ZX81 Project : A ZX81 remake

 

 

Here is my ZX81 project : a remake of the famous ZX81 computer, based on the original schematics.

Warning : It has not been tested yet : it should be done in a couple of weeks.

Have fun !

 Package

 

256-in-1 : 256 games cartridge for Atari 2600/7800

 

Version 07/05/2014

Few months ago, I finished a new cartridge for the Atari 2600/7800.

This piece of hardware can be seen as a huge cartridge, containing up to 256 (Atari 2600) games or homebrews. Originaly, this board was made just to show something to users during a retro-gaming day (AC 2014). Because I had only one month to do it before the show, I decided to do something very simple and cheap.

Usage and restrictions

• This cartridge can handle 2KB and 4KB rom images only (Not banked),
• Only Atari 2600 rom images are supported,
• The board can be plugged-in Atari 2600, Atari Jr and Atari 7800,
• User should select the rom image with the corresponding micro-switch position before power on.

Enjoy !

Buzz

Package
 

ArcadeUSB : Simple way to connect arcade buttons to USB Interface

 

 

Version : 2014-10-13

This arduino sketch has been developped for my bartop project.

Just few words about my it. It is not yet finished but it is composed mainly by :

• some wood,
• a PC,
• a LCD display,
• buttons and joysticks.

To manage the buttons, it is necessary to have an interface between buttons/joysticks and the PC in charge of the emulation. There are different solutions to do that.

• Reusing an existing keyboard. This is cheap but it is difficult to assign buttons to specific key because the matrix is not so simple,
• The other solution could be to buy a "ready-to-use" interface but I do not like this choice,
• The last one is to make the interface by yourself.

Instead of re-inventing the wheel, I have chosen the Teensy ([Web site|https://www.pjrc.com/teensy]) as a developpement board. It is arduino compatible but it manages the USB natively. Because I need to manage at least 30 different keys, I have decided to add an input-mutiplexing interface to the Teensy (See IExpender project).

To go back to the sketch, it is very simple. It has been developped with Arduino 1.0.5 IDE to target a Teensy 2.0. Buttons should be connected to the interface (IExpender) according to the mapping table (See code).

Then the interface has to be connected to the Teensy board, and of course the Teensy to the PC

Have fun !

Buzz

 Package

 

IExpender : Generic 4x 8bits input ports

 

Version 30/09/2014

When playing electronics with microcontrollers, you sometimes need to manage a lot of inputs (sensors or buttons).

Instead of using a bigger controller to have more IO ports, it is better or simpler to add extra components to it.

This piece of hardware, based on simple logic chips, uses 10 pins (8 bits for data and 2 bits for control) to manage 32 inputs.

In my case, I need this to connect 32 buttons to an arduino board.

Usage and restrictions

• 4 banks of 8 bits. Each bank handles 8 inputs,
• Bank number is selected with 2 control signals (signals A and B on 74LS138),
• The board can be extended to manage 64 inputs (4 other 74LS541 must be added)
  
  

Enjoy !

Buzz

 

Package 

Atari 7800 Multicart

 

Version: 30/09/2014

A long time ago, I have created a Multicart for the Colecovision.

Now, it is time to do the same for a very nice console : Atari 7800 console.

For the moment, only a prototype has been made and I am still debugging it. I will post the full package when all bugs are fixed.

Keep in touch !

Buzz

CPC - Y : How to connect 2 joysticks to an Amstrad

Version : 12-03-2013

This project is used to connect 2 joysticks to an Amstrad CPC464/664.

The original schematic comes from http://www.cpcwiki.eu/index.php

Do not hesitate to have a look at this website :  http://www.cpcwiki.eu/index.php

This single side PCB should be easy to make. Only 3 connectors and 14 small signals diodes.

Usage
Just plug-in your 2 joysticks and connect the board to the josytick port of your Amstrad.
That's it !

Enjoy !

Buzz

Package 

2MB SRAM Extension for AVNET SPARTAN Evaluation board

 

Version : 14/02/2013

Here is a new version of SRAM extension for the AVNET  Xilinx Spartan-3A Evaluation Kit (Réf : AES-SP3A-EVAL400G) .

All the necessary files to build your own are included into the attached file.

Have fun !

Buzz 

Package