The RR-Net Ethernet card is a re-design and logical continuation of the TFE Ethernet card, for which Contiki was originally written. The RR-Net and the TFE are built upon the same Ethernet controller chip: the CS8900a, which has an 8-bit mode and is very well suited for interfacing with 8-bit CPUs and microcontrollers.
I am actually running Contiki together with an RR-Net Ethernet card on my 10 MBit/s broadband connection myself. Of course, it isn't actually possible to saturate the connection with the C64, but at least it is possible to finally use a C64 with the Internet without having to go through a PC, which is quite satisfying:-)
Do you also notice the change in dresscode from back then? Most of the people you see on those photographs wear suits and tie; such clothes are quite hard to find in the typical computer halls of today.
When did this change happen? Was it when computers changed from being a purely military project and moved out into academia?
Also check out the amazing 4k demos by Sanction - especially the unbelievable Omniscent demo from 1997. It is a clone of the popular 3D game Descent (it was popular a few years ago) - in 4 kilobytes! It even has music.
Most of the wall textures are calculated on-the-fly as the demo runs, only the animated stars texture is predrawn.
There are also two other 4k demos on the same site, but I personally prefer Omniscent.
When runing, those 4k demos use a lot more memory than 4k, however. Commonly around 500-600k which is the maximum amount of memory avaliable under 16-bit real-mode MS-DOS (without using EMM386 and other expanders). Usually, the 4k binary is compressed using clever compression techniques and is decompressed when the binary is run. But still, cramming a 3D world with textures and music into 4k is quite an accomplishment!
In a symbolic meeting between academia and the rest of the world, Stockholm's night sky will be adorned by a beam of light. A beam that has its origins in history, is part of our time and endeavours towards the future. A beam reflecting the advancements of technology and enterprise. A curious beam.
From a point 30 meters below the face of the earth, where once Sweden's first nuclear reactor was, a laser beam is produces and is reflected by the tower where pioneers once sent the first TV signals across Sweden. From here, the light is further projected over the city before reaching its goal: the City Hall.
At the time MS (and even AT&T) were accused of taking code the BSD licence had one more clause then it has now. Basically a credit clause, you had to acknolage BSD in your documentation (and maybe on screen).
The BSD license still states that you have to acknowledge the copyright holders in the documentation. And Microsoft does that, actually. Look at the copyright section of the Windows XP release notes; there are several acknowledgments to people who have released their source code under the BSD license. It gives credit to Berkeley and other univesities that have large portions of code released under the BSD license, and also to people like Luigi Rizzo how have written a lot of BSD licenced code for the FreeBSD project.
The reason why sites are brought down because of the slashdot effect is probably a combination of two things: (1) large pictures on the web page (like in this case) and (2) lots of server side scripting. In the former case the server bandwidth is the bottleneck, whereas in the latter case the server runs out of CPU cycles and RAM.
I have been slashdotted twice myself (Streaming RealAudio From a Commodore 64 and VNC Server for Toasters and Light-Switches). In both cases the web server running on the Commodore 64 was really slow because of the load, whereas the "regular" web server hosting the description pages behaved differently in the two cases. The first time there were a number of pictures on the linked page, and the web server was sluggish because of the load. The other time the web page only consisted of a single HTML text page with a single picture and the load on the web server was hardly noticeable.
The web server on the first occation was a dual CPU PC with 2 GB RAM and for the second occation the server was a single CPU PC with 256 MB RAM. The first web server also hosts some hundred domains, whereas the second only hosts one. The Commodore 64 has 64kB RAM and runs at 1 MHz, but only hosted one domain.
To sum up: a web server running on a Commodore 64 is a little too slow to be able to deliver pages in full speed during a slashdotting, whereas a PC can handle it, given that the web page consists mostly of text and doesn't have too many heavy scripts.
Computer games indirectly spurred a different kind of computer art as well. In the early 80s, when the computer games were starting to become a large industry, some computer interested youngsters started to remove the copy protection (if any) from the games and to spread those cracked games to friends.
