[Oryx] grew up with the bleeps and bloops of an Atari ST, so it comes as no surprise he would want to relish in his nostalgia by playing with the YM2149 sound generator he recently picked up on eBay. Like most of us, [Oryx] went to his old standby, the Arduino, when it came to connect this bare chip to his computer. The first circuit didn’t work, so after a lot of poking around the firmware, [Oryx] discovered the benefits of hand-optimizing software.
There are a lot of sound files available for the YM2149 floating around on the Internet. These files are just dumps of the 16 registers at 50Hz, so it’s very easy to send these from a computer to an Arduino over a serial connection. Unfortunately, when [Oryx] got his breadboard set up nothing happened. After breaking out the ‘scope, he discovered the Arduino was switching pins 100 times slower than the YM2149 data sheet called for.
[Oryx] remembered seeing a great blog post going over the speed at which the digitalWrite() function changes pin states. We’ve seen this before, and the fastest way to change pin states on the Arduino is with the ugly bitwise manipulation. After changing a few lines of code, [Oryx] was switching two pins nearly simultaneously.
Now that the YM2149 chip is working correctly, [Oryx] is planning to make a MIDI synth out of his project. You can get an idea of how that will sound with the demo video he put up after the break.
Continue reading “Playing chiptunes with a YM2149 and optimizing an Arduino”
[Dablio] sent in an awesome console mod he made. It may just be the smallest Atari 2600 ever (Portuguese, here’s the Google translation).
The build began with a Dynacom MegaBoy, from the same company that put out many less-than-legal 2600 clones. The MegaBoy PCB is an exercise in parsimony consisting of only a single IC, a crystal, and some resistors and caps. [Dablio] made a new PCB board based on the schematic he reverse engineered and this thing is tiny. It’s much smaller than even the smallest [Ben Heck] 2600 console build.
[Dablio] now needed a case for his new console. He had originally planned to mount the whole thing in an Atari controller like this commercial product. Serendipity intervened and he realized the entire system (sans cartridge port) fit inside a plastic tube of m&m minis.
Currently, [Dablio] has two ports on his ‘Atari tube of m&ms’ – the largest is the cartridge slot, and a small VGA port sits in the lid of the tube. This VGA port carries the power supply, controller, sound and video signals to and from the console.
[Dablio] sent in a bunch of pictures of his build which are in a gallery after the break. Now for the million-dollar question: anybody know where to buy one of these Dynacom MegaBoys?
Continue reading “The teensiest Atari 2600 ever”
As a kid, [Boisy] cut his teeth on the TRS-80 Color Computer. It was a wonderful machine for its day, featuring a relatively powerful Motorola 6809 CPU. Although his CoCo was theoretically more powerful than its Commodore and Apple contemporaries, the graphics and sound capabilities of [Boisy]’s first love paled in comparison to his friends 6502-based machines. A little jealously and thirty years go a long way, because now [Boisy] is adding a 6809 microprocessor to the 6502-based machines Atari put out.
[Boisy]’s goal for his Liber809 project was simple: Put a 6809 CPU in an Atari XEGS and get NitrOS-9, the Unix-like OS for the TRS-80 CoCo running on his Frankenputer. After a few months of work, [Boisy] completed his goal and more so: the Liber809 also works on the Atari 1200XL.
To put [Boisy]’s work in perspective, it’s like he took a Macintosh from 1993 and made it run on an Intel 486. While that’s not a terribly accurate analogy, we hope our readers will understand the fortitude needed to make a computer run on a completely different processor.
After the break, you can check out a neat demo app written by [SLOR] from the AtariAge forums showcasing a 6809 running in a machine designed for a 6502. Awesome work for all involved
Continue reading “Giving an old Atari computer a much needed upgrade”
So do you have an Atari 2600 laying around collecting dust? Perhaps you’d like to have a musical instrument to take up the time that you would spend playing video games if you had a modern console. Well, look no further than the GATARI 2600!
[cTrix] made this device with a custom EPROM chip plugged in as a cartridge. Although details of the build are somewhat vague, this custom chip allows music to be written for the device. Everything is controlled with a joystick that tells the GATARI to generate the desired track. From this basic track, the sound is modified using three pedals including an equalizer, a flange pedal, and a hold pedal.
Check out the video after the break for a brief explanation of how it was built. Skip to 1:05 if you’d rather just see it in action at [Blipfest] in Japan!
If you’d rather listen to music rather than playing it, why not build your own snap together boombox instead!
Continue reading “The GATARI “2600” Musical Instrument”
We don’t know why, but the Atari Jaguar is getting a lot of attention this week. [10P6] just came up with this Jaguar/CD combo that reminds us what Atari could have come up with in 1993.
The build itself is relatively simple once you get past [kevincal]’s ‘April Fools’ type joke he played on the Atari Age forum. [10P6] took a regular Jaguar CD drive and cut a hole into a Jaguar case. The whole case mod took less than a three hours, but [10P6] gives us a lot of commentary into what Atari could and/or should have built in 1993.
[10P6] suggests this type of Jaguar would have saved Atari money if the CD drive was stock on the base unit and released at a slightly increased price. This would cut out the cost of the cart slots and reduced the amount of plastic in manufacturing. [10P6] also talks about how Atari engineers could have dropped the 68000 coprocessor with an increase in the system clock. We’re not quite fond of that idea (ask us about our tattoo), but the logic does make sense.
Of course, this build comes on the heels of the Jaguar Portable we saw a few days ago. Honestly, we have no idea what’s going on with the Jaguar build.
There’s nothing wrong with portable NESs, Super Nintendos, N64, or even a portable Sega CD. What about a portable version the oft-maligned Atari Jaguar, though? [Evil Nod] pulled it off, and it looks great.
The build is fairly standard for a portable console. A PS1 screen is used for the display, and a cut up and re-wired controller provides the input. From what we see on the build log, moving the 104-pin cartridge slot onto ribbon cables was an exercise in patience. The case is absolutely phenomenal with a textured finish we would expect to see on an early 90s console. Of course, [Nod] kept the numeric keypad; there was space left over anyway.
We can’t rag on the Jaguar or [Nod]’s build. It’s a great execution and there’s an impressive library of games that include Worms, Rayman, Doom, and Myst. Still, we wonder what the build would look like with the Jaguar CD-ROM attached.
A few years ago, [Richard] pulled a crushed camcorder out of a junk box at a hamfest. After pulling the half-inch CRT out of the viewfinder, he needed to find a project. [Richard] ended up building the second tiniest game of Tetris we’ve ever seen.
After futzing around with the CRT, [Richard] discovered that one of the pins would accept an NTSC input. He also found a similar project that used a dime-sized CRT to play Tetris. With ready to go code, [Richard] started assembling his project into a handsome wooden box.
There are two PCBs for the build – a CRT driver circuit, and a small custom board that handles the game and controller code. The circuit for the game board was found on this site, but the featured boards there were too large for the project. A stripped-down board was fabricated by BatchPCB and put into the box.
There aren’t any controls on the console itself, for that a standard DB-9 connector was installed so a vintage Atari joystick could be used. For a more ergonomic Tetris experience, a Sega Genesis controller could be used. For something that looks like it comes out a steampunk laboratory, playing Tetris is a bit unexpected. Check out the demo video of the screen at 20x magnification after the break.
Continue reading “Building the second tiniest Tetris”