COMPUTING HISTORY — CPU in the Altair 8800 The Central Processing Unit is an embedded chip that acts as the “brain” of a computer. Which Intel processor powered the Altair 8800, one of the earliest influential personal computers?

Introduction / Context:
The MITS Altair 8800 (mid-1970s) ignited the personal computing revolution by offering an affordable, build-it-yourself microcomputer. Identifying its CPU provides historical context for later platforms like the Apple II and IBM PC.

Given Data / Assumptions:

• We must choose the specific Intel CPU model used in the Altair 8800.
• Several period-correct chips existed, but only one was the Altair’s standard processor.
• Some distractors are real CPUs from other systems or eras.

Concept / Approach:
The Altair 8800 shipped with the Intel 8080, an 8-bit microprocessor that significantly improved performance over the earlier 8008. It became the basis for CP/M systems and inspired generations of hobbyist computing.

Step-by-Step Solution:
Recall historical fact: Altair 8800 → Intel 8080.Eliminate lookalike part numbers not used in the Altair.Select 8080 as the correct answer.

Verification / Alternative check:
Contemporary documentation and museum archives list the Intel 8080 as the default Altair CPU (with optional Z80 upgrades appearing later in compatible machines).

Why Other Options Are Wrong:
6502 — used in Apple II, Commodore 64, Atari 8-bit; not the Altair.6400 — not a standard microprocessor for this system.8286 — number resembles the 80286 (a later 16-bit CPU); not applicable.4004 — Intel’s early 4-bit CPU, predating the Altair’s architecture.

Common Pitfalls:
Confusing the Altair with later 8086/80286 IBM PC family machines. The Altair predates them and used the 8-bit Intel 8080.

Final Answer:
8080