Often the crackers changed a few words on the title screen of the game, claiming the credit for having cracked the copy protection. Some guys even linked a special introductory screen with the name of the cracker before the game started.
Over the years, those introductions became more and more advanced with music, graphical logotypes, and scrolling text. The first intros used the title music from the game or from some other game, but soon the crackers started making their own music while at the same time improving their programming skills and graphical capabilities.
After a while, the cracker intros were actually more technically and artistically advanced than the games themselves!
In parallell with the improvements to the intros, the intros forked off into the demo concept. The demos were more technically advanced than the cracker intros, and most commonly all graphics and music was done by the demo creators themselves and not taken from some game. The demos pushed the limits of the computers on which they ran and in turn inspired the games creators.
More information about the intros found on the classical Commodore 64 computer can be found at intros.c64.org and a very good collection of Commodore 64 demos can be found at www.c64.ch. If you don't have access to a Commodore 64 or a Commodore 64 emulator, there is a good DivX encoded video showing one of the best C64 demos around: Deus Ex Machina by Crest.
In a sense, the gaming industry made it possible for the creation of the cracker intros, which in turn led to the demo artform - an artform like no other.
11 hours after the Slashdot appearence, the C64 is still running. It is a bit slow because of the large amount of traffic, but it is still possible to reach it. In fact - the C64 seems to handle the load better than my web hosting provider for dunkels.com who apparently had to start denying access because of the overload.
About half an hour ago, I managed to get the access statistics. It shows a total of 63000 accesses, which is twice as much as 5 hours earlier. 18000 accesses (28%) was for the/index.html page.
Ooops, thanks for pointing that out! Unfortunately we cannot change the web pages without rebooting the C64 which would reset the access statistics back to zero.
It has now been four and a half hours since this appeared on the front page, and our C64 server is still up and running.
I was just able to reach the access statistics page. There has been a total of 32000 accesses (of which 8000 came before the Slashdot attack). 25% of the accesses have been for the/index.html page and only 1% have been for the RealPlayer description file/c64.ram.
24000 hits in 4.5 hours, thats nearly 1.5 hits per second.
As one of the guys who made this, I must say that I am amazed to see how well our C64 server is handling the Slashdot-effect. With a little more than 50 comments, I still can load parts of the first page.
The web server that runs on port 80-84 actually implements a simple form of overload protection and during testing, we managed to serve 8000 pages over a period of 30 minutes. That makes 4 pages per second! Note that it is only the first page that is overload protected, so the other pages will still load very slow (if they will have a chance to load at all!).
The real-time streaming audio server is running on the same machine as the web server so nobody will probably have a chance to hear the audio stream.
Furthermore, the headline is wrong - we are not streaming RealAudio. We are streaming audio using the open RTSP/RTP formats that RealPlayer and other players can handle. The RealAudio file format is secret so we would probably have been sued if we had been streaming that.
Finally, here is Google's cache of our newsgroup announcement.
If I don't want to license, and I don't want to give up, then I have to innovate!
So, what you are saying is that patents are good because they force people to make "innovations" to get around other peoples patents. That sounds very counter-productive to me. Instead of building on other peoples inventions and making progress, inovators have to focus their energy on getting around patents.
Suppose that someone had patented the wheel. Then people would have to come up with weird "inventions" like "a square wheel" to be able to build carts or anything else that used the wheel (or something wheel-like). If the wheel hadn't been patented, people could just have used the wheel to build new innovations.
Towers of Hanoi & Mandelbrot for vim
on
SedSokoban
·
· Score: 2
Linus Åkerlund's Towers of Hanoi implementation for vim. can be found here. He has also written a cool Mandelbrot set generator in vim that can be found on the same page.
All versions and variants of the BSD license require that credit is given to the copyright holder. The only difference with the "new" version is that credit no longer has to be given in advertising material that mentions use or features of the code.
