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• Saying Goodbye To Old Machines

  1er décembre 2014, par Multimedia Mike — General, powerpc, via

  I recently sent a few old machines off for recycling. Both had relevance to the early days of the FATE testing effort. As is my custom, I photographed them (poorly, of course).

  First, there’s the PowerPC-based Mac Mini I procured thanks to a Craigslist ad in late 2006. I had plans to develop automated FFmpeg building and testing and was already looking ahead toward testing multiple CPU architectures. Again, this was 2006 and PowerPC wasn’t completely on the outs yet– although Apple’s MacTel transition was in full swing, the entire new generation of video game consoles was based on PowerPC.

  
  

  

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  I remember trying to find a Mac Mini PPC on Craigslist. Many were to be found, but all asked more than the price of even a new Mac Mini Intel, always because the seller was leaving all of last year’s applications and perhaps including a monitor, neither of which I needed. Fortunately, I found this bare Mac Mini. Also fortunate was the fact that it was far easier to install Linux on it than the first PowerPC machine I owned.

  After FATE operation transitioned away from me, I still kept the machine in service as an edge server and automated backup machine. That is, until the hard drive failed on reboot one day. Thus, when it was finally time to recycle the computer, I felt it necessary to disassemble the machine and remove the hard drive for possible salvage and then for destruction.
  

  If you’ve ever attempted to upgrade or otherwise service this style of Mac Mini, you will no doubt recognize the pictured paint scraper tool as standard kit. I have had that tool since I first endeavored to upgrade the RAM to 1 GB from the standard 1/2 GB. Performing such activities on a Mac Mini is tedious, but only if you care about putting it back together afterwards.

  The next machine is a bit older. I put it together nearly a decade ago, early in 2005. This machine’s original duty was “download agent”– this would be more specifically called a BitTorrent machine in modern tech parlance. Back then, I placed it on someone else’s woefully underutilized home broadband connection (with their permission, of course) when I was too cheap to upgrade from dialup.

  
  

  

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  This is a small form factor system from VIA that was clearly designed with home theater PC (HTPC) use cases in mind. It has a VIA C3 x86-compatible CPU (according to my notes, Centaur VIA Samuel 2 stepping 03, flags : fpu de tsc msr cx8 mtrr pge mmx 3dnow) and 128 MB of RAM (initially ; I upgraded it to 512 MB some years later, just for the sake of doing it). And then there was the 120 GB PATA HD for all that downloaded goodness.

  
  

  

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  I have specific memories of a time when my main computer at home wasn’t working correctly for one reason or another. Instead, I logged into this machine remotely via SSH to make several optimizations and fixes on FFmpeg’s VP3/Theora video decoder, all from the terminal, without being able to see the decoded images with my own eyes (which is why I insist that even blind people could work on video codecs).

  By the time I got my own broadband, I had become inspired to attempt the automated build and test system for FFmpeg. This was the machine I used for prototyping early brainstorms of FATE. By the time I put a basic build/test system into place in early 2008, I had much faster computers that could build and test the project– obvious limitation of this machine is that it could take at least 1/2 hour to build the entire codebase, and that was the project from 8 years ago.

  So the machine got stuffed in a closet somewhere along the line. The next time I pulled it out was in 2010 when I wanted to toy with Dreamcast programming once more (the machine appears in one of the photos in this post). This was the only machine I still owned which still had an RS-232 serial port (I didn’t know much about USB serial converters yet), plus it still had a bunch of pre-compiled DC homebrew binaries (I was having trouble getting the toolchain to work right).

  The next time I dusted off this machine was late last year when I was trying some experiments with the Microsoft Xbox’s IDE drive (a photo in that post also shows the machine ; this thing shows up a lot on this blog). The VIA machine was the only machine I still owned which had 40-pin IDE connectors which was crucial to my experiment.

