Research and Advances

The valuable “Survey of Punched Card Codes” prepared by Smith and Williams (Comm. ACM 3, Dec. 1960, 638) unfortunately omits the card codes of European equipment, other than IBM. These are presented in the table on page 181. This information has been extracted from a Ferranti publication, “Collected Information on Punched Card Codes” (List CS 266) and has been set out in much the same way as the table by Smith and Williams.

The Leviathan studies are investigations into how people operate in large social organizations. Examples of such groups are a large military command, a governmental agency like the U. S. Bureau of Internal Revenue, or an industrial combination like an international oil corporation.

In a previous paper [1], B. Dimsdale and I reported on the use of programmed Hamming codes for error correction on a 7090. The paper generated much interest, but several readers remarked that they could not use the technique on their decimal machines since they could not manipulate the bit structure of the characters. This paper presents a modification of Hamming's technique to adapt it to such machines. It generalizes to any number base for which addition is built into the machine, and so could be used for alphabetic error correction on a machine where such operations as (A + B, literally) or (R+2, literally) or (H + $, literally) are unequivocally defined. The technique will be described for single strings of characters, but may be generalized to parallel techniques if parallel, no-carry addition is available on the machine in question.