Saturday, May 21, 2005

Chip Chapin: Chip's CD Media Resource Center

What's Here

This document contains basic practical information for users of CD media, especially CD-recordable, or CD-R. Serious users of CD-R will naturally have several important questions about the medium, including:

* What kind should I buy?
* How long will they last?
* Does recording speed matter?

This document provides answers (with varying degrees of authority) for each of these questions.

Besides the basic information, I felt it necessary or worthwhile to include some detailed background information about the structure and organization of the discs. How many bits are stored on CD? Lots more than most people realize. This was the type of information that I thought would be easy to find on the internet in the year 2000. But it wasn't. I had to check and compare a number of different sources in order to pull it all together.

Disclaimer: I am not now, nor ever have been, an expert on CD media. These were my own questions. In researching the answers for myself I wrote this document. -- Chip


Why This Document?

In December 2000 I completed a project transferring about 5 hours of audio interviews with elder family members to audio CDs using CD-Rs. My intent was that the discs would last for at least one family generation (25 years or more).

But the very day that I sent out copies to various family members I began to worry about how long these CD-Rs would last. I vaguely recalled hearing something about the instability of the dye layer. I didn't know what the "dye layer" was -- perhaps it would fade or run? Kodak offers CD-Rs that are supposed to last 12 times longer (than what?). Should I redo all the copies using these special archival (i.e. "more expensive") media?

I also began to worry that I had erred in recording my discs at high speed (8x). One of my friends had heard that CD-R creation is somehow better when done at low speed (1x or 2x). I know that low speed duplication is superior for analog tape, but it had never occurred to me that it could make any difference to a digital medium.

Anyway, having no real idea of how long CD-Rs would last, or of the real differences between "gold" and "silver" discs, etc., I decided to research the questions. My results are summarized here, along with many links that I found helpful along the way.

Andy McFadden's CD-Recordable FAQ

What does this FAQ cover (and not cover)?

This document attempts to answer Frequently Asked Questions about Compact Disc Recordable technology and related fields. It was originally developed as a Usenet newsgroup FAQ, and is updated and posted about once a month. The main foci are explaining CD-R technology, describing hardware and software solutions for creating audio CDs and CD-ROMs, and helping people find solutions to common problems.

The FAQ is heavily biased toward PCs and computer-based recorders, because that's what I'm most familiar with, but I have made an effort to include useful information for owners of other equipment. I don't anticipate the section on stand-alone audio CD recorders expanding greatly, because they're far simpler to operate than computer-based recorders, and most of the "must know" information about them is more appropriate in an FAQ on stereo systems or studio recording. I do try to address deficiencies in Macintosh coverage.

I don't usually address questions that can be phrased, "how do I make my software do this?" The answers to those should be in the manual that came with your software. In general, this is a collection of answers to specific questions, not a "how to" guide. I have tried to make the answers easy to understand by an inexperienced user, but if you know absolutely nothing about recording CDs then some sections may be confusing.

This is not a newsletter. Actively maintained web sites are a much better source of breaking news than this document, which is updated at most once a month. I also don't try to track moving targets, like CD recorder firmware versions or software versions unless a specific release is especially interesting. Ditto for which recorders work with which packet-writing solutions, or which recorders can overburn.

This FAQ does not, and will not, cover DVD, DVD-ROM, DVD-R, DVD-RAM, DVD-RW, DVD+RW, or any of the other formats in the ever-expanding DVD morass. There are other resources on the web for DVD topics.

You will not find a lot of detail about "backing up" copy-protected software, or where to find unlock codes or "warez". There are many web sites that explain these matters at length.

Wednesday, May 18, 2005

Memoriakartyak digitalis fenykepezogepekhez

Az index cikke cimszavakban:
Jelenleg forgalomban lévő legfontosabb kártyatípusok
De vajon mennyire elterjedtek az egyes típusok?
Árak
Milyet vegyünk?
Milyen sebességűt?
Mekkora kapacitásút vásároljunk?
A szokásos kérdés: márkásat vagy nem márkásat vegyek?
Speciális kártyák

A cikkben tobb helyen emlegetett RAW formatum:
A felsőbb kategóriás digitális fényképezőgépek többsége lehetővé teszi az érzékelő (CCD vagy CMOS) által rögzített képeket feldolgozás nélkül, nyers (RAW) formátumban történő elmentését. A módszer előnye, hogy a kép sokkal több információt tartalmaz, mint amit a JPEG formátumban le lehet tárolni, így a kép expozíciójának, fehéregyensúlyának és egyéb jellemzőjének állítása, finomhangolása utólag is "büntetés nélkül" elvégezhető. A nyers formátum használatának a hátránya, hogy a képek utólagos feldolgozás nélkül használhatatlanok. A nyers formátumot digitális negatívként is emlegetik.

Monday, May 16, 2005

kepregeny.net

Igy jellemzik magukat:

-Egy oldal mindazoknak akik szeretik a képregényeket, kortól és nemtől függetlenül...
-Egy oldal, ahol lelkes (amatőr) fordítók és beírók egyre népesebb csapata igyekszik igényes tálalásban, magyar nyelven közkinccsé tenni a világ válogatott képregényirodalmát...
-Egy oldal, ahol rábukkanhatunk gyermekkorunk kedvenc képregényeire...
-Egy oldal, ahol hasonló erdeklődésű emberekkel oszthatjuk meg véleményünket, ötleteinket... akár a gondjainkat is...
-Egy oldal, ahol mindig friss információkat kaphatunk erről a hazánkban kissé háttérbe szorult művészeti ágról és az ahhoz kapcsolódó eseményekről, rendezvényekről...

