The Modern Retrocomputer: An Arduino Driven 6845 CRT Controller

May 14, 2017 by 11 Comments

[MmmmFloorPie] revived an old project to create the retro mashup of a 6845 CRT controller and a modern Arduino Uno. When it comes to chips, the Motorola 6845 is the great granddaddy of Cathode Ray Tube (CRT) interfaces. It was used in the IBM Monochrome display adapter, the Hercules graphics controller, CGA, Apple II terminal cards, and a host of other microcomputer and terminal systems.

Way back in 1989, [MmmmFloorPie] was a senior in college. His capstone project was a 68000 based computer which could record and playback audio, as well as display waveforms on a CRT. The CRT in question was ordered from a classified add in Popular Science magazine. It was a bare tube, so the heavy cardboard box it shipped in was repurposed as a case.

Fast forward to today, and  [MmmmFloorPie] wanted to power up his old project. The 68000 board was dead, and he wasn’t up to debugging the hundreds of point to point soldered connections. The CRT interface was a separate board including the 6845 and 32 KByte of RAM. It would only take a bit of hacking to bring that up. But what would replace the microprocessor?

Continue reading “The Modern Retrocomputer: An Arduino Driven 6845 CRT Controller” →

Patents On MP3 Format Due To Expire

May 14, 2017 by 51 Comments

MP3 took off in the late 90s as the digital music format. It then proceeded to slaughter the CD, and launch the file sharing revolution as well. It’s a proud format that has roots stretching all the way back to the early 1980s, when the possibility of sending music over ISDN lines was first considered. Now the patents on it are beginning to expire and its licencing program has been terminated.

The MP3 standard was the property of Fraunhofer IIS, and the original licencing model was intended such that encoders would be expensive, and decoders relatively inexpensive. This would allow people to buy software to listen to MP3s cheaply, but the creation of MP3s would be expensive, and thus handled by studios and music labels. This all changed when a high-quality MP3 encoder was leaked to the public, and suddenly it became possible to readily convert your CDs at home into the MP3 format.

One hangover of this ownership of the MP3 standard was that when you installed certain FOSS software, such as Audacity or a Linux distro, you would find that you had to go and do some legwork to find an MP3 codec. That was because it wasn’t worth the legal trouble for the FOSS authors to arrange a workaround, and trading in proprietary software is the antithesis to everything they stand for.

However, now that more of the relevant patents are expiring, you can now expect MP3 support to be baked into more software. It may be more than a little late, with more advanced audio formats beginning to take over, but it’s great to know that Fedora, for one, is starting to include MP3 support with their releases.

If you’d like to read more about the history of the MP3, check out this great article from NPR. Fraunhofer have their own great history site, too. If all this talk of advanced audio formats has gotten you excited, check out this MP3 decoder written for the ESP8266.

[Thanks to Tim Trzepacz for the tip!]

VR And Back Again: An XRobots Tale

May 14, 2017 by 8 Comments

Our friend [James Bruton] from XRobots has engaged in another bit of mixed-reality magic by showing how one can seamlessly step from the virtual world into the real world, and back again. Begone, green screens and cumbersome lighting!

Now, most of what you’re seeing is really happening in post-production — for now — but the test footage is the precursor for a more integrated system down the road. As it works now, a GoPro is attached to the front of a HTC Vive headset, allowing [Bruton] to record in both realities at the same time. In the VR test area he has set up is a portal to a virtual green room — only a little smaller than a wardrobe — allowing him to superimpose the GoPro footage over everything he looks at through that doorway, as well as everything surrounding him when he steps through. Unfortunately, [Bruton] is not able to see where he’s going if he is to wear the headset, so he’s forced to hold it in one hand and move about the mixed-reality space. Again, this is temporary.

In action — well, it gets a little surreal when he starts tossing digital blocks through the gateway ‘into’ the real world.

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Better Car Audio With Guitar Effects

May 13, 2017 by 18 Comments

Automotive sound is a huge deal; for many people, it’s the place to listen to music. Back in the 80s, you were lucky to get anything more than two door speakers in the front of the car. Fast forward to today, and you can expect a 10-speaker system in an up-spec’d family sedan.

[Josh] has a car, and wanted to improve the sound. In particular, the aim was to improve the sense of space felt when listening. A car is a relatively small space, and the driver sits in close proximity to the front speakers, so it’s difficult to get a good soundstage.

[Josh]’s approach was to create a “surround” effect for the car stereo, by feeding a left/right difference signal to the rear speakers. This was achieved by the use of a series of op-amps that buffer and then generate a mono signal that represents the difference between the left and right channel. For optimum results, [Josh] wanted to delay the signal being sent to the rear speakers, with a longer delay making the soundstage feel bigger, as if reflections are coming from farther away in a bigger room. To do this, [Josh] simply hooked up the signal to a Boss DD-3 Digital Delay guitar pedal – an off-the-shelf solution to an otherwise sticky problem. The DD-3 gives [Josh] a variable delay time with reasonably high fidelity, so it’s a perfect way to get the project done quickly.

The final piece of the puzzle is a filter. The difference signal doesn’t actually sound all that pleasant to the ears by itself, especially when it comes to transient high-pitched sounds like cymbals, so a lowpass filter is implemented to cut these higher frequencies down.

[Josh] made everything adjustable, from the filter to the delay, so it’s simple to dial things in until they’re just right, rather than relying on calculation or guesswork. The general idea is to feed the difference signal into the rear speakers at a low enough volume and with a subtle delay so that it adds to a general feeling of being in a larger room with the sound coming from all around, as opposed to listening to very loud point sources of audio.