  At this point, I was trying to make the machine more useful which meant replacing the ancient Gentoo Linux distribution as well as simply interacting with it via a keyboard and mouse. I have a long Evernote entry documenting a comedy of errors revolving around this little box. The interaction troubles were due to the fact that I didn’t have any PS/2 keyboards left and I couldn’t make a USB keyboard work with it. Diego was able to explain that I needed to flip a bit in the BIOS to address this which worked. As for upgrading the OS, I tried numerous Linux distributions large and small, mostly focusing on the small. None worked. I eventually learned that, while I was trying to use i686 distributions, this machine did not actually qualify as an i686 CPU ; installations usually booted but failed because the default kernel required the cmov instruction. I was advised to try i386 distros instead. My notes don’t indicate whether I had any luck on this front before I gave up and moved on.

  I just made the connection that this VIA machine has two 40-pin IDE connectors which means that the thing was technically capable of supporting up to 4 IDE devices. Obviously, the computer couldn’t really accommodate that in terms of space or power. When I wanted to try installing a new OS, I needed take off the top and connect a rather bulky IDE CD-ROM drive. This computer’s casing was supposed to be able to support a slimline optical drive (perhaps like the type found in laptops), but I could never quite visualize how that was supposed to work, space-wise. When I disassembled the PowerPC Mac Mini, I realized I might be able to repurpose that machines optical drive for this computer. Obviously, I thought better of trying since both machines are off to the recycle pile.

  I would still like to work on the Xbox project a bit more, but I procured a different, unused, much more powerful yet still old computer that has a motherboard with 1 PATA connector in addition to 6 SATA connectors. If I ever get around to toying with Linux kernel development, this should be a much more appropriate platform to use.

  I thought about turning this machine into an old Windows XP (and lower, down to Windows 3.1) gaming platform ; the capabilities of the machine would probably be perfect for a huge portion of my Windows game collection. But I think the lack of an optical drive renders this idea intractable. External USB drives are likely out of the question since there is very little chance that this motherboard featured USB 2.0 (the specs don’t mention 2.0, so the USB ports are probably 1.1).

  So it is with fond memories that I send off both machines, sans hard drives, to the recycle pile. I’m still deciding on an appropriate course of action for failed hard drives, though.

• Dreamcast Serial Extractor

  31 décembre 2017, par Multimedia Mike — Sega Dreamcast

  It has not been a very productive year for blogging. But I started the year by describing an unfinished project that I developed for the Sega Dreamcast, so I may as well end the year the same way. The previous project was a media player. That initiative actually met with some amount of success and could have developed into something interesting if I had kept at it.

  By contrast, this post describes an effort that was ultimately a fool’s errand that I spent way too much time trying to make work.

  Problem Statement
  In my neverending quest to analyze the structure of video games while also hoarding a massive collection of them (though I’m proud to report that I did play at least a few of them this past year), I wanted to be able to extract the data from my many Dreamcast titles, both games and demo discs. I had a tool called the DC Coder’s Cable, a serial cable that enables communication between a Dreamcast and a PC. With the right software, you could dump an entire Dreamcast GD-ROM, which contained a gigabyte worth of sectors.

  Problem : The dumping software (named ‘dreamrip’ and written by noted game hacker BERO) operated in a very basic mode, methodically dumping sector after sector and sending it down the serial cable. This meant that it took about 28 hours to extract all the data on a single disc by running at the maximum speed of 115,200 bits/second, or about 11 kilobytes/second. I wanted to create a faster method.

  The Pitch
  I formed a mental model of dreamrip’s operation that looked like this :

  
  
  

  As an improvement, I envisioned this beautiful architecture :
  

  
  
  

  Architectural Assumptions
  My proposed architecture was predicated on the assumption that the disc reading and serial output functions were both I/O-bound operations and that the CPU would be idle much of the time. My big idea was to use that presumably idle CPU time to compress the sectors before sending them over the wire. As long as the CPU can compress the data faster than 11 kbytes/sec, it should be a win. In order to achieve this, I broke the main program into 3 threads :

  1. The first thread reads the sectors ; more specifically, it asks the drive firmware to please read the sectors and make the data available in system RAM
  2. The second thread waits for sector data to appear in memory and then compresses it
  3. The third thread takes the compressed data when it is ready and shuffles it out through the serial cable

  Simple and elegant, right ?

  For data track compression, I wanted to start with zlib in order to prove the architecture, but then also try bzip2 or lzma. As long as they could compress data faster than the serial port could write it, then it should be a win. For audio track compression, I wanted to use the Flake FLAC encoder. According to my notes, I did get both bzip2 compression and the Flake compressor working on the Dreamcast. I recall choosing Flake over the official FLAC encoder because it was much simpler and had fewer dependencies, always an important consideration for platforms such as this.

