computer hacks

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computer hacks

ODROID XU4 Runs Cool As Water

October 28, 2016 by 11 Comments

We did a bit of looking through the ODROID forums and apparently it’s quite possible to squeeze an impressive amount of performance out of these little single board computers, if you don’t mind them getting boiling hot.

Now, some people have taken pedestrian routes. It’s a low power single board computer after all. A bigger heatsink or a fan appears to be enough for most. [Micky] and a friend, however, decided this is a problem that can only be solved with a healthy bit of overengineering.

Using a water cooler meant for a full CPU, a modified chipset cooling block (meant for the North or South Bridge), a liberal application of plexiglass, and some thermal paste they manage to triple the cost of their computer set-up with this wonderfully overkill desk ornament.

Now it can do all the things a Raspberry Pi can do, faster and watercooled.

When Your Screen Breaks In The Himalayas

October 24, 2016 by 26 Comments

If you’ve ever had the screen break on your laptop, you’ll know it can be rather annoying to have to use an external monitor for a while as you either wait for a replacement panel to arrive from the other side of the world, or wait for that new laptop you were just desperate for an excuse to upgrade to.

Spare a thought, then, for [tom bh] whose laptop screen broke while he was in Ladakh, Northern India. Two days bus ride from the nearest city in which he could hope to source a replacement part, he had to make do with the resources in front of him. A laptop with a broken screen, and his Android phone.

He was fortunate in that a few lines at the top of the screen still worked intermittently. So after logging in blind and finding himself in a shell, he could execute commands and then scroll the results up to the point at which they were visible. He first enabled an SSH server, then connected his phone via USB. A bit of work to find the laptop’s IP address, and he could get himself a laptop shell on his phone with an Android SSH client. He goes into detail about how he was able to use the laptop’s keyboard to emulate a Bluetooth device which he connected to the phone. He could then run a VNC server on the laptop and connect to it with a VNC client on the phone, resulting in a phone-sized laptop display using the laptop’s keyboard as input. Not a perfect physical terminal by any means, but enough for him to continue working.

His writeup is an especially interesting read for its side-by-side evaluation of the various different application choices he made, and contains some useful suggestions as to how anyone might prepare themselves for a dead screen related emergency.

We’ve featured a dead-screen laptop connected as a serial terminal with an Arduino in the past, but unlike this one that only gave its owner a prompt.

Via Hacker News.

Making A Cassette Mass Storage Interface

October 22, 2016 by 55 Comments

If you are of the generation who were lucky enough to use the first 8-bit home computers in your youth, you will be familiar with their use of cassette tapes as mass storage. Serial data would be converted to a sequence of tones which could then be recorded using a standard domestic cassette recorder, this recording could then be played back into the machine’s decoder and loaded into memory as a complete piece of software. Larger programs could take a while to load, but though it was rather clunky it was a masterful piece of making the best of what was at hand.

[Mike Kohn] was working with some microcontroller infra-red communication projects when he saw that the same techniques could be used to produce a tape interface like those on the home computers of old.

Over the years he has returned to the project a couple of times, and his original Atmel processor has been supplanted by a W65C265SXB development board based on the 16-bit derivative of the 6502. This made generating the tones as straightforward using his processor’s built-in tone generator, but decoding still presented a challenge. His earlier attempts used an LM2917 frequency to voltage converter to decode tones to logic levels, but on further consideration he decided to move to the LM567 tone decoder. This chip is designed specifically for an on-off logic output rather than the 2917’s analogue voltage output.

His recording device was originally a hi-fi separate cassette deck after experimenting with microcassettes, but eventually he used a data recorder designed for a Radio Shack TRS-80. All his code can be found in his GitHub repository.

It’s probably true to say that [Mike] has made a better cassette interface than the one you could have found on your home computer back in the day. We’ve featured a few data cassette hacks over the years, including this Commodore tape deck with an LED counter, and a tape deck emulator capable of holding an entire software archive.

Hook Any Mouse To An Acorn

October 22, 2016 by 16 Comments

Acorn was one of the great IT giants that rose high and then fell to obscurity during the rise of personal computing. However, for many hobbyists these computers are as important and as loved as the Commodore 64. [Simon Inns] has made a great adapter to interface modern USB mice to these old boxes. 

