Software Craftsmanship

Go Back

Computer Hardware and Software

Posted by Tom Spencer on 2019-12-26

A computer is not that different from a toaster. Like a toaster we put something into a computer like 2 + 2 and then we wait a while and get a result.

The computer is split between input and output devices for example the monitor is output and keyboard is input.

The power supply in a computer is important in that it takes power from the electrical outlet and spread it around the computer. There are modular power systems which can make your computer more organised. The motherboard has slots which allows us to connect peripherals such as memory cards. The bios or chip needs some information about what is connected and what time it is. There is also an area where you can connect your speakers. Everything connects to the motherboard. There is also a CPU or Central Processing Unit which is a big brain. All it does is think. CPUs come in Herzt 2.5 GH. It gets hot and needs a way to stay cool. The heat sync does this. It keeps the CPU cool. The CPU is very smart but has no memory.

The hard drive acts as the memory of the computer. The clatter spins. All the software is stored on the hardware. It is the computer’s long term storage. There are hard disk drives but also solid state drives.

The computer also needs short term memory. This is where RAM comes into play. RAM stands for Random Access Memory.

Relationship between hard drive and RAM

We can think of library books as hard drive and a desk as RAM.

At any time we can grab a book. We can put it on the desk and read from the book. The bigger the desk is the more things we can have on it at the same time. The more space I have the more I can do at the same time. The more storage the RAM has the more I can do at the same time. For instance we may want to play a game, have Intellij open and then also chrome to look at some sites.

The monitor uses a video card. It has an output to send the signal to the monitor. We can also find integrated video cards which are integrated with the motherboard. We can also have sound cards and network cards which are sometimes connected to the mother board.

There is also a CD, DVD, Blue Ray drive which is designed to play disks.

Laptops have all the same stuff as above but are packed more closely.

We can now also look at software.

Software is a series of instructions or data stored on the computers hardware recorded as 1s and 0s for offs and ons. By putting 0s and 1s together in a sequence we give them meaning.

An example of using this system to communicate might be to think of the possibilities inheritent in two lights. Both lights off could signify go to sleep. 1st light on might signify scratch your head. 2nd light on might signify wiggle your nose. Both on could mean jump and down on the spot.

Having 8 bits is equal to a byte. We might show this through 8 LEDS each representing a byte of information. For instance the keyboard char is byte of information

0 1 0 0 1 0 0 0 = h 0 1 1 0 1 0 0 1 = i

Hi on keyboard sends 2 bytes of information to the computer.

Solid state drive uses electrons. When the cells are empty it represents 0. When it is full it represents 1.

MP3s contain 3.5 megabytes data 3.5 million bytes 28 million bits - 28 million ons and offs in one MP3. 1 minute of video on iPhone is 177 megabytes 177 million bytes 1.4 billion bits 1.4 billion ons and offs to store video on iPhone. Blue Ray video can contain 16 gigabytes of data 16 billion bytes 128 billion ons and offs.

If every star in the Milky Way galaxy was the equivalent of one bit. We would have 37 billion bytes of data in Milky Way. This gives you a sense of the amount of information contained by hardware.