Search results
Results from the WOW.Com Content Network
The first prototype of the Therac-25 was built in 1976 and was put on the market in late 1982. The software for the Therac-25 was developed by one person over several years using PDP-11 assembly language. It was an evolution of the Therac-6 software. In 1986, the programmer left AECL.
Such incidents would not have been an issue in a single-use machine and unlike previous models, the Therac-25 relied on software rather than hardware safety interlocks. What happened was the operator using a keypad would select a particular mode. The machine would then start a programmed cycle and move plates into position.
There are exceptions, such as the Therac-25 accidents and the 1958 Cecil Kelley criticality accident, where the absorbed doses in Gy or rad are the only useful quantities, because of the targeted nature of the exposure to the body. Radiotherapy treatments are typically prescribed in terms of the local absorbed dose, which might be 60 Gy or higher.
A software bug is a design defect in computer software. A computer program with many or serious bugs may be described as buggy . The effects of a software bug range from minor (such as a misspelled word in the user interface ) to severe (such as frequent crashing ).
Between 1985 and 1987, a series of design flaws in AECL's Therac-25 medical accelerator caused massive overdoses of radiation [18] on 6 different occasions, resulting in five deaths. In 1987 the machine was found defective by the Food and Drug Administration (FDA) and eventually recalled by AECL despite their multiple denials that the problems ...
The DAO bug. On June 17, 2016, the DAO was subjected to an attack exploiting a combination of vulnerabilities, including the one concerning recursive calls, that resulted in the transfer of 3.6 million Ether – around a third of the 11.5 million Ether that had been committed to The DAO – valued at the time at around $50M.
MINC-11 – Laboratory system based on 11/03 or 11/23; [25] when based on the 11/23, it was sold as a 'MINC-23', but many MINC-11 machines were field-upgraded with the 11/23 processor. Early versions of the MINC-specific software package would not run on the 11/23 processor because of subtle changes in the instruction set; MINC 1.2 is ...
Nancy G. Leveson is an American specialist in system and software safety and a professor of Aeronautics and Astronautics at Massachusetts Institute of Technology (MIT), United States. [ 1 ] Leveson gained her degrees (in computer science, mathematics and management) from University of California, Los Angeles , including her PhD in 1980.