Ebbol nekem a 3. pont tetszett legjobban. Tobbek kozott ilyeneket talaltam:
Asterix
Dr Bubo
Fix es Foxi
Kockas
Lucky Luke
Mezga Csalad
Mozaik
Pif
Pifu
Rejto Sorozat
Tarzan

Friday, May 13, 2005

[MS Word] a PageSetup.PaperSize megvaltoztatasa atallitja a PageSetup.Orientation-t is

Ha kodbol szeretne az ember elfektetni a papirjat es beallitani a papirmeretet is, akkor vigyazni kell a sorrendre, mert a PageSetup.PaperSize megvaltoztatasa automatikusan atallitja a PageSetup.Orientation-t wdOrientPortrait-ra (0), tehat ha valaki azt irja, hogy:

doc.Sections(1).PageSetup.Orientation = wdOrientLandscape
doc.Sections(1).PageSetup.PaperSize = wdPaperA4

akkor ugyanugy allo papirja lesz, mintha el se fektette volna. Ezert jobb a forditott sorrend:

doc.Sections(1).PageSetup.PaperSize = wdPaperA4
doc.Sections(1).PageSetup.Orientation = wdOrientLandscape

Nem hiszem, hogy ez lenne a normalis mukodes. Inkabb valami hibanak tunik. Igy mukodik a 7-es Word-ben es a 11-esben is.

Ezzel a macro-val ki lehet probalni:

Sub ChangeOrientation()

Dim doc

Set doc = Documents.Add()
Call MsgBox(doc.Sections(1).PageSetup.Orientation)
doc.Sections(1).PageSetup.Orientation = wdOrientLandscape
Call MsgBox(doc.Sections(1).PageSetup.Orientation)
doc.Sections(1).PageSetup.PaperSize = wdPaperA4
Call MsgBox(doc.Sections(1).PageSetup.Orientation)

End Sub

Wednesday, May 11, 2005

Method Studios

Ok keszitettek az a Powerade reklamot, amiben James dobalja az egeszpalyasokat. Csinaltak egy halom mas dolgot is, amibol sokminden megtekintheto az oldalukon.
Peldaul:
A kosarlabda az ember legjobb baratja.
A kosarlabda nem is olyan jo barat.

Sunday, May 08, 2005

Scott Mitchell: Why I Don't Use DataSets in My ASP.NET Applications

...during my talk I mentioned how I, personally, rarely, if ever, use DataSets in my ASP.NET applications, sticking with the good ol' DataReader instead. Since then I have received a number of emails from attendees asking me why I don't use DataSets. Rather than responding to each questioner individually, I decided to write this article explaining my rationale.

A lenyeg:
Simply put, the DataSet's increased feature set makes it a less performant choice for reading data than the DataReader.

2 forrasra hivatkozik:
- According to A Speed Freak's Guide to Retrieving Data in ADO.NET, the DataReader is roughly thirty times more performant than the DataSet.
- Additional statistics can be found at Performance Comparison: Data Access Techniques, which compares the DataSet and DataReader against a number of common data access scenarios. The end result is that the DataReader is more performant than the DataSet, although this particular article's results do not show as large a performance difference between these two data objects as the Speed Freak article does.

Felteszi a kerdest: When is a DataSet Useful?
Es 2 ilyen lehetoseget hoz fel:
-In a desktop, WinForms application.
-For sending/receiving remote database information or for allowing communication between disparate platforms.
De hozzateszi:
Now, how often are you doing either of these things in your day-to-day ASP.NET development? Hardly ever, I'd wager, which is why you probably shouldn't be using DataSets! While the ASP.NET data Web controls are rather indifferent on what data object you use, you are suffering from a performance loss by choosing to use a DataSet.

A konkluzioja:
In this article we examined the fundamentals of the two data access objects provided by ADO.NET: the DataReader and the DataSet. Both objects have their time and place in .NET applications but, in my opinion, DataSets are rarely, if ever, useful in ASP.NET Web applications. There are exceptions, granted, but for the majority of Web applications, DataReaders should be used exclusively.

Sunday, May 01, 2005

153

"Simon Peter went up, and drew the net to land full of great fishes, an hundred and fifty and three: and for all there were so many, yet was not the net broken." (John 21:11)

153 is a neat number. Here are four reasons:

1. 153 = 1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17

2. 153 = 1! + 2! + 3! + 4! + 5! (i.e., 1 + (1 x 2) + (1 x 2 x 3) + (1 x 2 x 3 x 4) + (1 x 2 x 3 x 4 x 5))

3. 153 = 13 + 53 + 33

4. 153 lies dormant in every third number. Take any multiple of three, sum the cubes of its digits, take the result, sum the cubes of its digits, take the results, etc. Believe me. You eventually get 153. Take 12, for example.
13 + 23 = 9.
93 = 729.
73 + 23 + 93 = 1080.
13 + 03 + 83 + 03 = 513.
Finally, 53 + 13 + 33 = 153.

forras

Friendly Numbers

Pythagoras considered 220 and 284 to be friendly (or amicable). He even wrote: "[A friend] is the other I, such as are 220 and 284". Aristotle also used the notion of friendly numbers to characterize friendship (in his work "Ethics"). So what makes the numbers 220 and 284 so special? Their property is that each is equal to the sum of the other's proper divisors. The proper divisors of 220 are 1, 2, 4, 5, 10, 11, 20, 22, 44, 55, and 110, and they sum up to 284; the proper divisors of 284 are 1, 2, 4, 71, and 142, and they sum up to 220.

Itt olvashato Ibn Qurra Ibrahim friendly numbers kereso algoritumusa.

CuriousMath.com :: Math is an attitude

Want to learn how to quickly square a number that ends in 5? Or how to tell if a number is divisible by 3? Or maybe you'd like to know why the number 153 in the Bible is such an interesting number? That's the kind of fun and fascinating math tricks and trivia you'll find here at CuriousMath.com.