Credit still has to be given in all documentation provided with the software, as well as within the source code. "Give credit" in this case really means that the whole software license, including a disclaimer, has to be reproduced with every copy.
If you like C64 remixes, also check the Remix64 community site out: http://remix64.phatsites.de/. The charts section contains voting charts for the remixes at Remix.Kwed.Org and is a good place to start in order to find out which remixes are worth downloading.
Funny that you mention this. Modularization and simplicity is actually the main idea behind X as well. The X server only knows how to draw certain drawing primitives such as lines, boxes, circles, etc., and leaves the rest to other modules. Menus, buttons, scrollbars, etc., are handled by the widget toolkit; window borders and the user interface for moving and resizing them are left to the window manager.
Even if the main X distribution may be bloated and even if Berlin is a much better framework for building graphical environments, the ideas beind X are still simplicity and modularity.
The only reason why DOS can be considered real-time is that it completely stays out of the way. DOS has the nature of a code library more than an operating system in that DOS only provides services in the form of extra system calls. It does not provide multi-threading, inter-process communication, timers, interrupt handling with controlled latency, or other things that normally are considered RTOS (Real-Time Operating System) services. DOS is not an RTOS, it is just a boot-loader for your own real-time programs.
You could just as well have used a simple boot loader together with a function library such as libc to get the same functionality.
This is not intended to bash against DOS; DOS might be the perfect choice for many applications. I just don't want people to confuse DOS with actual real-time operating systems.
Here is some technical information about this achievement.
The "brain" in the Lego Mindstorms product family is the RCX;
essentially a small microcontroller with an LCD display built into a
Lego brick. It has connectors for sensors and motors as well as an infra-red
port. The microcontroller is an Hitachi H8/3292 from the H8S/300
family. It has 32k RAM and a 16k ROM which hosts Lego firmware code.
The microcontroller can be entirely reprogrammed, which turns the RCX
into a small but powerful embedded computer. With 32k RAM, this is
enough to run the open-source legOS operating system - an
operating system written for the RCX Lego bricks. Olaf Christ has
taken the uIP TCP/IP stack (which was originally written for this
project) and incorporated it into the legOS system.
IP packets are sent to and from the RCX over the IR link. The LNP
protocol is used as a link layer protocol to deal with collision
detection and link layer checksums.
The main problem with the TCP/IP-enabled Lego bricks is that the IR
port on the RCX only is capable of running 4800 bit/sec. Since that's
even slower than most really old modems, a Lego web server is easily
slashdotted by one user alone...
While the uIP TCP/IP stack was originally written for this project it has
since taken a life of its own and has not only been used to power good
old C64s, but is also used in several embedded systems such as
card-readers and other point-of-sale-type applications.
I have personally been running Olaf Christ's TCP/IP code on an RCX and
can confirm that it works. In fact, I have one sitting here and
serving web pages right now. Sorry, I won't give out the IP address
due to the slashdot effect...
How long before the Linux kernel is forked by someone that actually does version management with CVS? Linus' Linux versions could be patched back into the CVS/Linux code, while developers could focus on the actual problems at hand instead of messing with patches, submissions and the general frustration of getting you patchest dropped by Linus.
I wish M$ was required to print an acknowledgement on every Windows box that mentions that their TCP stack is derived from BSD instead of putting on like they're the only company that's every produced useful software.
This list not only contains acknowledgements to Berkeley, but also to a number of other companies, universities, and individuals who apparently published their code under a BSD-style license.
OK, maybe it's just me, but doesn't this open up a big DoS possibility?
A trojan (say on a Windows machine) could sit quietly listening for such requests, and NACK every one that comes along..
Or is there a mechanism to prevent this?
This mechanism is used only on the local network. No autoconfiguration packets ever leave the network, and no routers will forward such packets onto the network.
If the trojan machine is sitting on the local network, it can do all kinds of bad things anyway - such as flooding the network with random data. In general, it is impossible to guard against "bad" hosts on the local network.
