h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: Complementary Arithmetic - A1303813
Author: Old Hairy - U241325

With compliments from OH

Good entry, Old Hairy!

Since I already know about 2's complement and 1's complement, I'm not the best person to give an opinion on this one, as it seems pretty obvious to me.

I'd suggest that you don't use the word 'set' to mean 'equal to 1'. That won't be commonly understood by the readers.

maneouvre --> manoeuvre
9'complements --> 9's complements

Thanks Gnomon (glad you're back in action).

Fixed the typos, and tweaked the words near where you suggested 'equals one' for 'set'. Added a footnote there too.

OH

As someone who understands nothing about computers, I don't understand the first paragraph about 16-bit whatsits with a load of numbers...

Hello Cyzaki.

I don't understand the pages with geek code. Over.

I'm not trying to get my personal space into the edited guide though, am I? The entries in the edited guide are supposed to be able to be understood by the average intelligent reader...

But if you don't want my help, that's fine.

Hello Cyzaki.

Sorry, but I do welcome your help. I was trying to be humourous.

If you don't understand those to numbers, is it likely that you would read the entry anyway? I thought that almost as soon as you open a manual (or certain help pages) for just about anything, you bump into those particular numbers.

If you're reading h2g2, doesn't that greatly increase the chances that you do use computers? I had hoped that the first paragraph would give the right message, that is, if this interests you read on, otherwise stop here.

What else might I say?

OH

I don't know - I understood the majority of the rest of the entry, but that first paragraph would definitely put me off reading it. And you don't need to know anything about computers to use the internet - my Nan surfs like a maniac but can't do anything else on her computer other than use the internet. I don't know what you can put instead of that first paragraph, cos I don't understand it so don't know what you're trying to say with it...

When a good geek does turn up to this thread, I know there's a lovely piece of magic on h2g2 whereby you have multiple U-numbers based on exactly this principle.

Problem is, I can't remember exactly how it works. But when someone does explain it, it'd make a wonderful bit of h2g2-trivia for this Entry.

B

Hello Cyzaki.

I have deleted the first paragraph, and added some of its sense to the second. Is that better, or shall I just leave the tidbit out? (My experience is that new computer users are baffled by the magnitude of numbers always being larger in the negative direction, and I really want to mention that the entry explains that.)

OH

I think the bit that's confusing me is "for example, bytes have a range -128 to +127" - 128 what?

I apologise if this is really simple and obvious, but I don't get it

I'd suggest something like "In many programming languages, a byte can be used to store a number between the limits of -128 and +127. The reason that the negative number is one bigger than the positive number is a result of the method used to represent the numbers and makes the arithmetic on these numbers much simpler."

Ah, that I understand . So you use bytes to store the numbers and the numbers tell the computer how to work?

By the way,

unsymettrical --> unsymmetrical

Hello Gnomon and Cyzaki.

Let me welcome the suggestion from Gnomon. I'll adjust that (changing languages to applications perhaps) and put the idea in that way. That should satisfy Cyzaki.

But the comments of Cyzaki I find somewhat difficult. I looked for other guide entries, on reasonably technical subjects that I understand, and came to the entry for me: 'Doppler Effect'. It begins 'The Doppler effect is by definition an apparent shift in the observed frequency of a wave, due to relative motion between the source and the observer.' It does not tell us that a wave is not a method of saying cheerio, that relative motion is not granny moving house, that source is not where rivers start, or that an observer is not a newspaper. Now in my attempted contribution on a type of arithmetic, which includes arithmetic in its title, I have to explain a number at length, which is rather frustrating, and will curtail my future efforts. I cannot, it seems, suppose that there are any readers who have ever encountered integers as they are represented in computers, despite the number of entries related to programming.

Looking at technical entries, I have found that some authors are long gone. Is this why? Has every technical entry to be reduced to the level of the reader for whom a computer is a typewriter with flashing lights? Are technical entries not wanted? Or is it just mathematics that raises the hairs on the back of the neck?

The point I am trying to make is this. A technical article is necessarily about something technical, and will get almost nowhere unless a base knowledge can be assumed. Presumably, if accepted for the edited guide, an entry would be placed somewhere suitable, and that alone ought to qualify the reader in some way. You do not bump into Hookes Law by reading comics.

I tend to start my more technical entries at a very basic level, then increase the technical content as I get into it. I'm sure that many people start reading them, then get lost and give up as they realise they don't have the technical knowledge.

Nevertheless, Cyzaki's criticisms are valid. If it is intended for technically competent readers, it should make it clear at the start what sort of technical expertise the readers require. Since this entry is entitled 'Complementary Arithmetic', one would assume that it is about Arithmetic, not about computers. Since it is about storing numbers on computers, this should be made clear at the start.

Like I said, they should be aimed at an intelligent reader, and such a reader will pick up new concepts quickly. Just a small footnote about what a byte or a bit or whatever it is actually is will suffice, just so people who don't know much about computers but are willing to learn won't get put off reading a good entry by the first paragraph.

Hello both.

I've given up defending mention of binary number ranges, so that part is deleted. I did not understand why the entry might thought to be about storing numbers, but to be safe, in section 'Binary Machines' I changed 'memory' to 'arithmetic hardware'.

OH

There's nothing wrong with mentioning binary number ranges, so long as you explain what you mean by it.

>>I did not understand why the entry might thought to be about storing numbers

Because the arithmetic goes hand-in-hand with the way in which the numbers are stored/represented.