# Effect of accumulator value

83 views

Jan 19, 2023, 1:31:49 PMJan 19
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Whats the difference between accumulator = "0" and all bits of accumulator equals to "1". How it effects the result and what it changes? Does it changes the instructions that we re executing?
For example :
M[1027]← M[350] - M[65] And AC=0. What s the instructions that we need to use?
M[1027]← M[350] + M[65] And each bit of AC equals to "1". What s the instructions that we need to use?

### MitchAlsup

Jan 19, 2023, 1:48:18 PMJan 19
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On Thursday, January 19, 2023 at 12:31:49 PM UTC-6, omerad...@gmail.com wrote:
> Whats the difference between accumulator = "0" and all bits of accumulator equals to "1".
The former has AC = 000000000000000000
The later has AC = 11111111111111111
Depending on whether we are in 2-s complement, 1's complement, or signed magnitude; the difference4 is 1, or 0, or 0.
<
> How it effects the result and what it changes? Does it changes the instructions that we re executing?
<
We know nothing about the architecture, its numeric properties, and other details:: so it is hard to answer your question.
<
> For example :
> M[1027]← M[350] - M[65] And AC=0. What s the instructions that we need to use?
<
Taking a wild guess:: SUBtract
<
> M[1027]← M[350] + M[65] And each bit of AC equals to "1". What s the instructions that we need to use?
<
<
Although we might need to LD M[350]; ADD M[65]; ST M[350];

### John Levine

Jan 19, 2023, 2:05:40 PMJan 19
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>Whats the difference between accumulator = "0" and all bits of accumulator equals to "1". How it effects the result and what it changes? Does it
>changes the instructions that we re executing?
> For example :
>M[1027]â† M[350] - M[65] And AC=0. What s the instructions that we need to use?
> M[1027]â† M[350] + M[65] And each bit of AC equals to "1". What s the instructions that we need to use?

(Helpful tip: by long tradition, the answers that people post to homework questions are often deliberately wrong.)

--
Regards,
John Levine, jo...@taugh.com, Primary Perpetrator of "The Internet for Dummies",

Jan 19, 2023, 4:04:42 PMJan 19
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19 Ocak 2023 Perşembe tarihinde saat 21:48:18 UTC+3 itibarıyla MitchAlsup şunları yazdı:
thank u so much for your answer. I can explain myself by using pictures of the question but theres no option for pictures, so can we talk in pm or mail??

Jan 19, 2023, 4:06:11 PMJan 19
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19 Ocak 2023 Perşembe tarihinde saat 22:05:40 UTC+3 itibarıyla John Levine şunları yazdı:
Hello Sir, i mailed u and i send u a picture of the architecture, is it possible to answer me on mails. Because there is no option for using pictures for posts. At least i didnt see.

### Peter Lund

Jan 21, 2023, 11:48:28 AMJan 21
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You should use the original German instructions when operating your aircon. The Turkish translations are crap. I am sure you have a family member or a friend of a friend who knows German -- given how many of you seem to somehow have found your way up to Northern Europe. We have been assured they are all valuable and competent Fachkräfte so they should find it easy to help you.

This clearly says: when your aircon is turned off, it becomes a bit colder and when it is turned on, it becomes a bit warmer. Clearly a bad translation!

-Peter

Jan 24, 2023, 1:14:38 PMJan 24
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On Thursday, January 19, 2023 at 11:31:49 AM UTC-7, omerad...@gmail.com wrote:
> Whats the difference between accumulator = "0" and all bits of accumulator
> equals to "1". How it effects the result and what it changes? Does it changes
> the instructions that we re executing?

That's a very strange question to ask.

It might make more sense if the computer you're talking about uses one's complement
representatiion for numbers; then, the two cases you describe would resemble each
other enough that this would be a question.

Otherwise, what you must ask yourself is: what is the function of the accumulator in
a computer that has one? Today, most computers have general register architectures,
and there is no accumulator.

Once you know what the accumulator _is_, this question becomes trivial.

John Savard

Jan 24, 2023, 1:34:31 PMJan 24
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On Thursday, January 19, 2023 at 2:04:42 PM UTC-7, omerad...@gmail.com wrote:

> thank u so much for your answer. I can explain myself by using pictures
> of the question but theres no option for pictures, so can we talk in pm or mail??

I think that you misunderstood the replies you recieved if you reached
the conclusion that the respondents were willing to give you further
assistance. Instead, both of them were advising you that you need to
do your own homework when taking a course.

If the function of the accumulator in a computer is not clear to you, perhaps
you should read the manual for an older computer that has an accumulator,
such as the IBM 704 or the PDP-8. These manuals have been scanned and