Page 24 - UNI 101 Computer Science Handout.

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Figure 1 Workstation

The interface unit interconnects the CPU with memory and also with the various I/O (input/output)
modules. It can also be used to connect multiple CPUs together. In many computer systems, a bus

interconnects the CPU, memory, and all of the I/O components. A bus is simply a bundle of wires that

carry signals and power between different components. In other systems, the I/O modules are

connected to the CPU through one or more separate processors known as channels.

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

2.1.1.2 Memory

Today’s software places tremendous demands on all components of a computer system. Forty years

ago, an IBM mainframe computer was supplied with a maximum of 512KB of primary memory. The
performance of this machine was measured at 0.2 millions of instructions per second (MIPS). Today, a

personal computer or personal digital assistant with that level of performance would be considered

unusable for most applications. It wouldn’t even be adequate for a cell phone! Graphics and multimedia
applications, in particular, require performance far in excess of previously acceptable levels. Most

modern computers perform at levels of a billion instructions per second or more. Supercomputers can

perform trillions of instructions per second! There is a continuing demand for higher and higher levels

of performance, driven by the desire to solve complex problems that require more computer power, as

well as by market needs and by competition. As you’ll see, we’ve even learned to tie computers together
into massive networks and clusters and grids to accumulate even more computer power for the massive

problems that require ever-increasing computer capability: sophisticated problems in physics, weather

analysis, searches for medical cures, complex financial, economic, and business analyses, even the
search for extraterrestrial intelligence.

Obviously, individual components—CPU, memory, I/O modules, and the connections between them

have been optimized to maximize computer system performance. Considering the system as a whole

24 Academic Year 2025/2026