William D. Munro

Targeting capital: A cultural economy approach to understanding the efficacy of two anti-genetic engineering movements.

In the late 1990s, the British anti–genetic engineering (GE) movement effectively closed Britain’s market for genetically modified foods, while the U.S. anti‐GE movement had a negligible impact. In seeking to explain the different outcomes of these similar social movements, the authors draw upon the global commodity chains (GCC) literature to extend the understanding of the economic and industry‐related openings and closures social movements face as they seek to promote social change. This analysis not only illustrates the importance of economic structures and organization for movement outcomes, but also shows how the economic sphere is culturally constituted. In this fashion, it broadens the social movement literature’s understanding both of the way that political economy matters to movement efficacy and of the way that cultural processes infuse the economic sphere. The study advances the GCC literature by showing how GCCs are cultural as well as economic constructs.

Scaling Machine Arithmetic

A general approach to the problem of scaling machine arithmetic is developed. This leads to the determination of inequalities that can serve as a basis for the derivation of systematic scaling techniques. The inequalities and techniques are shown to apply to complement arithmetic with either integral or fractional machine operations and to absolute value and sign arithmetic for both types of operations. A detailed discussion is presented for the case of complement integer arithmetic. The connections with floating point arithmetic are derived.

Fixed and Floating Point Arithmetic; Scaling

This chapter elaborates describes fixed and floating point methods of computing and some of the arithmetic operations related to them. Fixed-point operations in a digital computer treat all sequences of digits representing arithmetic operands as though an imaginary base point were in a fixed position. Shifting operations are designed to move the digits in a register either to the right or to the left of their initial position. The CDC 1604 left shift instructions are end around or circular. The multiply integer and divide integer operations treat sequences of digits as though the binary point were at the right-hand end of the sequence. In a machine using integral fixed point operations, all arithmetic operations are carried out on integers with the base point considered to be at the right-hand end of each sequence of digits. If the sum or difference is formed in an arithmetic register of extra length, the arithmetic register may accommodate it but an ordinary storage register may not. The direct application of fixed-point arithmetic instructions to floating point machine operands will produce incorrect results.

Assembly of Complete Programs

This chapter discusses the assembly of complete programs. Many assembly programs that go beyond the regional in their capabilities often prepare an intermediate version, in regional form, of the programs they are putting together. The SURAP type of assembly program employs a format that gives the region tag in numerical form. Each program for assembly must be initiated by a Program Name statement and be terminated with an End statement. The subroutine INTERP is entered by a return jump to the symbolic address INTERP from the upper instruction of a program step in the main program. The INTERP program itself is a subroutine of the program from which it draws the interpretive instructions that it interprets and executes.

CHAPTER 3 – Elementary Coding

Publisher Summary This chapter focuses on elementary coding, which represents the number of instructions that are arranged into meaningful patterns in such a way that the computer is made to perform a given calculation. The coding technique that should ordinarily be employed consists of creating the instructions for handling each item of data as it is needed from a small set of prototype instructions. An iterative loop of addresses consists of a sequence of addresses that the control consults repetitively in the execution of a code. If a program causes the computer to carry out on the same data exactly the same calculation every time it is executed, its initial address will be called a proper entry point for the program. The coder should not blindly set out to write a program without working out a precise plan of attack beforehand. An index register to index register transmission can be carried out by means of an appropriate combination of the store index and load index or enter index instructions.

CHAPTER 5 – Nonarithmetic Operations

Publisher Summary This chapter focuses on certain aspects of nonarithmetic operations. The stop instructions in the CDC 1604 operate as unconditional jump instructions. In explicit computers, each instruction includes a jump, that is, each instruction contains the location of the instruction which is to follow. An instruction such as the sign jump specifically tests the single sign bit. In a computer, the basic operation of forming a logical product or sum is usually utilized in a number of related operations giving specialized combinations of logical and transmissive, complementing, and arithmetic instructions. In the CDC 1604, there are several instructions that facilitate the problem of dealing with individual bits in a register. A basic problem that often arises in programming is that of selecting a quantity with a given property from a set of stored data. The names equality search and threshold search reflect the fact that the basic conditions are the same.

CHAPTER 2 – Machine Organization

Publisher Summary This chapter discusses the way in which computing machines are organized to perform their functions. The number of digits that constitute the content of a register defines the length of that register. In the CDC 1604, all storage registers are 48 bits in length. The word in a storage register, when interpreted as an arithmetic operand, is usually considered to be either a fraction or an integer, in which case the base point is thought of as fixed or it is thought of as a combination of the two. The accumulator is utilized in almost all of the arithmetic instructions of the computer. If a sequence of digits is to be interpreted as an instruction, it must contain minimally a means of specifying the particular operation to be performed. If operands are involved, they must also be specified. The CDC 1604 instruction word is made up of 24 bits. Because instructions and operands occupy the same set of storage registers, they are indistinguishable. The amount of peripheral input–output equipment used by a CDC 1604 varies in different installations.

CHAPTER 7 – Input-Output

Publisher Summary This chapter discusses the mechanics of input and output with some specific examples. For the experienced programmer, the choice of a particular input–output equipment and format depends on personal preference, speed of operation, and the magnitude of the problem. The normal exchange of data is with relatively slow peripheral equipment and is geared to the particular rate of the device in use. While the octal content of a register is not desirable for results in most instances, it is most useful in the early stages of checking out programs. A unit of input or output information consists of a linearly ordered array or string of characters chosen from some admissible set of characters. A floating point decimal number is a fixed-point decimal number. A Hollerith sequence is composed of a sequence of alphabetic characters, special characters, digits, and blanks.

CHAPTER 1 – Number Systems

Publisher Summary This chapter discusses a number system, which is a scheme for representing positive integers. The system that human beings have used most is based on the integer 10, presumably because people have 10 fingers or digits. All the digit-by-digit algorithms for arithmetic have the same form in any base as they have in decimal. Although many digital computers use a mode of arithmetic in which all sequences of digits are interpreted as integers, others are so designed that all such sequences are interpreted as fractions. The number of significant digits retained determines the accuracy of the rounded-off number. If simple truncation of the sequence is used, an accuracy that depends on the base and the number of digits used are obtained.

CHAPTER 6 – Subroutines

Publisher Summary This chapter describes a subroutine as an auxiliary routine used in conjunction with, but not as part of, the main routine or main program. Individual computers vary according to the methods by which a return jump is achieved. In some machines, the repertoire of instructions includes a return jump instruction in which both the jump address and the location at which the return address is to be stored are implicitly understood. The computer carries out the assembly operation under the control of an assembly program. SURAP selects the named subroutine from its permanent storage location in the library, which is probably on a magnetic tape, and provides a copy of it in assembled form.