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In his account of the history of the Apollo Guidance Computer, Don Eyles describes the role of a parity bit as follows (p. 80):

... if one of those hair thin wires in our woven core-rope memorycore-rope memory happened to break, a parity failure might occur. Each of our fifteen-bit words of memory actually had an additional, sixteenth bit, called the parity bit, which the assembler set to a one or a zero to force the total number of ones among the 16 bits to be odd. When the computer accessed a word of memory it counted the bits that were set to one and if the result was not an odd number it would trigger a restart.

I understand how parity is working here to detect the broken wire; but it's not clear to me what restarting accomplishes. If the cause of the parity error was a broken wire, won't that wire still be broken after the restart, trigging another, and so on?

In his account of the history of the Apollo Guidance Computer, Don Eyles describes the role of a parity bit as follows (p. 80):

... if one of those hair thin wires in our woven core-rope memory happened to break, a parity failure might occur. Each of our fifteen-bit words of memory actually had an additional, sixteenth bit, called the parity bit, which the assembler set to a one or a zero to force the total number of ones among the 16 bits to be odd. When the computer accessed a word of memory it counted the bits that were set to one and if the result was not an odd number it would trigger a restart.

I understand how parity is working here to detect the broken wire; but it's not clear to me what restarting accomplishes. If the cause of the parity error was a broken wire, won't that wire still be broken after the restart, trigging another, and so on?

In his account of the history of the Apollo Guidance Computer, Don Eyles describes the role of a parity bit as follows (p. 80):

... if one of those hair thin wires in our woven core-rope memory happened to break, a parity failure might occur. Each of our fifteen-bit words of memory actually had an additional, sixteenth bit, called the parity bit, which the assembler set to a one or a zero to force the total number of ones among the 16 bits to be odd. When the computer accessed a word of memory it counted the bits that were set to one and if the result was not an odd number it would trigger a restart.

I understand how parity is working here to detect the broken wire; but it's not clear to me what restarting accomplishes. If the cause of the parity error was a broken wire, won't that wire still be broken after the restart, trigging another, and so on?

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orome
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In his account of the history of the Apollo Guidance Computer, Don EylesDon Eyles describes the role of a parity bit as follows (p. 80):

... if one of those hair thin wires in our woven core-rope memory happened to break, a parity failure might occur. Each of our fifteen-bit words of memory actually had an additional, sixteenth bit, called the parity bit, which the assembler set to a one or a zero to force the total number of ones among the 16 bits to be odd. When the computer accessed a word of memory it counted the bits that were set to one and if the result was not an odd number it would trigger a restart.

I understand how parity is working here to detect the broken wire; but it's not clear to me what restarting accomplishes. If the cause of the parity error was a broken wire, won't that wire still be broken after the restart, trigging another, and so on?

In his account of the history of the Apollo Guidance Computer, Don Eyles describes the role of a parity bit as follows (p. 80):

... if one of those hair thin wires in our woven core-rope memory happened to break, a parity failure might occur. Each of our fifteen-bit words of memory actually had an additional, sixteenth bit, called the parity bit, which the assembler set to a one or a zero to force the total number of ones among the 16 bits to be odd. When the computer accessed a word of memory it counted the bits that were set to one and if the result was not an odd number it would trigger a restart.

I understand how parity is working here to detect the broken wire; but it's not clear to me what restarting accomplishes. If the cause of the parity error was a broken wire, won't that wire still be broken after the restart, trigging another, and so on?

In his account of the history of the Apollo Guidance Computer, Don Eyles describes the role of a parity bit as follows (p. 80):

... if one of those hair thin wires in our woven core-rope memory happened to break, a parity failure might occur. Each of our fifteen-bit words of memory actually had an additional, sixteenth bit, called the parity bit, which the assembler set to a one or a zero to force the total number of ones among the 16 bits to be odd. When the computer accessed a word of memory it counted the bits that were set to one and if the result was not an odd number it would trigger a restart.

I understand how parity is working here to detect the broken wire; but it's not clear to me what restarting accomplishes. If the cause of the parity error was a broken wire, won't that wire still be broken after the restart, trigging another, and so on?

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orome
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