Hardware Archive

The Z-80 has a 4-bit ALU – here’s how it works

Thom Holwerda 2013-09-07 Hardware 28 Comments

The 8-bit Z-80 processor is famed for use in many early personal computers such the Osborne 1, TRS-80, and Sinclair ZX Spectrum, and it is still used in embedded systems and TI graphing calculators. I had always assumed that the ALU (arithmetic-logic unit) in the Z-80 was 8 bits wide, like just about every other 8-bit processor. But while reverse-engineering the Z-80, I was shocked to discover the ALU is only 4 bits wide! The founders of Zilog mentioned the 4-bit ALU in a very interesting discussion at the Computer History Museum, so it's not exactly a secret, but it's not well-known either.

I have been reverse-engineering the Z-80 processor using images from the Visual 6502 team. The image below shows the overall structure of the Z-80 chip and the location of the ALU. The remainder of this article dives into the details of the ALU: its architecture, how it works, and exactly how it is implemented.

Ken Shirrif's blog is an absolute must for fans of ultra-low-level hardware stuff. This goes way over my head, but interesting nonetheless.

Photos of Samsung’s Galaxy Gear smartwatch leak

Thom Holwerda 2013-09-01 Hardware 66 Comments

Samsung is set to reveal its Galaxy Gear smartwatch next Wednesday, Sept. 4, in Berlin. But this weekend, we got a first look at the watch.

Here it is.

I love watches (I have several watches for different occasions and clothing styles), but this thing looks ridiculous. A three inch contraption shaped like a Galaxy phone strapped to my tiny wrist?

What?

D-Wave’s quantum optimizer might be quantum after all

Thom Holwerda 2013-07-01 Hardware No Comments

"Quantum optimizer manufacturer D-Wave Systems has been gaining a lot of traction recently. They've sold systems to Lockheed Martin and Google, and started producing results showing that their system can solve problems that are getting closer to having real-life applications. All in all, they have come a long way since the first hype-filled announcement. Over time, my skepticism has waxed and waned. Although I didn't really trust their demonstrations, D-Wave's papers, which usually made more limited claims, seemed pretty solid. Now, there is a new data point to add to the list, with a paper claiming to show that the D-Wave machine cannot be doing classical simulated annealing."

Samsung Ativ Q: Windows 8 and Android hybrid laptop

Thom Holwerda 2013-06-21 Hardware 9 Comments

"Samsung has just announced one of its latest laptops: the Ativ Q. It dual-boots Android 4.2.2 and Windows 8 in a 13.3-inch device with a super high-resolution display running at 3200 x 1800. Samsung has bundled in its S Pen stylus in a magnesium device. It looks like Acer's Aspire R7, but it's .55 inches and 2.84 pounds so it feels a lot lighter. The Ativ Q has a unique feature that lets it switch to Android from within Windows 8. It appears to be an application that virtualizes the Android experience, with an app pinned to the Windows 8 Start Screen that launches straight into Android. It runs fullscreen, but it's not usable it you try to snap it to the side and continue using a Windows 8 app." Do these dual-operating system things ever sell? It does illustrate how Windows OEMs are struggling with the fact that people don't want Windows 8 - they have to tack Android on there to lure people.

Asus releases massive 31.5″ 3840×2160 monitor

Thom Holwerda 2013-05-31 Hardware 36 Comments

"Asus has just announced the cure for the common 20-something-inch 1080p display: a small TV-sized 31.5-inch monitor with a massive resolution of 3840x2160. Engadget reports that the Asus PQ321 display, which uses IGZO technology to reduce energy usage and thickness, includes DisplayPort and dual-HDMI input, integrated speakers, and an adjustable stand." The dread of 1366 and 1080p is being removed. Finally.