So, whats missing for home use of ethernet and TCP/IP in all the devices? A standard, flexible resource discovery system (I know of a few in the works, none finished), and every home to have a NATing DHCPing DSL / cable modem router, so any boxes the user plugs in will be given an IP in the correct address space.
IPv6 addresses both the NAT-problem and the DHCP-problem by a mechanism known as stateless autoconfiguration of IP(v6) addresses. Basically, an IPv6 node picks an address at random and broadcasts a message to see if anybody else has claimed that address. If so, it choses another address at random and tries to claim that one instead. Since IPv6 has a very large address space, there won't be any need for NAT.
There are similar stateless autoconfiguration stuff for IPv4, such as the Universal Plug-and-Play system that was being used by both Microsoft and Apple and is not being standardized by the zeroconf IETF working group.
The problem with IPv4 is of course that NAT or proxying still is needed for global connectivity.
Slashdot Mirror
ah, kicked that submit button too fast...
:-)
The RR-Net Ethernet card is a re-design and logical continuation of the TFE Ethernet card, for which Contiki was originally written. The RR-Net and the TFE are built upon the same Ethernet controller chip: the CS8900a, which has an 8-bit mode and is very well suited for interfacing with 8-bit CPUs and microcontrollers.
I am actually running Contiki together with an RR-Net Ethernet card on my 10 MBit/s broadband connection myself. Of course, it isn't actually possible to saturate the connection with the C64, but at least it is possible to finally use a C64 with the Internet without having to go through a PC, which is quite satisfying
That was also done by Adam Dunkels, the guy behind Contiki and the RR-Net Ethernet card.
Do you also notice the change in dresscode from back then? Most of the people you see on those photographs wear suits and tie; such clothes are quite hard to find in the typical computer halls of today.
When did this change happen? Was it when computers changed from being a purely military project and moved out into academia?
Also check out the amazing 4k demos by Sanction - especially the unbelievable Omniscent demo from 1997. It is a clone of the popular 3D game Descent (it was popular a few years ago) - in 4 kilobytes! It even has music. Most of the wall textures are calculated on-the-fly as the demo runs, only the animated stars texture is predrawn.
There are also two other 4k demos on the same site, but I personally prefer Omniscent.
When runing, those 4k demos use a lot more memory than 4k, however. Commonly around 500-600k which is the maximum amount of memory avaliable under 16-bit real-mode MS-DOS (without using EMM386 and other expanders). Usually, the 4k binary is compressed using clever compression techniques and is decompressed when the binary is run. But still, cramming a 3D world with textures and music into 4k is quite an accomplishment!
Ooops, sorry the headline should say "Stockholm by light". I really missed that pun :-)
"Stockholm by night"
In a symbolic meeting between academia and the rest of the world, Stockholm's night sky will be adorned by a beam of light. A beam that has its origins in history, is part of our time and endeavours towards the future. A beam reflecting the advancements of technology and enterprise. A curious beam.
From a point 30 meters below the face of the earth, where once Sweden's first nuclear reactor was, a laser beam is produces and is reflected by the tower where pioneers once sent the first TV signals across Sweden. From here, the light is further projected over the city before reaching its goal: the City Hall.
Well, it wasn't strictly a Unix system - it was an IRIX system.
The reason why sites are brought down because of the slashdot effect is probably a combination of two things: (1) large pictures on the web page (like in this case) and (2) lots of server side scripting. In the former case the server bandwidth is the bottleneck, whereas in the latter case the server runs out of CPU cycles and RAM.
I have been slashdotted twice myself (Streaming RealAudio From a Commodore 64 and VNC Server for Toasters and Light-Switches). In both cases the web server running on the Commodore 64 was really slow because of the load, whereas the "regular" web server hosting the description pages behaved differently in the two cases. The first time there were a number of pictures on the linked page, and the web server was sluggish because of the load. The other time the web page only consisted of a single HTML text page with a single picture and the load on the web server was hardly noticeable.
