Stored program machine

It is a general-purpose stored-program machine capable of processing very rapidly a large quantity of complex data (PX 3634A). Its general electronic equipment must comply with Specification MIL-E-16400... 

COLOSSUS was not strictly a stored program machine for the program was set by wiring plug-boards. The machine contained over 1500 thermionic valves (vacuum tubes), and it surprised everyone by its reliability and speed. It did not hold its data internally either, but on a loop of paper tape that was reread as necessary. Although the secrecy, required by the state for security... 

The fact that these calculators are ill suited to long sequential calculations is due mainly to the limited facilities associated with their small size and relatively low cost. To some extent this is not an inherent limitation, but it does not pay to increase the size of a punched-card calculator indefinitely without making a radical change in the basic structure of the machine. Such a change will bring us in the next section to the stored-program type of calculator. 

The very concept of a stored program computer had its roots in the work done during World War II on a computing machine called the ENIAC. At the start of World War II, the military felt a need for more and better trajectory tables for artillery. To prepare the tables, the Ballistic Research Laboratory of the U.S. Army Ordnance Department utilized a pair of mechanical differential analyzers. But by 1943 the produaion of ballistic tables was so far behind schedule that the Ordnance Department began to look for another means of preparing the tables. The answer came in April 1943, when a delegation from... 

The staff working in operations research, however, were impatient with the time it was taking to develop both the UNIVAC and the Institute for Advanced Study machine. They were able to convince the Air Force in 1948 to provide extra financing to the Applied Mathematics Laboratories in order to produce a very small computer to fill the need for computing power until either the Institute computer or the UNIVAC was ready. The complexity of the new design was kept to an absolute minimum so that it could be finished quickly. When it went into operation in May 1950, the SEAC (Standards Eastern Automatic Computer) was the first fully operational stored program electronic computer in the United States. ... 

Operations built into the computer and assigned order codes control the attached input-output equipment, perform the fundamental arithmetic, and transfer information from the memory to the arithmetic unit and back again. Selective replacement of partial words, i.e. the left or right address, allows the stored program to modify itself at the individual instruction level. Control of the machine is designed to proceed normally from address n in the memory to address m + 1 for its next instruetion pair. Consequently, commands are provided to transfer control to an arbitrary memory location... 

Floppy disk and floppy disk drive (Alan Shugart) Working at the San Jose, Cahfomia, offices of International Business Machines (IBM), Shugart develops the disk drive, followed by floppy disks to provide a relatively fest way to store programs and data permanently. 

By way of analogy, the ALU may be thought of as a super adding machine with its keys commanded automatically by the control signals developed in the instruction decoder and the control circuitry. This is essentially how the first stored-program digital computer was conceived. The ALU naturally bears little resemblance to a desktop adder. The major difference is that the ALU calculates by creating... 

In 1946, Max Newman (who had woiked with Flowers on Colossus) went on to estabhsh the Royal Society Computing Machine Laboratory at Manchester University, where with colleagues he built the world s first electronic stored-program digital computer, called the Manchester Baby, which was first operational in June 1948. Their development led to the world s first commercially available general-purpose electronic computer, called the Ferranti Mark 1. The first was delivered in February 1951. 

More specifically, the basic notions of a Turing Machine, of computable functions and of undecidable properties are needed for Chapter VI (Decision Problems) the definitions of recursive, primitive recursive and partial recursive functions are helpful for Section F of Chapter IV and two of the proofs in Chapter VI. The basic facts regarding regular sets, context-free languages and pushdown store automata are helpful in Chapter VIII (Monadic Recursion Schemes) and in the proof of Theorem 3.14. For Chapter V (Correctness and Program Verification) it is useful to know the basic notation and ideas of the first order predicate calculus a highly abbreviated version of this material appears as Appendix A. 

The program scheme PCS) we shall construct in Example VIII-6 has an extra test T which does not appear in S and which we assume to be an n+2-way test with possible outcomes 0,l,...,n, for some new symbol such a test could be simulated by binary tests in the standard way. Scheme P(S) has variables x, u, v, and z. Register z holds the eventual output and register x is input and program variable. The registers u and v are special program variables which simulate the pushdown store of a pushdown store machine implementing the computations of S. ... 

A bar code is a computer or machine-readable representation of information. It is usually made of dark ink on a light background to create high and low reflectance which is converted to Is and Os, when read by the computer program. A similar result may be achieved by patterns of dots, concentric circles, or text codes hidden within images. A bar code containing stored data in the widths and spacings of printed parallel lines or other patterns as... 

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