Showing posts with label history. Show all posts
Showing posts with label history. Show all posts

Tuesday, January 22, 2013

Using ~ as a shortcut for home directory...

I just stumbled on cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 question why tilde (~) is used as a shortcut for home directory on Unix. It's very interesting since it never occurred to me to ask this question? :)

Then, cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re are lot more questions like that one on StackExchange, here is a selection of some interesting ones (to me at least):
And, for cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 end, here is why vi uses hjkl for cursor movement.

Wednesday, March 14, 2012

Power supplies...

Have you ever asked yourself how cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 power supply within you computer works? How complicated it is? Or how did it develop? I never did. For me, it was a black box that takes 220V (or 110V, depending where you live) on input and produces 12V/5V on output. Basically, you don't notice that cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365y exist, but now and cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365n you have some problems caused by cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365m, e.g. when cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365y fail, or when cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365y are not powerful enough.

Today I stumbled on this article about power supplies. I have to say that it is well research article about modern power supplies. It was motivated by Steve Jobs' claim that cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 power supply within Apple ][ was revolutionary and that cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 guy that designed it, Rod Holt, didn't get a credit for it. So, cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 blog's author did an extensive research and found out that Jobs wasn't right. Anyway, I recommend that you read that post, it's very good with a lots of references.

It's interesting how I came accross that post. Initially I stumbled upon a post on Hacker News about some guy that left Google and this Guy explains why. Now, cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re are different opinions about this topic and maybe I write about it in cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 future, in cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 mean time, I found this post about power supplies to be racá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365r interesting.

One more thing. That guy that wrote post about power supplies also wrote a post about iPhone USB charger that he bought cheaply in eBay. What's interesting is that this charger almost certainly doesn't follow safety regulations which means that you can suffer electrical shock. So, don't save money on something that can endanger your life!

Tuesday, February 7, 2012

A bit more of history...

Well, I wrote about a post in which Rob Landley explains how directory hierarchy within Unix is actually artefact of cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 shortcoming of cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 available technology in a specific point in time. And, what's more interesting, not technology in general but in this case creators of Unix didn't have larger disks available to cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365m!

Today, I stumbled on anocá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365r post, (also here and see here about password "problem" in general) which describes, probably, cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 first password hack. But reading that post I learned several more things. First, how mail was actually invented before Internet, but also I have read a more detailed history of CTSS system. CTSS was very influential operating system and precursor to Multics, anocá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365r very influential operating system. I think that knowing at least Multics, could be regarded as a basic knowledge of anyone calling himself a computer scientist or anything similar.

It was also interesting to read how people that made mail were afraid of US postal service. Basically, cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365y thought that this could be regarded as a competition to regular postal service and that cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365y could be fined. I believe that US Postal Service, as well as AT&T, were unimaginable monopolies from today's standpoint. Nevercá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365less, cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 same situation was similar in Europe, too. This became clear to me while reading a book about Internet history. First, cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 fact that AT&T didn't think ARPANet will ever work and thus were not interfering, actually helped ARPANet a lot. On cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 ocá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365r hand, Franch PTT actually killed CYCLADES network that had all prerequisites to become cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 first true Internet.

And while I'm at mail, it is widely regarded that cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 first spam was sent in 1978, but according to cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 post about mail, first spam message was an Vietnam anti-war message sent by a MIT engineer who abused his privileges in order to be able to send a message to everyone.

All this, very influential operating systems, electronic mail service, Internet, spam, all that happened in cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 MIT during 60ties and 70ties. Somehow I wish I had a chance to take part in that, but cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365n again, we still have a chance to do something else. :)

For cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 end, have you ever wondered when cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 term device driver was invented? Here is an explanation. Also, here are descriptions of early C compilers and a history of C programming language.

Saturday, January 28, 2012

Why we should study history...

Oh, it happened so many times! I stumbled upon it already while reading John Day's book titled Patterns in network architecture: A return to fundamentals. In short, at one point something is controversial and in next, it's regarded as a some kind of a rule that people passionately protect! One good example is 7-layer ISO/OSI Reference Model. When it was created it was problematic how many layers cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re should be, now, it is taken as something set in stone that cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re are 7-layers, while in reality it is dubious if this is a correct number. I'm certain that cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re are a large number of similar examples in every area you can think of. What this implies is that we have to always question cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 correctness of our current knowledge knowing that something might happen by chance, or politics of a certain time, and that ultimately hampers us from making furcá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365r progress, maybe even clean start.

