Now we can understand a little better
About design of modern computer
This standard design was given
By the great Dr von Neumann. and his team .
This was seventy years back.
The main parts of the “von Neumann”design
Are the ALU and the CPU
And the most important “Main Memory”
Which is a Magnetic Memory board
Fixed inside the machine much like black board
We see in school rooms for writing any thing.
The Main Memory was indeed the most wonderful lpart.
The ALU was a sophisticated version
Of the first jumble of flip flops
And registers used by the researching engineers
when they produced thefirst calculator..
It solved big mathematical problems no doubt
But the human engineer had to control
Every little action every second
Sitting before the system day and night.
The CPU is the commander- in- chief
It has taken the place
Of the outside human engineer.
But it is nothing but a group of“Registers”
It gets from the human engineer
Most accurate coded “instructions”,
Like the working steps we write
To solve in algebra a bigproblem.
The CPU is however only a slave.
It is abject slave of the human engineer!
It switches on all electrical circuits
And the mathematical circuits
As per a strict plan and sequence
Prescribed by the human engineer.
It promptly responds to the signals
Coming from all computer’s parts
As per the human engineer’s prerecorded plan.
Now, where does the computer record
The instructions given by the human engineer?
Here we understand the great value
Of the indispensable “Main memory”
That Magnetic memory board
Of those ancient first computers.
It is just like the class room black board.
Used in every school in every town.!
The magnetic memory board
Of the ancient computers
Invented by Dr von Neumann
comprised of thousands of tiny electro magnetic rings
In perfect rows and columns
Looking like a graph paper
The rings were connected into groups
Of eight or sixteen rings
To represent the eight or sixteen digit codes
Of the numbers on which mathematical
And logical operations are done.
As long as computer is not switched off
Each tiny ring individually
Can be magnetized or demagnetized.
by sending currents
Through the invisible hidden wires!
Currents in vertical wire magnetized the ring
The horizontal wire demagnetized.
Thus they indicated the Boolean zeroes and ones.
The eight or sixteen chamber magnetic houses
Can indicate codes of numbers
Exactly like the electrically constructed registers
These magnetic rings help construct
Magnetic houses (much like the registers)
Each having a row of eight or sixteen rooms
The plastic frames used have thousands of the rings
Arranged in perfect rows and columns
Forming houses of eight or sixteen rooms.
There is another very important thing
The eight or sixteen bit electric codes
Which represent the numbers
Loaded in the registers can flow
Through the electric superhighways
Into the magnetic memory houses.
In the reverse way copies of the magnetic codes
Contained in the magnetic memory houses
Can be converted into electric pulses
And can flow into the registers
To represent the same number in electric code.
Suffice it to say that every number
In the form of its eight bit or sixteen bit code
Could flow very easily between CPU,
The ALU and the magnetic memory houses
Existing on the Main Memory.
There are different type super highways
Between different parts .
Data (that is, the eight bit or sixteen bit codes)
Can move only on these superhighways
And not by any alternate path..
In the first computers of Dr von Neumann
There was even a forty lane superhighway between
Main memory and the forty chamber “Data Register”
But the forty chamber “Data Register “
Was actually a row of four separate registers
Of eight, twelve, eight and twelve flip flops
Separately grouped in that order.
The forty bit incoming instruction
Automatically broke into four small instructions
And each instruction went its separate way
In to the smaller register..
Thus any digital code can flow,
While travelling inside the computer,
Only through the prescribed super highways.
It can be between registers in ALU and CPU .
And the “magnetic houses”of the “Main Memory”
(also from the inputtingand to the outputting devices.)
Only the connecting superhighways should be used.
The zeroes and ones can not spill out
Like ping pong balls running all over the floor.
Such was the rigid and high discipline
Even in the ancient computers of seven decades back