  Problems
  I worked for quite awhile on this project. I have a lot of notes recorded but a lot of the problems I had remain a bit vague in my memory. However, there was one problem I discovered that eventually sunk the entire initiative :

  The serial output operation is CPU-bound.

  My initial mental model was that the a buffer could be “handed off” to the serial subsystem and the CPU could go back to doing other work. Nope. Turns out that the CPU was participating at every step of the serial transfer.

  Further, I eventually dug into the serial driver code and learned that there was already some compression taking place via the miniLZO library.

  Lessons Learned

  • Recognize the assumptions that you’re making up front at the start of the project.
  • Prototype in order to ensure plausibility
  • Profile to make sure you’re optimizing the right thing (this is something I have learned again and again).

  Another interesting tidbit from my notes : it doesn’t matter how many sectors you read at a time, the overall speed is roughly the same. I endeavored to read 1000 2048-byte data sectors, 1 or 10 or 100 at a time, or all 1000 at once. My results :

  • 1 : 19442 ms
  • 10 : 19207 ms
  • 100 : 19194 ms
  • 1000 : 19320 ms

  No difference. That surprised me.

  Side Benefits
  At one point, I needed to understand how BERO’s dreamrip software was operating. I knew I used to have the source code but I could no longer find it. Instead, I decided to try to reverse engineer what I needed from the SH-4 binary image that I had. It wasn’t an ELF image ; rather, it was a raw binary meant to be loaded at a particular memory location which makes it extra challenging for ‘objdump’. This led to me asking my most viewed and upvoted question on Stack Overflow : “Disassembling A Flat Binary File Using objdump”. The next day, it also led me to post one of my most upvoted answers when I found the solution elsewhere.

  Strangely, I have since tried out the command line shown in my answer and have been unable to make it work. But people keep upvoting both the question and the answer.

  Eventually this all became moot when I discovered a misplaced copy of the source code on one of my computers.

  I strongly recall binging through the Alias TV show while I was slogging away on this project, so I guess that’s a positive association since I got so many fun screenshots out of it.

  The Final Resolution
  Strangely, I was still determined to make this project work even though the Dreamcast SD adapter arrived for me about halfway through the effort. Part of this was just stubbornness, but part of it was my assumptions about serial port speeds, in particular, my assumption that there was a certain speed-of-light type of limitation on serial port speeds so that the SD adapter, operating over the DC’s serial port, would not be appreciably faster than the serial cable.

  This turned out to be very incorrect. In fact, the SD adapter is capable of extracting an entire gigabyte disc image in 35-40 minutes. This is the method I have since been using to extract Dreamcast disc images.

  The post Dreamcast Serial Extractor first appeared on Breaking Eggs And Making Omelettes.

• How to make Matomo GDPR compliant in 12 steps

  3 avril 2018, par InnoCraft

  Important note : this blog post has been written by digital analysts, not lawyers. The purpose of this article is to briefly show you where Matomo is entering into play within the GDPR process. This work comes from our interpretation of the UK privacy commission : ICO. It cannot be considered as professional legal advice. So as GDPR, this information is subject to change. We strongly advise you to have a look at the different privacy authorities in order to have up to date information.

  The General Data Protection Regulation (EU) 2016/679, also referred to RGPD in French, Datenschutz-Grundverordnung, DS-GVO in German, is a regulation on data protection and privacy for all individuals within the European Union. It concerns organizations worldwide dealing with EU citizens and will come into force on the 25th May 2018.

  The GDPR applies to ‘personal data’ meaning any information relating to an identifiable person who can be directly or indirectly identified in particular by reference to an identifier. It includes cookies, IP addresses, User ID, location, and any other data you may have collected.

  We will list below the 12 steps recommended by the UK privacy commissioner in order to be GDPR compliant and what you need to do for each step.

  The 12 steps of GDPR compliance according to ICO and how it fit with Matomo

  As mentioned in one of our previous blog post about GDPR, if you are not collecting any personal data with Matomo, then you are not concerned about what is written below.