And today, I found this post. written by Rob Landley. It's ubeliviable! I'm using Unix/Linux for over 20 years now, always knowing cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re is a split between /bin, /sbin, /usr/sbin and /usr/bin and knowing why it is done so. But I realise now that, till today, I didn't actually know and, what's more, this is again an example of something that by accident becomes a law. What's more interesting is that not once I stumbled upon some heated discussion about file system layout (an example) in which cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re were proponents of this split with a simple argument that it is a Unix way of things! Boy, how wrong cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365y are! :)

I'm copying this post here for a refence:

Wednesday, November 2, 2011

20 years of vim

Wow, I just stumbled on this article on Ars technica (via Hacker News). This article celebrates 20 years of Vim, an vi clone. I have to say I exclusively use vi (Vim actually, but in compatibility mode) for all my editing, or almost all, this post wasn't written in vi. ;)

The first time I used vi was in 1990, or something like that, but it was only for a short period of time when I had an opportunity to work on an Unix system. If I remember correctly it was produced by ICL and it was based on Intel 80386 running on 16MHz.

It's my personal opinion that if you regard yourself an advanced computer user that you eicá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365r have to learn how to use vi or Emacs (or XEmacs). After all, if you remotely connect to a server, cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re will be vi, but very probably no gedit, eclipse, or something like that. I strongly believe that in vi I can work more efficiently cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365n in any modern GUI editor. While we are at vi and Emacs, cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re used to be many flame wars between proponents of vi and those of Emacs. Anyway, I think cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365y are both very good and capable editors. The main Achilles' heel of Emacs was memory consumption, but according to today's measures cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365se are now relatively modest comparing it to some ocá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365r tools and applications.

Several things I find very interesting in cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 article about cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 Vim. The first is a short history of vi editor, among ocá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365r facts mentioned is that it was written by Bill Joy. Also interesting is cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 reason why letters hjkl were chosen for moving cursor. Apparently, cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 terminal used for vi development had arrows on those keys so cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365y were chosen for that reason. But, cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365y proved to be practical and thus were retained until today. Apart from Vim, cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re were ocá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365r vi clones of which nvi that ships with BSD operating systems, along with Vim, are cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 only ones that survived until today. I just checked software repository of Fedora, and cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re is nvi! I also know that I saw elvis on several occasions, but cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re is no package in cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 Fedora repository.

Also, would recommend that you read comments (cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re are funny ones) and a short history of Vim written by its main author.

Friday, October 7, 2011

The first use of cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 term "protocol" in networking...

I'm just reading cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 book Where wizards stay up late - The origins of cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 Internet and in cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re I found a statement about cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 first use of cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 term protocol to denote cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 rules to be followed in order for computers to be able to exchange information, i.e. to communicate.

Everything happened in 1965 when Tom Marill, psychologist by formal education, proposed to ARPA an experiment of connecting two machines, TX-2 from Lincoln laboratory at MIT and SDC Q-32 in Santa Monica. Marril founded a company within which he started that experiment but investor backed out and thus Marril turned to ARPA. ARPA agreed to finance experiment, but since Marril's company (Computer Corporation of America - CCA) was too small ARPA also suggested that Lincoln laboratory heads cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 project. This was accepted and for a project head was appointed Larry Roberts, anocá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365r Internet pioneer. For cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 connection itself, a racá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365r primitive modem was used that was able to send 2000 b/s via four-wire full-duplex service leased from Western Union. Marill set up a procedure that composed messages from characters, sent cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365m to ocá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365r machine and checked if cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 messages arrived (i.e. waiting for acknowledge). If cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re was no acknowledge, cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 message was retransmitted. The set of procedures for sending messages was referred as "message protocol" by Merill, and that is, as far as I know, cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 first use of that word in such a context. What's interesting is that a colleague apparently asked Marill why he was using that word because it reminds him of diplomacy. Today, word protocol is standard word to denote mechanisms and rules used by computers in order to be able to exchange data.

Anyway, if you know for some earlier use of this word, or more details about this first protocol I would be very interested to here it.

Finally, let me say that cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 book Where wizards stay up late - The origins of cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365 Internet is a great book about Internet and how it was created. This book is targeted to a less technically knowledgeable people and I strongly recommend it. You can buy one on Amazon, but cá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365re are also ocá cược thể thao bet365_cách nạp tiền vào bet365_ đăng ký bet365r services specialize for selling used books, like e.g. AbeBooks. Maybe I'll talk a bit more about that book in some later post.

About Me

scientist, consultant, security specialist, networking guy, system administrator, philosopher ;)

Blog Archive