Don’t Mess With Texas – The TI-99/4A Megademo

January 30, 2017 by 18 Comments

The demoscene is a hotbed of masterful assembly programming, particularly when it comes to platforms long forgotten by the passage of technology and time. There’s a certain thrill to be had in wringing every last drop of performance out of old silicon, particularly if it’s in a less popular machine. It’s that mindset that created Don’t Mess With Texas – a glorious megademo running on the TI-99/4A.

Entered in the oldskool demo contest at Syncrony 2017, the demo took out the win for [DESiRE], a group primarily known for demos on the Amiga – a far more popular platform in the scene. The demo even includes a Boing Ball effect as a cheeky nod to their roots. Like any good megademo, the different personalities and tastes brings a huge variety of effects to the show – there’s a great take on vintage shooters a la Wolfenstein in there too. [jmph] shared a few more details on the development process over on pouet.net.

The TI-99/4A wasn’t the easiest machine to develop for. It’s got a 16-bit CPU hamstrung by an 8-bit bus, and only 256 bytes of general purpose RAM. Despite the group’s best attempts, the common 32K RAM expansion present in the floppy drive controller is a requirement to run the demo. Just to make things harder, the in-built BASIC is too slow for any real use and there’s no function to allow the use of in-line assembly instructions. The group had to resort to a cartridge-based assembler to get the job done.

In the machine’s favour, it has a great sound chip put to brilliant use – the demo’s soundtrack will take you right back to the glory days of chiptune. It’s also got strong graphics capabilities for the era on par with, if not better than, the Commodore 64. The video subsystem in the TI works so hard that it’s the only DIP in the machine that gets a heatsink! The demo does a great job of pushing the machine to its limits in this regard.

If you’re suddenly feeling a strong attraction to the TI-99/4A, don’t worry – it’s got a cult following all its own. You can even find USB adapters & IDE controllers if you want to build a fully loaded rig, or play a stunning port of Flappy Bird if that tickles your fancy.

[Thanks to Gregg for the tip!]

World’s Smallest LED Cube – Again

January 30, 2017 by 36 Comments

There’s a new challenger on the block for the title of the “Worlds Smallest 4x4x4 RGB LED Cube“. At 13x13x36 mm, [nqtronix]’s Cube Pendant is significantly smaller than [HariFun’s] version, which measures in at about 17x17x17 mm just for the cube, plus the external electronics. It took about a year for [nqtronix] to claim this spot, and from reading the comments section, it seems [HariFun] isn’t complaining. The Cube Pendant is small enough to be used as a key fob, and [nqtronix] has managed to really cram a lot of electronics in it.

The LED’s used are 0606 RGB’s which are 1.6mm square, although he did consider using 0404’s before scrubbing the idea. There’s many ways of driving 192 IO’s, but in this case, Charlieplexing seemed like the best solution, requiring 16 IO’s. Unlike [HariFun]’s build, this one is fully integrated, with micro-controller, battery and everything else wrapped up in a case made entirely from PCB — inspired by [Voja Antonic]’s FR4 enclosure technique, and the LED array is embedded in clear resin.

Continue reading “World’s Smallest LED Cube – Again” →

A Terahertz Modulator

January 29, 2017 by 14 Comments

We’re all used to the changes in the properties of radio frequency systems as the frequency increases and the wavelength becomes shorter. The difference between the way an FM radio and a WiFi adapter behave with respect to their environments, for instance. But these are relatively low frequencies in the scheme of electromagnetic radiation, as you will be aware with ever shorter wavelengths those properties change further until eventually we are not dealing with something we’d describe as radio, but infrared light.

Terahertz waves are the electromagnetic radiation that lies in that area between radio frequencies and infra-red light. You might expect that since science has delivered so many breakthroughs in both radio and IR, we’d have mastered them, but so far very few devices capable of working at these wavelengths have been developed.

A Nature paper from a group at Tufts University holds the promise of harnessing terahertz waves for applications such as data transfer, for they have developed the first terahertz modulator. It takes the form of a section of slot waveguide between two conductors on a substrate, interrupted by what they describe as a two-dimensional electron gas. This is a very thin layer of electron concentration in an InGaAs region of a semiconductor sandwich that can be created or dissipated by electrical stimulus. This creation and removal of the electron layer has the effect of interrupting the flow of terahertz waves in the waveguide, making a functional modulator.

Continue reading “A Terahertz Modulator” →

Annoy Your Neighbors With MIDI Musical Siren

January 29, 2017 by 33 Comments

[Yannick], aka [Gigawipf] brings us this (mostly) musical delicacy: a 3D-printed siren that’s driven by a brushless quadcopter motor, and capable of playing (mostly) any music that you’ve got the MIDI score for. This is a fantastic quickie project for any of you out there with a busted quad, or even some spare parts, and a 3D printer. Despite the apparent level of difficulty, this would actually be a great quickie weekend build.

