History
Early computers sometimes required the use of parity RAM, and parity-checking could not be disabled. A parity error typically caused the machine to halt, with loss of unsaved data; this is usually a better option than saving corrupt data. Logic parity RAM, also known as fake parity RAM, is non-parity RAM that can be used in computers that require parity RAM. Logic parity RAM recalculates an always-valid parity bit each time a byte is read from memory, instead of storing the parity bit when the memory is written to; the calculated parity bit, which will not reveal if the data has been corrupted (hence the name "fake parity"), is presented to the parity-checking logic. It is a means of using cheaper 8-bit RAM in a system designed to use only 9-bit parity RAM.
Read more about this topic: RAM Parity
Famous quotes containing the word history:
“... in America ... children are instructed in the virtues of the system they live under, as though history had achieved a happy ending in American civics.”
—Mary McCarthy (19121989)
“Both place and time were changed, and I dwelt nearer to those parts of the universe and to those eras in history which had most attracted me.”
—Henry David Thoreau (18171862)
“We said that the history of mankind depicts man; in the same way one can maintain that the history of science is science itself.”
—Johann Wolfgang Von Goethe (17491832)