The web server on the first occation was a dual CPU PC with 2 GB RAM and for the second occation the server was a single CPU PC with 256 MB RAM. The first web server also hosts some hundred domains, whereas the second only hosts one. The Commodore 64 has 64kB RAM and runs at 1 MHz, but only hosted one domain.
To sum up: a web server running on a Commodore 64 is a little too slow to be able to deliver pages in full speed during a slashdotting, whereas a PC can handle it, given that the web page consists mostly of text and doesn't have too many heavy scripts.
Computer games indirectly spurred a different kind of computer art as well. In the early 80s, when the computer games were starting to become a large industry, some computer interested youngsters started to remove the copy protection (if any) from the games and to spread those cracked games to friends.
Often the crackers changed a few words on the title screen of the game, claiming the credit for having cracked the copy protection. Some guys even linked a special introductory screen with the name of the cracker before the game started.
Over the years, those introductions became more and more advanced with music, graphical logotypes, and scrolling text. The first intros used the title music from the game or from some other game, but soon the crackers started making their own music while at the same time improving their programming skills and graphical capabilities.
After a while, the cracker intros were actually more technically and artistically advanced than the games themselves!
In parallell with the improvements to the intros, the intros forked off into the demo concept. The demos were more technically advanced than the cracker intros, and most commonly all graphics and music was done by the demo creators themselves and not taken from some game. The demos pushed the limits of the computers on which they ran and in turn inspired the games creators.
More information about the intros found on the classical Commodore 64 computer can be found at intros.c64.org and a very good collection of Commodore 64 demos can be found at www.c64.ch. If you don't have access to a Commodore 64 or a Commodore 64 emulator, there is a good DivX encoded video showing one of the best C64 demos around: Deus Ex Machina by Crest.
In a sense, the gaming industry made it possible for the creation of the cracker intros, which in turn led to the demo artform - an artform like no other.
11 hours after the Slashdot appearence, the C64 is still running. It is a bit slow because of the large amount of traffic, but it is still possible to reach it. In fact - the C64 seems to handle the load better than my web hosting provider for dunkels.com who apparently had to start denying access because of the overload.
/index.html page.
About half an hour ago, I managed to get the access statistics. It shows a total of 63000 accesses, which is twice as much as 5 hours earlier. 18000 accesses (28%) was for the
Ooops, thanks for pointing that out! Unfortunately we cannot change the web pages without rebooting the C64 which would reset the access statistics back to zero.
It has now been four and a half hours since this appeared on the front page, and our C64 server is still up and running.
/index.html page and only 1% have been for the RealPlayer description file /c64.ram.
I was just able to reach the access statistics page. There has been a total of 32000 accesses (of which 8000 came before the Slashdot attack). 25% of the accesses have been for the
24000 hits in 4.5 hours, thats nearly 1.5 hits per second.
As one of the guys who made this, I must say that I am amazed to see how well our C64 server is handling the Slashdot-effect. With a little more than 50 comments, I still can load parts of the first page.
The web server that runs on port 80-84 actually implements a simple form of overload protection and during testing, we managed to serve 8000 pages over a period of 30 minutes. That makes 4 pages per second! Note that it is only the first page that is overload protected, so the other pages will still load very slow (if they will have a chance to load at all!).
The real-time streaming audio server is running on the same machine as the web server so nobody will probably have a chance to hear the audio stream.
Furthermore, the headline is wrong - we are not streaming RealAudio. We are streaming audio using the open RTSP/RTP formats that RealPlayer and other players can handle. The RealAudio file format is secret so we would probably have been sued if we had been streaming that.
Finally, here is Google's cache of our newsgroup announcement.
Suppose that someone had patented the wheel. Then people would have to come up with weird "inventions" like "a square wheel" to be able to build carts or anything else that used the wheel (or something wheel-like). If the wheel hadn't been patented, people could just have used the wheel to build new innovations.
