Research and Advances

Two subroutines for symbol manipulation with an algebraic compiler

The current University of North Carolina version of the IT Compiler [1, 2], as well as the GAT Compiler of Arden and Graham of the University of Michigan [3], have special “alphabetic read” and “alphabetic type” statements. On the UNIVAC 1105 these features allow the direct input or output of six-symbol words, each symbol being either an alphanumeric or special character. Internally, each symbol is represented by a six-bit binary coded decimal code. On the IBM 650, five-symbol words are processed, with each symbol represented internally by a two-digit decimal code.
Research and Advances

On finding minimum routes in a network with turn penalties

In some highway engineering work it is necessary to find a route between two points in a city's street and freeway network such that a function of time and distance is minimized. Such a route is called a “best” route, and finding such a route is not a difficult task. The Moore Algorithm1 accomplishes this quite nicely, and using that algorithm and a procedure developed by Hoffman and Pavley2 (programmed by them for the IBM 650) it is even possible to find the “Nth best path.”
Research and Advances

Comment on a paper on parallel processing

The article by Lynn Yarbrough on Parallel Processing in the October Communications is interesting since it attracts attention to a subject which needs to be given increased consideration. His indictment of manufacturers for failing to provide what he feels is minimal to realizing the advantages of multi-programming is not applicable to STRETCH, however. It may be recalled that his specific complaint concerns the lack of protection of any program or monitor from the unpredictable actions of any other program. On page 15 of the STRETCH Data Processing System Reference Manual, we read: Address monitoring facilities are provided … The upper and lower boundaries of the storage area to be defined are placed in two address boundary registers. An alarm will be given when an address falls either inside or outside the defined area, whichever is desired. Storing in protected areas is normally suppressed.

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