Guest post by MOS6510 2013-05-17 Hardware 25 Comments

"It is good for programmers to understand what goes on inside a processor. The CPU is at the heart of our career. What goes on inside the CPU? How long does it take for one instruction to run? What does it mean when a new CPU has a 12-stage pipeline, or 18-stage pipeline, or even a 'deep' 31-stage pipeline? Programs generally treat the CPU as a black box. Instructions go into the box in order, instructions come out of the box in order, and some processing magic happens inside. As a programmer, it is useful to learn what happens inside the box. This is especially true if you will be working on tasks like program optimization. If you don't know what is going on inside the CPU, how can you optimize for it? This article is about what goes on inside the x86 processor's deep pipeline."

Review: high-PPI Toshiba Kirabook

Thom Holwerda 2013-05-15 Hardware 20 Comments

"We're sure that more high-density Windows laptops are on the way, but the Kirabook is the first to make it to market. The laptop raises some natural questions: Does a computer that is both thinner and lighter than the Pixel and the Pros skimp on battery life to achieve these feats? Is the Kirabook good enough to justify its jaw-dropping $1,599.99 starting price? Most importantly, can Windows support high-density displays as well as OS X, Chrome OS, iOS, Android, and others can?" Great laptop, great screen, decent battery life - but Windows' scaling is a terrible mess. Metro is fine, but the proper desktop is a disaster.

Sony bans 1366×768 from notebook lineup

Thom Holwerda 2013-05-07 Hardware 66 Comments

News of the year in the technology industry. "The Fit's most important spec its display, with a nod to Sony's TV division: they come with 1600x900 or 1920x1080 touchscreens and nothing else. 'We're not going to offer 1366x768," reps said. 'We've killed that.'" This is Sony's new, simplified entry-level notebook line. Very, very welcome news in a world where even a supposedly "Pro" laptop that costs $1199 ships with... A 1280x800 resolution. This bottom-of-the-barrel crap needs to be eradicated, and good on Sony for taking this step.

NeXT Computer

Thom Holwerda 2013-05-04 Hardware 64 Comments

"NeXT Computer (the original 68030 cube) was a high end workstation that was manufactured between 1988 - 1990. Back then it was a very expensive machine as a complete system would start at $6500 (in 1988 dollars). The machine is a 1 foot cube magnesium case that houses the computer. At the time, its performance was impressive, with a Motorola 68030 CPU running at a screaming 25Mhz, a dedicated floating point CPU, and a digital signal processor built into the system. NeXT cubes featured a magneto-optical drive that stored a whopping 256 Megabytes (by comparison, high end Mac systems at the time might have featured a 20 Megabyte hard drive.) In its day, this was the "Ferrari" of desktop systems!" No new information for the average OSNews reader, but lots of beautiful photos for a beautiful Saturday afternoon.

IDC: Android now leads the tablet market with a 56.5% share

Thom Holwerda 2013-05-01 Hardware 42 Comments

"The Q1 2013 numbers from IDC, a technology and telecommunications research firm who keeps track of this sort of thing, show that Android tablets now lead the market with a 56.5-percent share. The 27,800,000 units shipped in the quarter is a 247-percent improvement from this time last year, when just 8,000,000 units were shipped. It's important to note that this increase doesn't come at the expense of Apple, who shipped 65.3-percent more tablets in Q1 2013 than they did in Q1 2012 - it shows the market is growing, and the lions share of new purchases are Android." While Android's market share growth scares me, it's good that it's not really harming the competition. Also, maybe this will be the carrot for developers to improve Android tablet applications.

Guest post by MOS6510 2013-04-27 Hardware 30 Comments

"One of the things that will never fail to make me happy: seeing people stuck in time explain what modern day technology is. Kim Komando hosted an educational series about computer and explains the basics of its hardware, DOS, Microsoft Windows, Writeand more."

Connecting an iPad Retina LCD to a PC

Thom Holwerda 2013-04-22 Hardware 12 Comments

"What is great about this panel (except its resolution) is that it has an eDisplayPort interface (which is supposed to replace LVDS in the near future), and as this hack proves it is compatible with traditional DisplayPort outputs found on all modern video cards. The panel is also surprisingly cheap - I got mine on ebay for $55, shipped from China. Hoping that eDisplayPort is compatible with regular DisplayPort (I couldn't find conclusive proof of this), I went on to interface the panel with a DP cable." Cool.

