Errata to "Atomic shared register access by asynchronous hardware," FOGS \´86

The authors report that the paper by P.M.B. Vitanyi and B. Awerbuch, "Atomic shared register access by asynchronous hardware," Proc. 27th IEEE Symp. on Foundations of Computer Science (1986), 233-243, has an error in the \´Struldbrugg\´ algorithm (the main bounded tag algorithm) and a counterexample is presented. The "selection rule" of the reader is not sufficient to guarantee atomicity, but only the weaker regularity condition. Informally, regularity for multiwriter registers means that a reader does return a value written by a write, such that there is no complete other write strictly in between the durations of the read and the write it returns.