Linus Åkerlund's Towers of Hanoi implementation for vim. can be found here. He has also written a cool Mandelbrot set generator in vim that can be found on the same page.
All versions and variants of the BSD license require that credit is given to the copyright holder. The only difference with the "new" version is that credit no longer has to be given in advertising material that mentions use or features of the code.
Credit still has to be given in all documentation provided with the software, as well as within the source code. "Give credit" in this case really means that the whole software license, including a disclaimer, has to be reproduced with every copy.
If you like C64 remixes, also check the Remix64 community site out: http://remix64.phatsites.de/. The charts section contains voting charts for the remixes at Remix.Kwed.Org and is a good place to start in order to find out which remixes are worth downloading.
Funny that you mention this. Modularization and simplicity is actually the main idea behind X as well. The X server only knows how to draw certain drawing primitives such as lines, boxes, circles, etc., and leaves the rest to other modules. Menus, buttons, scrollbars, etc., are handled by the widget toolkit; window borders and the user interface for moving and resizing them are left to the window manager.
Even if the main X distribution may be bloated and even if Berlin is a much better framework for building graphical environments, the ideas beind X are still simplicity and modularity.
The only reason why DOS can be considered real-time is that it completely stays out of the way. DOS has the nature of a code library more than an operating system in that DOS only provides services in the form of extra system calls. It does not provide multi-threading, inter-process communication, timers, interrupt handling with controlled latency, or other things that normally are considered RTOS (Real-Time Operating System) services. DOS is not an RTOS, it is just a boot-loader for your own real-time programs.
You could just as well have used a simple boot loader together with a function library such as libc to get the same functionality.
This is not intended to bash against DOS; DOS might be the perfect choice for many applications. I just don't want people to confuse DOS with actual real-time operating systems.
Here is some technical information about this achievement.
The "brain" in the Lego Mindstorms product family is the RCX; essentially a small microcontroller with an LCD display built into a Lego brick. It has connectors for sensors and motors as well as an infra-red port. The microcontroller is an Hitachi H8/3292 from the H8S/300 family. It has 32k RAM and a 16k ROM which hosts Lego firmware code.
The microcontroller can be entirely reprogrammed, which turns the RCX into a small but powerful embedded computer. With 32k RAM, this is enough to run the open-source legOS operating system - an operating system written for the RCX Lego bricks. Olaf Christ has taken the uIP TCP/IP stack (which was originally written for this project) and incorporated it into the legOS system.
IP packets are sent to and from the RCX over the IR link. The LNP protocol is used as a link layer protocol to deal with collision detection and link layer checksums.
The main problem with the TCP/IP-enabled Lego bricks is that the IR port on the RCX only is capable of running 4800 bit/sec. Since that's even slower than most really old modems, a Lego web server is easily slashdotted by one user alone...
While the uIP TCP/IP stack was originally written for this project it has since taken a life of its own and has not only been used to power good old C64s, but is also used in several embedded systems such as card-readers and other point-of-sale-type applications.
I have personally been running Olaf Christ's TCP/IP code on an RCX and can confirm that it works. In fact, I have one sitting here and serving web pages right now. Sorry, I won't give out the IP address due to the slashdot effect...
How long before the Linux kernel is forked by someone that actually does version management with CVS? Linus' Linux versions could be patched back into the CVS/Linux code, while developers could focus on the actual problems at hand instead of messing with patches, submissions and the general frustration of getting you patchest dropped by Linus.
This list not only contains acknowledgements to Berkeley, but also to a number of other companies, universities, and individuals who apparently published their code under a BSD-style license.
If the trojan machine is sitting on the local network, it can do all kinds of bad things anyway - such as flooding the network with random data. In general, it is impossible to guard against "bad" hosts on the local network.
There are similar stateless autoconfiguration stuff for IPv4, such as the Universal Plug-and-Play system that was being used by both Microsoft and Apple and is not being standardized by the zeroconf IETF working group.
The problem with IPv4 is of course that NAT or proxying still is needed for global connectivity.