After thirty years of interaction with people, one might be hard pressed to find a working mouse for an older computer. On top of that, even if you did, these mice are likely a lackluster experience to begin with. They were made long before industrial designers were invited to play with computers and are often frustrating and weird. Cotton swabs and alcohol are involved, to say the least.

[Simon]’s box converts a regular USB HID compliant mouse to a quadrature signal that these 8-bit computers like. The computer then counts the fake pulses and happily moves the cursor around. No stranger to useful conversion boxes, he used an Atmel micro (AT90USB1287) with a good set of USB peripherals. It’s all nicely packed into a project box. There’s a switch on the front to select between emulation modes.

If you’d like one for yourself the code and schematics are available on his site. As you can see in the video below, the device works well!

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Make Any PC A Thousand Dollar Gaming Rig With Cloud Gaming

October 19, 2016 by 71 Comments

The best gaming platform is a cloud server with a $4,000 dollar graphics card you can rent when you need it.

[Larry] has  done this sort of thing before with Amazon’s EC2, but recently Microsoft has been offering a beta access to some of NVIDIA’s Tesla M60 graphics cards. As long as you have a fairly beefy connection that can support 30 Mbps of streaming data, you can play just about any imaginable game at 60fps on the ultimate settings.

It takes a bit of configuration magic and quite a few different utilities to get it all going, but in the end [Larry] is able to play Overwatch on max settings at a nice 60fps for $1.56 an hour. Considering that just buying the graphics card alone will set you back 2500 hours of play time, for the casual gamer, this is a great deal.

It’s interesting to see computers start to become a rentable resource. People have been attempting streaming computers for a while now, but this one is seriously impressive. With such a powerful graphics card you could use this for anything intensive, need a super high-powered video editing station for a day or two? A CAD station to make anyone jealous? Just pay a few dollars of cloud time and get to it!

Custom Keyboard Makes The Case For Concrete

October 4, 2016 by 38 Comments

One of the worst things about your average modern keyboards is that they have a tendency to slide around on the desk. And why wouldn’t they? They’re just membrane keyboards encased in cheap, thin plastic. Good for portability, bad for actually typing once you get wherever you’re going.

When [ipee9932cd] last built a keyboard, finding the right case was crucial. And it never happened. [ipee9932cd] did what any of us would do and made a custom case out of the heaviest, most widely available casting material: concrete.

To start, [ipee9932cd] made a form out of melamine and poured 12 pounds of concrete over a foam rectangle that represents the keyboard. The edges of the form were caulked so that the case edges would come out round. Here’s the super clever part: adding a couple of LEGO blocks to make space for the USB cable and reset switch. After the concrete cured, it was sanded up to 20,000 grit and sealed to keep out sweat and Mountain Dew Code Red. We can’t imagine that it’s very comfortable to use, but it does look to be cool on the wrists. Check out the gallery after the break.

Concrete is quite the versatile building material. We’ve seen many applications for it from the turntable to the coffee table to the lathe.

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Hack An 8085 Like It’s 1985

October 1, 2016 by 23 Comments

If you have been building electronic hardware for several decades, do you still have any projects from your distant past? Do they work? An audio amplifier perhaps, or a bench power supply.

[Just4Fun] made a rather special computer in the 1980s, and it definitely still works. Describing it as “An 8085 single board computer with an EPROM emulator” though, does not convey just how special it is. This is not the modern sense of a single board computer with an SoC and a few support components. Instead it is a full system in the manner of the day in which processor, memory and peripherals are all separate components surrounded by 74 series glue logic. The whole system is wire-wrapped on a piece of perfboard and mounted very neatly in a rack. The EPROM emulator is a separate unit in a console case with hexadecimal keyboard and 7-segment display.

As the video below the break of an LED flashing demo shows, the EPROM emulator allows 8085 machine code to be entered byte by byte instead of having to be burned into a real EPROM.

[Just4Fun] leaves us with plans to replace the period EPROM emulator with a modern alternative, an EEPROM on a PCB designed to fit in the original bank of EPROM sockets. In this he suggests he might fit a bootloader and a BASIC interpreter, something entirely possible back in the day with conventional EPROMs, but probably not as cheaply.

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