April 26, 2018 Thursday
Bedtime Story
Note B of Ada Lovelace - Part 6
Tonight we shall continue with the Note B
of Ada Lovelace wherein she is describing how the Operation-cards and
Variable-cards will be interacting with the vertical columns of discs to operate
on a mathematical function.
Here she is also describing how these
vertical columns can act as temporary storage of working data, something that
in today’s computers is performed by dynamic random-access memory integrated
circuit using micro capacitors that can either be charged or discharged.
“There are two varieties of the Supplying
Variable-cards, respectively adapted for fulfilling two distinct subsidiary
purposes: but as these modifications do not bear upon the present subject, we
shall notice them in another place.
In the above case of axn, the
Operation-cards merely order seven multiplications, that is, they order the
mill to be in the multiplying state seven successive times (without any
reference to the particular columns whose numbers are to be acted upon).
The proper Distributive Variable-cards step
in at each successive multiplication, and cause the distributions requisite for
the particular case.
For xan the operations would be 34 (x)
For a . n. x the operations would be (x, x) or 2 (x)
For (a/n).x the operations would be (
,
x)
For a + n + x the operations would be (+, +) or 2(+)
The engine might be made to calculate all
these in succession.
Having complete axn, the
function xan might be written under the brackets instead of axn,
and a new calculation commenced (the appropriate Operation and Variable-cards
for the new function of course coming into play).
The results would then appear on V5.
So on for any number of different functions
of the quantities a, n, x.
Each result might either permanently remain
on its column during the succeeding calculations, so that when all the
functions had been computed, their values would simultaneously exist on V4, V5,
V6 etc; or each result might (after being printed off, or used in any specified
manner) be effaced, to make way for its successor.
The square under V4 ought, for the latter
arrangement, to have the functions axn, xan, anx, etc and
successively inscribed in it.
Let us now suppose that we have two
expressions whose values have been computed by the engine independently of each
other (each having its own group of columns for data and results).
Let them be axn, and bpy.
They would the stand as follows on the
columns:-
Stay tuned to the voice of an average story storytelling
chimpanzee or login at http://panarrans.blogspot.com
Good night mon ami and my fellow cousin ape.
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Another great educator and a teacher that I am aware of is
Professor Subhashish Chattopadhyay in Bangalore, India.
While I narrate stories, Professor Subhashish an electronic
engineer and a former professor at BARC, does and teaches real mathematics and
physics.
He started the participation of Indian students at the
International Physics Olympiad.
Do visit him here:
All his books can be downloaded for free through this link:
For edutainment and English education of your children, I
recommend this large collection of Halloween Songs for Kids:
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