The Practical Approach to Keeping Your Laser in Focus
You could be forgiven for thinking that laser cutters and engravers are purely two dimensionalRead More
Cop Awarded $585K After ‘Dozens’ Of Police Officers Accessed Their DMV Data 500 Times
Slashdot reader Iwastheone shares a story from Ars Technica about what happened after Minnesota’s DepartmentRead More
:Syslog.gr: - a Site about Computers, Open Source, Security, SysAdmins and more ...
The Commodore 64 was the highest selling computer of all time, and will likely forever remain that way due to the fragmentation of models in the market ever since. Due to this, it’s hardly surprising that it still has a strong following many years after its heyday. This means that the avid restorer has a wide range of parts and support available at the click of a button. [DusteD] is just one such person who had a busted-up C64 laying around, and decided to make it a project.
[DusteD] wanted to reuse the original case, and decided it should remain a Commodore 64 after an initial attempt at a mini-ITX swap went awry. Desiring a reliable machine, an Ultimate64 FPGA board was selected to replace the original faulty motherboard. This has the benefit of being hardware compatible with the classic C64, while allowing [DusteD] to tinker and program to his heart’s content, without having to worry about blowing up valuable original parts. It also provides several interesting modern features, like HDMI output, USB, and even Ethernet connectivity. This allows one to experiment with the platform without the hassles of all the inherent limitations of 1980s technology.
As a fan of the classic SID sound chip, [DusteD] was also highly interested in the audio output of the Ultimate64. Recordings were made of the emulated output from the FPGA, as well as the sound output from a real SID installed in the board, both through the mixed output and directly from the chip via a SIDTAP. Those interested can download the 800MB of recordings and compare the output; there’s a summary of the differences noted listed on the site as well.
[DusteD] makes a great argument for the benefits of building up a C64 rig in this way. It’s a great way to get started for those eager to explore the world of Commodore’s 8-bit hardware without the hassles and expenses of buying all the real gear. As it stands, the C64 aftermarket is so advanced now, that you can build an entirely new machine from scratch if you so desire. Go forth and enjoy!
As America’s antitrust investigators eye Google, Apple, Facebook, and Amazon for possible government intervention, Bloomberg offers nine “lessons learned” from the way Microsoft handled its own antitrust investigation:
Don’t deny the obvious… In the app-store business, Google and iPhone maker Apple together control more than 95 per cent of all US mobile app spending by consumers, according to Sensor Tower data. It could be more effective for these companies not to start by denying that leadership position — if you have 80% or 90% percent of a market, arguing that you don’t really dominate isn’t the hill you want your legal reasoning to die on…
At the height of Microsoft’s hubris (or carelessness, or both), the company sent Windows chief Jim Allchin to the stand with a doctored video that purported to show how computing performance would be degraded when the browser was removed from Windows on a single PC. It was actually done on several different computers and was an illustration of what might happen rather than a factual test, as the company initially claimed — a fact that came to light only after several days of the government picking through every inconsistency in the video. Microsoft remade the simulation several times in an effort to save the testimony. The company seemed to think it could get away with baldy stating a technological claim and mocking up something that backed it up, perhaps reasoning that no one would know the difference, but it miscalculated badly…
In an interview last year at the Code Conference, Microsoft President and Chief Legal Officer Brad Smith lamented the distraction the case caused, and cited it as a reason the company missed out on the search market — the business that fueled the runaway success of Google, now under the microscope itself. Others have pinned Microsoft’s abysmal performance in mobile computing partially on constraints and distractions from the case…
Consider settling early.
The article also remembers leaks of Bill Gates deposition (“During their playback in court, the judge laughed at several points”) and ultimately concludes that “observers and legal pundits almost uniformly agree the software giant did virtually everything wrong in the course of the investigation.” A federal judge ordered Microsoft be split in two, “a fate Microsoft avoided when an appeals court reversed that part of the ruling and the company eventually settled.”
“That 2002 settlement led to nine years of court supervision of the company’s business practices and required Microsoft to give the top 20 computer makers identical contract terms for licensing Windows, and gave computer makers greater freedom to promote non-Microsoft products like browsers and media-playing software…”
of this story at Slashdot.
Most of us have a pretty simple model of how a computer works. The CPU fetches instructions and data from memory, executes them, and writes data back to memory. That model is a good enough abstraction for most of what we do, but it hasn’t really been true for a long time on anything but the simplest computers. A modern computer’s memory subsystem is much more complex and often is the key to unlocking real performance. [Pdziepak] has a great post about how to take practical advantage of modern caching to improve high-performance code.
If you go back to 1956, [Tom Kilburn’s] Atlas computer introduced virtual memory based on the work of a doctoral thesis by [Fritz-Rudolf Güntsch]. The idea is that a small amount of high-speed memory holds pieces of a larger memory device like a memory drum, tape, or disk. If a program accesses a piece of memory that is not in the high-speed memory, the system reads from the mass storage device, after possibly making room by writing some part of working memory back out to the mass storage device.
Caching takes this even further. The CPU executes code from a small but very fast cache. A larger and slower cache acts as mass storage for the fast cache. That cache may have its own cache until eventually one of the caches empties into a mass storage device. Naturally, there are some differences since the purpose is different: cache is mainly concerned with faster memory access while virtual memory tries to allow large programs to run in less physical memory.
However, this is a lot different than our common mental model. In a very real sense, today’s modern CPUs execute programs from mass storage. That’s why you can have many huge programs running on a single computer with limited memory. However, the CPU really executes from a very small high-speed memory.
A modern cache is often split into separate parts for instruction and data, and [Pdziepak] is looking specifically at the level 1 instruction cache. It gets pretty detailed, but it does talk about tools to examine cache performance and also about hot and cold functions, something we don’t think gets enough use.
Of course, if you are just writing normal code, you probably don’t care. But if you are trying to wring the most performance you can get out of your CPU, you’ll enjoy the post.
“Delta Air Lines announced it will give passengers who fly out of Minneapolis-St. Paul International Airport the option to use facial recognition to board their flight instead of a standard boarding pass,” reported a CBS affiliate this week.
The facial scanners will be installed this week at 16 gates, with availability on all international flights through Delta beginning in July. The airline is working with Customs and Border Protection on the process. The way it works is gate agents use facial scans for boarding passengers so that they don’t need to manually compare their faces and their passport photos. They can skip to using the facial technology. Delta says the process saves about two seconds per passenger or about nine minutes for a plane with 270 people.
Delta says 72% of its customers have said they prefer facial recognition to standard boarding procedures. But James Lileks, a columnist for the Star Tribune, explains some of the ways this makes him uncomfortable:
Here’s the thing. You don’t sign up for the facial recognition. You don’t send them your face. They already have it. This part is just… glided over in the news reports, waved away like a minor detail you needn’t worry your silly little head about.
The picture they probably have is my passport photo, taken in 2010… So I guess I’ll have to stuff my cheeks with cotton before I lean into the machine that connects to a database of everyone’s mug, and hope it doesn’t go off
“I don’t know what they do with people who grew a beard,” Lileks adds, “but there’s probably the option to shave on the spot.”
of this story at Slashdot.
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