Dump Your (Old) Computer’s ROM Using Audacity

April 12, 2016 by Elliot Williams 32 Comments

If you’ve got an old calculator, Commodore 64, or any other device that used a tape recorder to store and retrieve data, you’ve probably also got a bunch of cassettes lying around, right? Well, you can get rid of them now (or sell them to nostalgic collectors for outrageous prices) because you can just as easily dump them to Audacity, decode them and archive them on a more sane medium.

In [Kai]’s case, the computer was a Sharp Pocket Computer system, and in his post there’s a lot of detail that’s specific to that particular system. If that’s applicable to you, go read up. In particular, you’ll be glad to find that the Pocket-Tools is a software suite that will encode and decode files between the Sharp binary formats and audio. Along the way, we found similar tools for Casio pocket computers too.

For a more general-purpose approach, like if you’re trying to dump and load data from a more standard computer that uses 1200/2400 Hz FSK encoding, this Python library may be useful, or you can implement the Goerzel algorithm yourself on your platform of choice. If you’ve got a particular binary format in mind, though, you’ll have to do the grunt work yourself.

Anyone out there still using these audio data encodings? We know that ham radio’s APRS system runs on two tones. What else? Why and when would you ever transfer data this way these days?

via the Adafruit blog!

Wooden Computer Case Adds A Touch Of Modern

March 30, 2016 by James Hobson 20 Comments

When [LouisVW] decided to build a new gaming rig, he wanted to try something different. So instead of buying a pre-built tower, he made one — out of wood!

Coming from someone who has no experience in woodworking (or computer building) we’re seriously impressed with what he’s made. He was originally inspired to build the case when he saw boxes made by stacking pieces of plywood together — he got one and decided to turn it into a case.

Using a jigsaw, chisel and Dremel he was able to cut out all of the fan holes and drive bays fairly easily, and thanks to overlapping plastic covers it wasn’t that hard to make everything look perfect.
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Peering Inside The GPU Black Box

March 30, 2016 by Elliot Williams 27 Comments

Researchers at Binghamton University have built their own graphics processor unit (GPU) that can be flashed into an FGPA. While “graphics” is in the name, this GPU design aims to provide a general-purpose computing peripheral, a GPGPU testbed. Of course, that doesn’t mean that you can’t play Quake (slowly) on it.

The Binghamton crew’s design is not only open, but easily modifiable. It’s a GPGPU where you not only know what’s going on inside the silicon, but also have open-source drivers and interfaces. As Prof. [Timothy Miller] says,

It was bad for the open-source community that GPU manufacturers had all decided to keep their chip specifications secret. That prevented open source developers from writing software that could utilize that hardware. With contributions from the ‘open hardware’ community, we can incorporate more creative ideas and produce an increasingly better tool.

That’s where you come in. [Jeff Bush], a member of the team, has a great blog with a detailed walk-through of a known GPU design. All of the Verilog and C++ code is up on [Jeff]’s GitHub, including documentation.

If you’re interested in the deep magic that goes on inside GPUs, here’s a great way to peek inside the black box.

Crawl, Walk, Run: A Starter CPU

March 25, 2016 by Al Williams 3 Comments

Last time I talked about getting started with CPU design by looking at older designs before trying to tackle a more modern architecture. In particular, I recommended Caxton Foster’s Blue, even though (or maybe because) it was in schematic form. Even though the schematics are easy to understand, Blue does use a few dated constructs and you probably ought to build your take on the design using your choice of VHDL or Verilog.

In my case, my choice was Verilog. You can find my implementation of Blue on Opencores.org. I made quite a few changes to Foster’s original design. For example, armed with semiconductor memory, I managed to get all instructions to operate in one major cycle (which is, of course, 8 minor cycles). I also modernized the clock generation and added some resources and instructions.

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Kestrel Computer Project

March 25, 2016 by Brandon Dunson 29 Comments

Many successful large-scale projects don’t start out large: they start with a small working core and grow out from there. Building a completely open-source personal computer is not a weekend project. This is as much a retelling of events as it is background information leading up to a request for help. You’ll discover that quite a lot of hard work has already been put forth towards the creation of a completely open personal computer.

When I noticed the Kestrel Computer Project had been submitted via the Hackaday tips line I quickly tracked down and contacted [Samuel] and asked a swarm of questions with the excitement of a giddy schoolgirl. Throughout our email conversation I discovered that [Samuel] had largely kept the project under the radar because he enjoyed working on it in his down time as a hobby. Now that the project is approaching the need for hardware design, I posed a question to [Samuel]: “Do you want me to write a short article summarizing years of your work on Kestrel Project?” But before he could reply to that question I followed it up with another: “Better yet [Samuel], how about we tell a more thorough history of the Kestrel Project and ask the Hackaday community for some help bringing the project home!?”
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5 Wide And Tall Monitors With Hacked Bezels For Wall Of Awesome

March 20, 2016 by Richard Baguley 17 Comments

If two is better than one, what about five? [Omnicrash] has posted a nice analysis of his monitor setup, which uses 5 portrait mounted monitors side-by-side. To minimize the bezel size between them, he removed the casing and built a custom stand that placed them all closely together for a surround viewing approach. He’s been using this setup for a couple of years and has posted a nice analysis of making it work for multiple purposes. On the upside, he says it is awesome for gaming and watching videos.

On the downside, NVidia’s drivers and multi-monitor setup are a pain, and some tasks just didn’t work with the bezels. He couldn’t, for instance, run a standard-sized remote desktop screen anywhere without having the bezel get in the way. So, with large, hi-res monitors now getting cheaper, would he do it again? “If I had to do it all over again nowadays however I’d probably just go with a single 34″ ultra-wide for about the same price..though I probably wouldn’t be able to help myself and would eventually be adding at least one on top and 2 in portrait on the side.”

Thanks For The Memories: Touring The Awesome Random Access Of Old

March 8, 2016 by Al Williams 41 Comments

I was buying a new laptop the other day and had to make a choice between 4GB of memory and 8. I can remember how big a deal it was when a TRS-80 went from 4K (that’s .000004 GB, if you are counting) to 48K. Today just about all RAM (at least in PCs) is dynamic–it relies on tiny capacitors to hold a charge. The downside to that is that the RAM is unavailable sometimes while the capacitors get refreshed. The upside is you can inexpensively pack lots of bits into a small area. All of the common memory you plug into a PC motherboard–DDR, DDR2, SDRAM, RDRAM, and so on–are types of dynamic memory.

The other kind of common RAM you see is static. This is more or less an array of flip flops. They don’t require refreshing, but a static RAM cell is much larger than an equivalent bit of dynamic memory, so static memory is much less dense than dynamic. Static RAM lives in your PC, too, as cache memory where speed is important.

For now, at least, these two types of RAM technology dominate the market for fast random access read/write memory. Sure, there are a few new technologies that could gain wider usage. There’s also things like flash memory that are useful, but can’t displace regular RAM because of speed, durability, or complex write cycles. However, computers didn’t always use static and dynamic RAM. In fact, they are relatively newcomers to the scene. What did early computers use for fast read/write storage?

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