Memory Circuits
Why Is Memory Important?
Simulations
One Nybl Memory
Four Nybl Memory
Steering Circuits
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Why Are Memory Circuits Important?

        Shame on you for asking that question.  Surely you know the following.


Memory Circuits - An Introduction

        We'll start with a simulation of a simple memory.  The simulation demonstrates several - but not all - aspects of memory operation.


Simulation

        In this simulator you can set four bits of data (using the small red buttons to set each bit), and then you can store the data in the memory by "clocking" it in.  In the simulator below do the following.


A Short Note About The Four Bits Above

        One interesting thing about the four bit memory above.  Memory usually comes in bytes.  A byte is eight bits.  The memory register above only has four bits, so it is half of a byte.  Strangely enoungh, there is a name for four bits of memory.  Since it is half a byte, the name assigned to four bits of memory is a nybl.  Although we make a few jokes here and there through these lessons, it is true (albeit a little funny) that a nybl is half of a byte - and they are both spelled with a "y".


        When you buy memory in a computer, you specify things like how much RAM (Random Access Memory) you want the computer to have.  You might want to have 512 Megabytes, for example.  We can't simulate that large a memory, so we will try something smaller.  In the next simulation we give you a four nybl memory.  It's just large enough that you can experiment with it, and you can give yourself a mental model of how larger memories work.
Simulation

        In this simulation, you can work with a four nybl memory.  Note the following about this simulation.


Exercise

        In the simulation above, set 1001 into memory element 2.  As you do that, assume the the lowest bit is the LSB and the highest bit is the MSB.


Steering Circuits - Under Construction
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