It’s a cool project that we imagine would be very satisfying to dial in and enjoy on the road. What’s more, it’s a fairly straightforward build if you want to experiment with it yourself on your own car. Perhaps your problem is that you need an auxiliary input to your head unit, though – in that case, check out this Subaru project.

A Mini-ITX Atari 800

May 13, 2017 by 21 Comments

As a community has grown up around the 8-bit microcomputers of the 1980s, there have been some beautifully crafted rebuilds of classic machines to take advantage of newer hardware or to interface to peripherals such as keyboards or displays that were unavailable at the time. Often these have taken the form of small boards, or boards that are designed to follow the form factor of the original machine, and fit in an original case.

[mytekcontrols] has taken a different tack with his Atari 800 build, he’s produced an Atari clone designed to take the most popular upgrade boards produced by the 8-bit Atari community, as daughter boards. And he’s followed an existing form factor, though it’s not one from the Atari world. Instead, he’s made it as a mini-ITX motherboard of the type you may well be familiar with from the world of PCs.

He’s calling it the 1088XEL, because with a popular 1MB upgrade board fitted it boasts a generous 1088k of memory. It sports the original five Atari LSI chips, and manages the task without resorting to surface-mount construction.

The forum thread linked above is a long one that makes for a fascinating read as it deals in depth with the design of an 8-bit micro clone. But if you want to skip straight to the hardware, start at about page 13.

We’ve had more than one 8-bit Atari on these pages over the years. Most memorable though is probably this laptop.

Thanks [Lenore Underwood].

Hackaday Prize Entry: A Femtocell Repeater

May 13, 2017 by 9 Comments

For a Hackaday Prize entry, [TegwynTwmffat] is building a cell phone signal repeater. This sort of device is commercially available, but the options are either expensive or, as with some units available for $30 on DealExtreme, obviously noncompliant with RF regulations. This project intends to create a cost-effective, hackable device that works properly and conforms to the right regulations.

The core of this system is a LimeSDR transceiver. This is a board we’ve seen before, and it has a few interesting features. Basically, the core of the LimeSDR is a programmable RF transceiver with coverage from 100kHz to 3.8GHz. There’s also on-chip signal processing and USB 3.0 bandwidth to get the signals to and from a computer.

Right now, [TegwynTwmffat]’s focus is getting his LimeSDR up and working and figuring out how to set up a few radio blocks to do what is needed. There’s a great update to the project that showcases Pothos, and so far [Tegwyn] has a full-duplex repeater working. This is great work, and really showcases the capabilities of what software-defined radio can do.

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Global Cyber Attack Halted: Autopsy Time

May 13, 2017 by 131 Comments

Friday saw what looked like the most dangerous ransomware infection to date. The infection known as WannaCry was closing down vital hospital IT systems across the UK canceling major operations and putting lives at risk.

Spread Halted?

It spread further around the world and almost became a global pandemic. Although machines are still encrypted demanding Bitcoin, one security blogger [MalwareTech] halted the ransomware by accident. As he was analyzing the code he noticed that the malware kept trying to connect to an unregistered domain name “iuqerfsodp9ifjaposdfjhgosurijfaewrwergwea.com”. So he decided to register the domain to see if he could get some analytics or any information the worm was trying to send home. Instead much to his surprise, this halted the spread of the ransomware. Originally he thought this was some kind of kill switch but after further analysis, it became clear that this was a test hard-coded into the malware which was supposed to detect if it was running in a virtual machine. So by registering the domain name, the ransomware has stopped spreading as it thinks the internet is a giant virtual machine.

Why was the UK’s NHS Hit So Badly?

According to the [BBC] Information obtained by software firm Citrix under Freedom of Information laws in December suggest up to 90% of NHS trusts were still using Windows XP, However NHS Digital says it is a “much smaller number”. Microsoft has rolled out a free security update to Windows XP, Windows 8, and Windows Server 2003 “to protect their customers”. There was much warning about XP no longer receiving updates etc, the 2001 operating system just needs to die however so many programs especially embedded devices rely upon the fact that the OS running is Windows XP, This is a problem that needs sorted sooner rather than later. There is still obvious problems facing the NHS as all outpatients appointment’s have been canceled at London’s Barts Health NHS Trust which happens to be the largest in the country. However [Amber Rudd], Home Secretary, said 97% of NHS trusts were “working as normal” and there was no evidence patient data was affected. Let’s just hope they update their systems and get back to fixing people as soon as they can.

Where Else Was Hit?

There was quite a few other places hit as well as the UK’s NHS including The Sunderland Nissan Plant also in the UK, Spanish telecoms giant Telefonica along with some gas companies in Spain. In the US FedEx was affected, France has seen production in some of it’s Renault factories halted. Finally, Russia reported 1000 governmental computer systems has been hit.

So is this the end for ransomware?

No, this infection was stopped by accident the infected are either still infected or have paid up, had they not included the sloppy code in the first place then who knows what would have happened. Microsoft had rolled out patches but some people/organizations/Governments are lazy and don’t bother to apply them. Keep your computers up to date, Good luck because we think we will be seeing a lot more ransomware malware in the coming years.

[Update WannaCry v. 2.0 has been released without the “kill switch”, We wonder what will happen now. Probably not a lot as the media attention has been quite intense so it may not be that big an infection however there is always a few who live in the land where news doesn’t exist and will go a long their day until BAM! Ransom Ware installed and pockets emptied.]