CPU even talk to a keyboard or a screen?
Interrupts: letting the device tap the CPU on the shoulder
What happens when two devices interrupt at the exact same time?
DMA: letting devices copy data without bothering the CPU at all
Polling vs interrupts vs DMA - choosing the right tool

Boot to Execution: The Full System Trace5

Learn Computer Organization & Architecture I/O Interfaces & Interrupts

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How does the CPU even talk to a keyboard or a screen?

A keyboard isn't memory, but the CPU still needs to read from it. Here's the simple trick that lets the exact same LOAD/STORE instructions talk to any device at all.

9 min readUpdated 2026-09-03computer-architectureiomemory-mapped-io