  If you are processing personal data in any way, here are the 12 steps to follow along with some recommendations on how to be GDPR compliant with Matomo :

  1 – Awareness

  Make sure that people within your organization know that you are using Matomo in order to analyze traffic on the website/app. If needed, send them the link to the “What is Matomo ?” page.

  2 – Information you hold

  List all the personal data you are processing with Matomo within your record of processing activities. We are personally using the template provided by ICO which is composed of a set of 30 questions you need to answer regarding your use of Matomo. We have published an article which walks you through the list of questions specifically in the use case of Matomo Analytics. Please be aware that personal data may be also tracked in non-obvious ways for example as part of page URLs or page titles.

  3 – Communicating privacy information

  a – Add a privacy notice

  Add a privacy notice wherever you are using Matomo in order to collect personal data. Please refer to the ICO documentation in order to learn how to write a privacy notice. You can learn more in our article about creating your privacy notice for Matomo Analytics. Make sure that a privacy policy link is always available on your website or app.

  b – Add Matomo to your privacy policy page

  Add Matomo to the list of technologies you are using on your privacy policy page and add all the necessary information to it as requested in the following checklist. To learn more check out our article about Privacy policy.

  4 – Individuals’ rights

  Make sure that your Matomo installation respects all the individuals’ rights. To make it short, you will need to know the features in Matomo that you need to use to respect user rights (right of access, right of rectification, right of erasure…). These features are available starting in Matomo 3.5.0 released on May 8th : GDPR tools for Matomo (User guide).

  5 – Subject access requests

  Make sure that you are able to answer an access request from a data subject for Matomo. For example, when a person would like to access her or his personal data that you have collected about her or him, then you will need to be you able to provide her or him with this information. We recommend you design a process for this like “Who is dealing with it ?” and check that it is working. If you can answer to the nightmare letter, then you are ready. The needed features for this in Matomo will be available soon.

  6 – Lawful basis for processing personal data

  There are different lawful basis you can use under GDPR. It can be either “Legitimate interest” or “Explicit consent”. Do not forget to mention it within your privacy policy page. Read more in our article about lawful basis.

  7 – Consent

  Users should be able to remove their consent at any time. By chance, Matomo is providing a feature in order to do just that : add the opt-out feature to your privacy policy page.
  We are also offering a tool that allows you optionally to require consent before any data is tracked. This will be useful if a person should be only tracked after she or he has given explicit consent to be tracked.

  8 – Children

  If your website or app is targeted for children and you are using Matomo, extra measures will need to be taken. For example you will need to write your privacy policy even more clear and moreover getting parents consent if the child is below 13. As it is a very specific case, we strongly recommend you to follow this link for further information.

  9 – Data breaches

  As you may be collecting personal data with Matomo, you should also check your “data breach procedure” to define if a leak may have consequences on the privacy of the data subject. Please consult ICO’s website for further information.

  10 – Data Protection by Design and Data Protection Impact Assessments

  Ask yourself if you really need to process personal data within Matomo. If the data you are processing within Matomo is sensitive, we strongly recommend you to make a Data Protection Impact Assessment. A software is available from the The open source PIA software helps to carry out data protection impact assessment, by French Privacy Commissioner : CNIL.

  11 – Data Protection Officers

  If you are reading this article and you are the Data Protection Officer (DPO), you will not be concerned by this step. If that’s not the case, your duty is to provide to the DPO (if your business has a DPO) our blog post in order for her or him to ask you questions regarding your use of Matomo. Note that your DPO can also be interested in the different data that Matomo can process : “What data does Matomo track ?” (FAQ).

  12 – International

  Matomo data is hosted wherever you want. So according to the location of the data, you will need to show specific safeguard except for EU. For example regarding the USA, you will have to check if your web hosting platform is registered to the Privacy Shield : privacyshield.gov/list
  Note : our Matomo cloud infrastructure is based in France.

  That’s the end of this blog post. As GDPR is a huge topic, we will release many more blog posts in the upcoming weeks. If there are any Matomo GDPR topic related posts you would like us to write, please feel free to contact us.

  The post How to make Matomo GDPR compliant in 12 steps appeared first on Analytics Platform - Matomo.