Continue reading “Annoy Your Neighbors With MIDI Musical Siren” →

Hackaday Links Column Banner

Hackaday Links: January 29, 2017

January 29, 2017 by 27 Comments

A 3D printer and laser cutter were cited as cause in two deaths. A couple (and two cats) were found dead in their apartment this week. The cause of death was carbon monoxide poisoning. Police and the gas company investigated the residence and found no other source of carbon monoxide besides a 3D printer and a laser cutter. Be sure to check out the people who know more about these deaths than the people who actually investigated these deaths in the comments below. In the mean time, get a CO detector. It’s nasty stuff.

At CES last this month, Lulzbot unleashed the MOARstruder. It’s an extruder with a massive, massive, 1.2mm nozzle. [James] from xrobots dot co dot uk just got his hands on the MOARstruder and the initial results are pretty cool. With a 1.2mm nozzle, you can print big parts fast (helpful for [James]’ massive builds), and the parts are stronger. Check out the video for a great hammer vs. printed part test.

We knew this would happen eventually. Pi Blades. Element14 is now offering ‘breakout boards but not quite’ for the full-size Raspberry Pis and Pi HATs. The idea of this product is to package clusters of Pis into an easy-to-use form factor. The Bitscope Blade Quattro, for example, provides power to four Pis. In other news, I own 20% of the world’s supply of vertical SODIMM sockets.

Arbitrary Code Execution On The Nintendo 64. A bit of background is required before going into this. Pokemon Stadium is a game for the N64. It used a Transfer Pak to read the save game data on Pokemon Game Boy cartridges to battle, trade, and organize Pokemon. Additionally, the Pokemon Tower in Pokemon Stadium allows players to play first-gen Game Boy Pokemon games from within an N64 – sort of like the SNES Super Game Boy. By using two Game Boy Pokemon games and two Transfer Paks, arbitrary code can be executed on the N64. Video demo right here. This is really cool, and the next obvious step is a ‘bootloader’ of sorts to allow arbitrary code downloading from controller button presses.

The Travelling Hacker Box is on the move! The original plan for the Travelling Hacker Box was to visit home base for the 2016 Hackaday SuperConference, then depart to foreign lands beginning with Canada, Greenland, Europe, Africa, Asia, Oceana, and the other America. After the SuperCon, the box was shipped out to its first recipient in Canada. The box came back. Something with customs. Now, the Travelling Hacker Box is on the move again. The plan is still the same, it’s just delayed a month or two. If you want to check out the future travels of the Travelling Hacker Box, here you go.

Light Rider: A Lightweight 3D Printed Electric Motorcycle!

January 29, 2017 by 43 Comments

It sounds like the name of a vehicle in some sci-fi tale, but that fiction is only a short leap from reality. Light Rider is, in fact, an electric motorcycle with a 3D printed frame that resembles an organic structure more than a machine.

Designed by the Airbus subsidiary [APWorks], the largely hollow frame was devised to minimize weight while maintaining its integrity and facilitating the integration of cables within the structure. The frame is printed by melting a sea aluminium alloy particles together into thousands of layers 30 microns thick. Overall, Light Rider’s frame weighs 30% less than similar bikes; its net weight — including motor — barely tips the scales at 35 kg. Its 6 kW motor is capable of propelling its rider to 45 km/h in three seconds with a top speed of 80 km/h, and a range of approximately 60 km — not too shabby for a prototype!

Continue reading “Light Rider: A Lightweight 3D Printed Electric Motorcycle!” →

EEPROM Hack To Fix Autodetection Issues

January 29, 2017 by 11 Comments

Autodetection of hardware was a major part of making computers more usable for the average user. The Amiga had AutoConfig on its Zorro bus, Microsoft developed Plug And Play, and Apple used NuBus, developed by MIT. It’s something we’ve come to take for granted in the modern age, but it doesn’t always work correctly. [Evan] ran into just this problem with a video capture card that wouldn’t autodetect properly under Linux.

The video capture card consisted of four PCI capture cards with four inputs each, wired through a PCI to PCI-E bus chip for a total of sixteen inputs. Finding the cause of the problem wasn’t too difficult – the driver was detecting the card as a different model with eight inputs, instead of the sixteen inputs actually present on the card. The driver detects the device plugged in by a unique identifier reported by the card. The code on the card was identical to the code for a different model of card with different hardware, causing the issue.

As a quick test, [Evan] tried fudging the driver selection, forcing the use of a driver for a sixteen-input model. This was successful – all sixteen inputs could now be used. But it wasn’t a portable solution, and [Evan] would have to remember this hack every time the card needed to be reinstalled or moved to a different computer.

Looking further at the hardware, [Evan] discovered the card had four 24c02 EEPROM chips on board – one for each PCI card on board. Dumping the contents, they recognised the unique identifier the driver was using to determine the card’s model. It was then a simple job to change this value to one that corresponded with a sixteen-input card to enable functional autodetection by burning a new value to the EEPROM. [Evan] then published the findings to the LinuxTVWiki page. Continue reading “EEPROM Hack To Fix Autodetection Issues” →