COMPUTER ARCHITECTURE AND THE CYNAIDE COATED APPLE

FATHER OF THEORITICAL COMPUTER SCIENCE AND ARCHITECTURE FORMALISATION OF CONCEPTS OF CONCEPTS OF ALGORITHM AND COMPUTATION WITH TURING MACHINES – A MODEL OF GENERAL PURPOSE COMPUTERS

Entscheidungsproblem DAVID HILBERT DECISION PROBLEM A STATEMENT IS VALID ONLY IF IT CAN BE DEDUCED FROM AXIOMS VALIDITY OF PROPOSITIONS FIRST ORDER LOGIC ALGORITHM UNIVERSALLY VALID?

IT’S RAINING WHEN IT IS RAINING. IT’S RAINING WHEN IT IS NOT RAINING. WHAT IS COMPUTABLE? ALONZO CHURCH + ALAN M TURING: “SOLUTION TO DECISION PROBLEM IS IMPOSSIBLE.”

TURING MACHINE Can mathematically describe any operation a computer can perform using a few rules 1936 Not physical...abstract mathematical objects Applications in math and C.Sc as simple yet powerful explanatory tools Can describe infinitely many operations, though not every conceivable one Developed in the process of solving Entscheidungsproblem Its implementation...led to stored program concept

Alphabets Tape Alphabets STRIP OF TAPE: TAPE/MEMORY PARTS: It is of infinite length and divided into an infinite number of cells. Holds a character/symbol replaced by the read/write head ... ... Read/write head cell Input During an operation, the tape can move or not at all to adjust the head. > 1 0 1 1 0 < ... ... Start End Blank Space Alphabets Tape Alphabets Σ = {0,1} Ґ = Σ U { >, < , ~ )

Tape- input /output device and storage medium for information States:

A state register that stores the state of the Turing machine, one of finitely many. Among these is the special start state with which the state register is initialized. These states, writes Turing, replace the "state of mind" a person performing computations would ordinarily be in. A finite table[19] of instructions[20] that, given the state(qi) the machine is currently in and the symbol(aj) it is reading on the tape (symbol currently under the head), tells the machine to do the following in sequence (for the 5-tuple models): Either erase or write a symbol (replacing aj with aj1), and then Move the head (which is described by dk and can have values: 'L' for one step left or 'R' for one step right or 'N' for staying in the same place), and then Assume the same or a new state as prescribed (go to state qi1)

Led to the development of modern computers ... ... Read, write and move... ... ... In computer science, a universal Turing machine (UTM) is a Turing machine that can simulate an arbitrary Turing machine on arbitrary input. The universal machine essentially achieves this by reading both the description of the machine to be simulated as well as the input thereof from its own tape. Alan Turing introduced this machine in 1936–1937. This model is considered by some (for example, Martin Davis (2000)) to be the origin of the stored program computer—used by John von Neumann (1946) for the "Electronic Computing Instrument" that now bears von Neumann's name: the von Neumann architecture.

SOLUTION TO THE HILBERT DECISION PROBLEM HALTING PROBLEM ENTSCHEIDUNGSPROBLEM UNDECIDABLE FOR TURING MACHINES

AUTOMATIC COMPUTING ENGINE AT BLETCHLEY PARK AUTOMATIC COMPUTING ENGINE AT BLETCHLEY PARK...AN IMPLEMNTATION OF THE UNIVERSAL TURING MACHINE

YOGA FOR YOUR PATIENCE LEVELS....A SHORT VIDEO FOLLOWING WHICH I WILL THANK ALL OF YOU