MESSAGE
| DATE | 2014-12-06 |
| FROM | Ruben Safir
|
| SUBJECT | Re: [LIU Comp Sci] Parity Bit Algebra
|
From owner-learn-outgoing-at-mrbrklyn.com Sat Dec 6 21:52:27 2014
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Date: Sun, 07 Dec 2014 02:53:03 +0000
From: Ruben Safir
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Subject: Re: [LIU Comp Sci] Parity Bit Algebra
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Really???
there is a theory that you can do all instructions with just a single if
branch and I think this leverages that theory.
Anyway
10 seconds of looking
http://stackoverflow.com/questions/26272447/complete-instruction-set
On 12/07/2014 02:38 AM, Maneesh Kongara wrote:
> I've finished all other questions... I'm breaking my head with the last
> question.
> On Dec 6, 2014 9:36 PM, "Ruben Safir" wrote:
>
>> On 12/06/2014 11:09 PM, Maneesh Kongara wrote:
>>> Preliminary work as in answers to the other questions of the assignment?
>>> On Dec 6, 2014 6:08 PM, "Ruben Safir" wrote:
>> I'm going to crash, how far did you get in the assingment.
>>
>> Call me is 20 minutes. I have one hour to do it :)
>>
>>
>>>> On 12/06/2014 10:52 PM, Maneesh Kongara wrote:
>>>>> Thanks so much for sharing Mr Rubin. Have you completed the assignment?
>>>>> On Dec 6, 2014 5:49 PM, "Ruben Safir" wrote:
>>>> Not even looked at it outside of the library. I'm burning up trying to
>>>> catch up. Do you have some preliminary work?
>>>>
>>>> I did give it throught. Part of the solution must have to do with the
>>>> Comp + 2 binary
>>>>
>>>> I can't even find my notes...
>>>>
>>>>>> This is from theidiscussion of Raid 3 Stallings Text which the slide
>>>>>> come from. It is related to the problem you asked about the parity
>> bit
>>>>>> calculation for the Hamming Code
>>>>>>
>>>>>> Not the methodology for logical calculation, it is straight math
>>>>>>
>>>>>> Note that X is XOR for whatever UFT reason
>>>>>>
>>>>>>
>>>>>> REDUNDANCY In the event of a drive failure, the parity drive is
>> accessed
>>>>>> and data is reconstructed from the remaining devices. Once the failed
>>>>>> drive is replaced, the missing data can be restored on the new drive
>> and
>>>>>> operation resumed.
>>>>>>
>>>>>> Data reconstruction is simple. Consider an array of five drives in
>> which
>>>>>> X0 through X3 contain data and X4 is the parity disk.The parity for
>> the
>>>>>> ith bit is calculated as follows:
>>>>>>
>>>>>> X4(i) = X3(i) { X2(i) { X1(i) { X0(i)
>>>>>>
>>>>>> where { is exclusive-OR function.
>>>>>>
>>>>>> Suppose that drive X1 has failed. If we add X4(i) { X1(i) to both
>> sides
>>>>>> of the preceding equation, we get
>>>>>>
>>>>>> X1(i) = X4(i) { X3(i) { X2(i) { X0(i)
>>>>>>
>>>>>>
>>>>>> file:///home/ruben/william stallings - computer organization and
>>>>>> architecture designing for performance (8th edition).pdf
>>>>>>
>>>>>> Page 202
>>>>>>
>>>>>>
>>>>>>
>>>>>> http://www.nylxs.com/images/raid3_parity_math.png
>>>>>>
>>>>>> Ruben
>>>>>>
>>
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