Atari 800 EPROM cartridge hack

atari-800-eeprom-hack

[Chris Osborn] had an old Atari 800 collecting dust and decided to pull it out and get to work. The problem is that it’s seen some rough storage conditions over the years including what appears to be moisture damage. He’s read about a cartridge called SALT II which can run automatic diagnostics. Getting your hands on that original hardware can be almost impossible, but if he had a flashable cartridge he could just download an image. So he bought the cheapest cartridge he could find and modified it to use an EPROM.

When he cracked open his new purchase he was greeted with the what you see on the left. It’s a PCB with the edge connector and two 24-pin sockets. These are designed to take 4k ROMs. He dropped in an EPROM of the same size but the pin-out doesn’t match what the board layout had in mind. After following the traces he found that it is pretty much an exact match for an Intel 2764 chip. The one problem being that the chip has 28-pins, four too many for the footprint. The interesting thing is that the larger footprint (compared to the 2732) uses all the same pins, simply adding to the top and moving the power pins. A small amount of jumper wire soldering and [Chris] is in business.

Gaming system inside an Atari joystick

gaming-system-inside-an-atari-controller

This original Atari controller is pretty small (take a look at that RCA cable for a sense of scale). Despite it’s size, [Kyle Brinkerhoff] managed to fit a complete gaming system inside the controller. This Pocket Sized Atari is a follow-up to another project he did called ArduPong which let him play Pong using a joystick and an Arduino. This rendition takes the external project box from that build and moves everything into one tight little package.

In the video after the break [Kyle] gives us a tour of the internals. The Arduino board he went with is an Ardweeny which is no bigger than the ATmega328 footprint so it can be easily mounted off to one side. The joystick internals have been replaced with the analog stick module from a PlayStation controller. That is where the button came from as well. Just connect this to a 9V battery and the composite video input of a TV and you’re ready to do some gaming!

Now if you just want that retro look for your Xbox Live games check out this Xbox 360 controller in an Atari joystick.

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Using a watch to control Ms. Pacman

Recently, [Alan] broke out the ‘ol Atari 2600 to relive his childhood with a bit of Yar’s Revenge and Adventure, but after looking at his new TI EZ430 Chronos watch, he figured he could add a bit of motion control from this classic game system. He used the accelerometer in this watch to play Ms. Pacman by tilting his wrist, an awesome build that really shows off the power of his new wrist worn device.

The watch is running stock firmware and communicates to a PC via an RF module attached to his computer’s USB port. The accelerometer data is fed into a VB.net app to convert the movements of the wrist into up, down, left, and right commands. These commands are then sent out over a serial port to an Arduino to translate those commands into something the Atari joystick port can understand.

Sure, it may be a roundabout way of playing Ms. Pacman, but considering the TI Chronos has been used for very serious work such as stopping SIDS and helping out soccer referees, we’re happy to see a more frivolous application for this neat watch.

You can check out [Alan]‘s video after the break, or get the VB and Arduino source here and here.

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Building your own atari cartridges

Have you ever wanted to create your own atari games from scratch? Thanks to the Grand Idea Studio, you can download the files to make your own cartridge PCBs. There isn’t a ton of information here, as this is an old project that isn’t being supported anymore. However, you can download the instructions, schematics, and gerber files for carts that work in the 3 main models of the atari 2600. As [Tyler] over at Adafruit points out, you could easily 3d print your own shell as well.

Putting an Atari POKEY in your pocket

The Atari POKEY served as the main I/O chip on the venerable Atari 400/800 and XL/XE 8-bit computers. While a chip designed to get voltages from game paddles and scanning a matrix of keyboard switches wouldn’t normally be remembered 30 years later, the POKEY had another function: generating very, very distinctive music and sound effects for those old Atari games. [Markus Gritsch] wanted a portable version of the POKEY, so he emulated one on a modern microcontroller. Now he’s able to take those old Atari chiptunes where ever he goes.

The build uses the Another Slight Atari Player by emulating a 6502 and POKEY chip inside [Markus]‘ PIC32MX-based microcontroller. There’s not much physical hardware [Markus] had to deal with – the board is built on a QFP proto board [Markus] picked up with a few buttons and a jack added for some simple I/O.

This isn’t [Markus]‘s first attempt at portabalizing chiptunes – last year, we saw a truly awesome portable SID player that used the same PIC32 microcontroller and an emulated 6502. Between the Atari SAP Music Archive and the High Voltage SID Collection, [Markus] has more than enough chiptunes for days of listening pleasure.

Using an NES controller with an Atari 2600

Instructibles user [Danjovic] managed to get his hands on an Atari 2600, but all the joysticks were damaged beyond repair. Instead of building an atari joystick from scratch, he looked to a slightly newer generation of gaming and decided to us an NES controller instead. This was done fairly easily with the aide of an Arduino.

This seems like a nice easy mod that could breathe a little new life into some old games, but we just can’t imagine playing without that original joystick!

Playing chiptunes with a YM2149 and optimizing an Arduino

[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.

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