Architecture and Hardware
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To increase reliability of transmission between magnetic tape and core storage on an IBM 7090/7094, blocks or records of data are often assigned a word called a logical checksum. This is a number derived from the block by some simple algorithm and as unique to it as possible. The method most commonly used to form a checksum is to add together every datum in the block by the ACL (add and carry logical) instruction.
Talk—a high-level source language debugging technique with real-time data extraction: 26
TALK, meaning Take A LooK, is a debugging technique which aids substantially in debugging complex real-time programming systems by interrupting the users program at desired points to extract previously specified data. The extracted data is later edited, listing the associated data with its high-level source language identification.
A method for comparing the internal operating speeds of computers
First, a table of frequencies of various types of operations is prepared based on experience in similar applications or, perhaps, on actual counts if these are available. Table 1 shows such a frequency table. Next, the total weighted execution time for a given operation type is obtained by multiplying the time required for the operation by the frequency count. Finally, an “average” operation time is calculated by summing overall operation types and dividing by the sum of the frequency counts. Table 2 shows the computation for the IBM 7090.
Table 3 shows a comparison of average and relative speeds for several current computers for the particular application using the IBM 7090 as a reference base.
Picture generation with a standard line printer
A method is described for producing gray-toned pictures on a line printer by utilizing the different degrees of blackness of standard print characters. Gray scales with 17, 32 and 64 levels have been devised. Scanned images of blood cells are used to display the technique.
Computer-usage accounting for generalized time-sharing systems
The current development of general time-sharing systems requires a revision of accounting procedures for computer usage. Since time-sharing system users operate concurrently, it is necessary to be more precise as to the amount of computer time and storage space that a user actually utilizes. The various cost factors which should be considered for computer usage accounting in generalized time-sharing systems are discussed.
The FORTRAN II CHAIN feature on the 7090 can be used to save card-to-tape time, loading time, and to provide a convenient method for storing and transporting producting programs. The method is simply to load the desired program as a CHAIN and save the tape on which it is stored. A trivial program can then be used to recall the major program.
report on CCITT data communications study group meeting
Data communications was the subject of a two-week meeting held 24 September through 4 October 1963, in Geneva, Switzerland, by the International Telegraph and Telephone Consultative Committee (CCITT) Special Study Group A. Previous meetings of this group had been held in Geneva in April, 1960, and October, 1961. The CCITT has traditionally been responsible for all standardization activities involving the public telecommunications network of the world. Among the 150 participants, there were eleven USA representatives who represented the Government, various business machine companies and the common carriers.
Some effects of the 6600 computer on language structures
The problem of compiling efficient 6600 codes prompted the development of an intermediate language reflecting the structure of the machine, that is more easily manipulated in improving object program efficiency. The subject of this paper is the intermediate language and methods of manipulating it.
Compilations of a series of arithmetic statements are discussed. It is assumed that all functions and exponentials have been removed from these statements, and replaced by simple variables. For purposes of simplicity the treatment of subscripts is ignored.
A simplified 6600 structure is presented to illustrate the compiling method. Several assumptions are made for purposes of simplification, although there are cases in which the assumptions are violated in the actual machine.
A programming package for some general modes of arithmetic
An interpretive programming package is described for computation with operands which may be real, complex, single or double precision, or real multiple precision. It also performs operations on matrices formed from these elements. A simple language structure is used to describe the computation.
Use of the disk file on stretch
The paper begins by briefly describing the Stretch (IBM 7030) computer with special emphasis given to the organization and operation of its input-output equipment. Physical characteristics of the two-disk system (4,194,304 72-bit words, 8 µsec-per-word transmission rate, etc.) are noted. Timing limitations due to arm motion and disk rotation are discussed.
Applications of disk usage are discussed separately for problem programs and for systems programs such as compilers and the supervisory program. Approximately 260,000 words of disk storage are reserved for the storage of systems programs and the subroutine library. Problem programs, however, are not currently filed on the disk.
Certain programming techniques are discussed for transmitting words between disk and core storage with minimum delaying and interruption of the arithmetic unit. Dumps on disk are considered for both recovery from computer malfunction and for mathematical or physical developments during the calculation.
Recent contributions on the subject of counting the ones or reversing the digits of a binary word have prompted some rather more general observations on bitwise operations which treat each binary digit in a computer word as a separate entity.
The BKS system for the Philco-2000
The BKS System is a program sequencing system designed for the Philco-2000 computer to meet operational requirements of the Bettis and Knolls Atomic Power Laboratories. The Philco-2000 on which this system is being used has a 32,768-word memory, 16 tape transports on-line, and an electric typewriter on-line. The card-to-tape, card-to-printer, tape-to-card, tape-to-printer, and routine tape-to-tape operations are performed with off-line equipment.
A card format for reference files in information processing
This paper proposes a card format suitable for a variety of reference files in information processing. An 80-column IBM card is divided into two fields—reference material field (columns 1-67) and identification field (columns 68-80). The format for the reference material is flexible, while the format for the identification is rigid. The reference material includes basically an index, title, source, class, summary and cross reference for each entry. The identification includes basically codes for a matrix of descriptors, an entry number, and the kind, major interest, and source of the reference. The identification also provides a choice to identify material for personal as well as general files. Since this card format is sufficient to identify the material normally associated with reference files for books, articles, programming terms, hardware terms, equipment, machine systems, abbreviations, etc., it is suitable as a standard for card reference files in information processing.
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