Page 23 - UNI 101 Computer Science Handout.

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and output devices that are frequently seen as part of computer systems. The diagram in below Figure

actually applies equally well to large mainframe computers, small personal computers, and even devices

with computers embedded in them, such as PDAs, iPods, GPSs and cell phones. Large and small
computers differ primarily in speed, capacity, and the selection of peripheral devices provided. The basic

hardware components and design are very similar.

https://www.youtube.com/watch?v=SSnNY8GfZig

2.1.1.1 Central Process Unit

Conceptually, the CPU itself is often viewed as a composition of three primary subunits:

1. The arithmetic/logic unit (ALU) where arithmetic and Boolean logical calculations are performed.

2. The control unit (CU), which controls the processing of instructions and the movement of internal

CPU data from one part of the CPU to another.

3. The interface unit, which moves program instructions and data between the CPU and other

hardware components.

(In modern CPUs, the actual implementation is usually modified somewhat to achieve higher
performance, although the basic concepts are carefully preserved.

23 Academic Year 2025/2026