Silicon Chips

Computers these days are made out of many billions of electronic components. The most important of these components is the transistor. Invented at the end of the 1940s, transistors allowed people to build electronic circuits (and simple computers) that didn't use large, delicate components called "valves". Transistors helped people to build smaller, cheaper computers that were faster and used a lot less power.
It was in the final years of the 1950s that people found out how to put numbers of electronic components onto a small, thin sheets of an element called silicon. These pieces of silicon were called Integrated Circuits (or ICs), then referred to as Silicon Chips, and later they were just called "chips".

The Microprocessor

As people got better at making silicon chips they started to put more and more electronic circuits onto them.
The Intel 8086 microprocessor	The chips themselves were encased in a black, ceramic material with lots of metal 'pins' sticking out that would allow them to be soldered onto a circuit board. It was only a matter of time before people put enough electronic circuits onto a silicon chip to make a whole computer. This chip was called a Microprocessor: it contained the main parts of the central processing unit and it enabled people to make the small, fast computers that we use today.	Some Intel 80486 microprocessors
The first microprocessors were made in the early years of the 1970s by the Intel Corporation. The first microprocessor was called the 4004 - it was designed to be a general-puprose, programmable chip that could be used for many different jobs.

Answer these questions:

1. What electronic component replaced valves ? - transmitter transistor train-spotter
2. When were transistors invented ? - 1940s 1990s 1960s
3. What is an Integrated Circuit ? - a transistor lots of transistors on a sheet of hard, green plastic lots of electronic components on a sheet of silicon
4. Who made the first microprocessors ? - InterCity Intel Until
5. When were the first microprocessors made ? - 1970s 1980s 1990s
6. Why were transistors better than valves ? - they were a nice silver colour they were new transistors were cheaper and smaller
7. What element is mainly used to make Integrated Circuits ? - silver silicon selenium
8. Integrated Circuits were also known as what ? - silicon chips silicon slices fission chips

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Memory Chips

The new microprocessors were small and fast and they needed a way to store their data that was just as small and fast as them. Before silicon chips were popular the main memory of a computer was made up of a fine mesh of very thin wires that crossed over each other. These memory boards were called magnetic bubble memory: they were big, very delicate and didn't store a lot of data.
The silicon chip version of computer memory was much smaller and could store much more data.

ROM		Read Only Memory (or ROM) contains data that has been written once to the memory store but it can't be unwritten. Even if the computer is switched off or someone tries to save over the top of the data the original data in the memory store is safe. The ROM chips in the photo contain a special set of instructions called the BIOS (Basic Input Output Systems) which tell the computer how to 'talk' to the keyboard, monitor, etc. Without the BIOS even the Operating System can't load ... it is so important to the computer that it is stored on its own memory chip where it will always once the computer is switched on and won't be lost when it switches off again.
RAM		Once the computer is running it needs a lot of extra memory which it can use as "thinking space" ... such as storing the results of calculations when a spreadsheet is running. This memory does not need to be kept when the computer is switched off but it needs to be accessed quickly. This type of memory is called Random Access Memory (or RAM). The photo shows some Single Inline Memory Modules (or SIMMS) which contain a number of RAM chips on them. If you buy more memory for your computer (to make it go faster) this is what you get.
EPROM		Erasable Programmable Read Only Memory is halfway between ROM and RAM. Like ROM, it keeps its data when the computer is switched off .... ... however ... like RAM, you can delete this data and store new data over the top. On this type of EPROM you delete the data by shining an ultraviolet light onto the silicon chip. To allow you to do this, the ceramic has a little circular window of quartz put in that will allow ultraviolet light through. It also lets us see the silicon chip shining through the circle of quartz in the centre of the ceramic.

Answer these questions:

1. What is stored on memory chips ? - information data facts
2. What sort of memory was made out of criss-crossed wires ? - foamy memory fizzy memory bubble memory
3. What replaced the wire-based memory boards ? - silicon chips silver squares selenium chunks
4. What does RAM stand for ? - Really Ancient Memory Read Access Memory Random Access Memory
5. What is RAM used for ? - storing the results of calculations storing data when the computer is switched off keeping the computer cool
6. What does ROM stand for ? - Read Only Memory Random Only Memory Really Old Memory
7. What is ROM used for ? - storing the results of calculations storing data when the computer is switched off keeping the computer cool
8. What does EPROM stand for ? - extra pointy ROM extra programmable ROM erasable programmable ROM

You scored out of 8 on that test