Ancient computers in use today

Thom Holwerda 2013-04-17 Hardware 42 Comments

"While much of the tech world views a two-year-old smartphone as hopelessly obsolete, large swaths of our transportation and military infrastructure, some modern businesses, and even a few computer programmers rely daily on technology that hasn't been updated for decades." Back when I still worked at a hardware and plumbing store - up until about 4-5 years ago - we used MS-DOS cash registers. They are still in use today. If it works, it works.

A file system all its own

Thom Holwerda 2013-04-14 Hardware 36 Comments

"In the past five years, flash memory has progressed from a promising accelerator, whose place in the data center was still uncertain, to an established enterprise component for storing performance-critical data. It's rise to prominence followed its proliferation in the consumer world and the volume economics that followed. With SSDs, flash arrived in a form optimized for compatibility - just replace a hard drive with an SSD for radically better performance. But the properties of the NAND flash memory used by SSDs differ significantly from those of the magnetic media in the hard drives they often displace. While SSDs have become more pervasive in a variety of uses, the industry has only just started to design storage systems that embrace the nuances of flash memory. As it escapes the confines of compatibility, significant improvements in performance, reliability, and cost are possible."

Alienware unveils Ubuntu gaming PC

Thom Holwerda 2013-04-05 Hardware 41 Comments

AlienWare (so Dell) has just unveiled a gaming PC running Ubuntu and Steam, designed to be hooked up to a TV - essentially a Steambox. "With over 25 gaming titles available and more being added, users can access Steam For Linux to play online games, including your favorite titles like Team Fortress 2 and Serious Sam 3." Everything starts out small, but with Valve going full throttle with this, expect this library to grow.

A strange computer promises great speed

Thom Holwerda 2013-03-22 Hardware 49 Comments

"But a powerful new type of computer that is about to be commercially deployed by a major American military contractor is taking computing into the strange, subatomic realm of quantum mechanics. In that infinitesimal neighborhood, common sense logic no longer seems to apply. A one can be a one, or it can be a one and a zero and everything in between - all at the same time. Now, Lockheed Martin - which bought an early version of such a computer from the Canadian company D-Wave Systems two years ago - is confident enough in the technology to upgrade it to commercial scale, becoming the first company to use quantum computing as part of its business." I always get a bit skeptical whenever I hear the words 'quantum computing', but according to NewScientist, this is pretty legit.

Submitted by Laurence 2013-03-05 Hardware 16 Comments

Steve Mann on his 35-year history building and wearing computerised eyewear. "Was it blind luck (pardon the expression) that I was wearing this vision-enhancing system at the time of the accident? Not at all: I have been designing, building, and wearing some form of this gear for more than 35 years." Glass has the potential to have a huge impact on the world - and just like with the advent of the mobile phone, people are afraid, cynical, and unable to see the possibly huge benefits of systems like this.

Submitted by MOS6510 2013-02-11 Hardware No Comments

"The story of how the Colossus computer at Bletchley Park aided the allied code-cracking effort during World War II is becoming well known. Its claim to be a forerunner of modern-day computers is also well established. What is much less well known is the tale of how Colossus's story came to be told in the first place. It is a tale of how one man's dogged efforts overcame official secrets and official indifference to rewrite computer history. Computer scientist Brian Randell was the man who started uncovering the history of Colossus."

Submitted by Nth_Man 2013-02-10 Hardware 18 Comments

" bricked a Samsung laptop today. Unlike most of the reported cases of Samsung laptops refusing to boot, I never booted Linux on it - all experimentation was performed under Windows. It seems that the bug we've been seeing is simultaneously simpler in some ways and more complicated in others than we'd previously realised." On a related note, the Linux Foundation's UEFI secure boot system has been released.

Dell goes private

Thom Holwerda 2013-02-05 Hardware 30 Comments

"Dell today announced it has signed a definitive merger agreement under which Michael Dell, Dell's Founder, Chairman and Chief Executive Officer, in partnership with global technology investment firm Silver Lake, will acquire Dell." So, Dell has gone private, and Microsoft has contributed a $2 billion loan to the deal.