Retrocomputing

6502

Apple2FPGA


6502: igniting the digital revolution

The 6502 was pure magic out of transistors. The creators of this microchip are truly digital heroes that achieved the unthinkable: creating a low-cost microprocessor in 1975 that shaped the electronic industry. This device was used in legendary machines, such as Atari VCS 2600, Apple II, Commodore 64, Nintendo Famicon, etc. In April 2017, I had the opportunity to pay homage to this wonderful tiny microprocessor by means of an (imperfect) presentation. I deeply enjoyed the process of connecting the numerous dots that outline a fascinating and unique story. Indeed, a key element to understand the creation of the PC and the birth of the videogame industry.

Links

6502.org: The 6502 microprocessor resource

The Visual 6502 project: Wanna see the transistor activity while executing assembly code? This is the place

Apple][ history website: The reference place to learn about the Apple ][

Commodore: a company on the edge: Amazing book about the first steps of Commodore Bussiness Machines into computing. The inception of the 6502 chip is beautifully described.

Talks

El microprocesador 6502 y su impacto en la revolución digital [slides][video] , RetroMadrid, April 2017 (in Spanish)


Apple2FPGA

The Apple2FPGA is a project by Stephen A. Edwards, Professor at Columbia University. He succesfully implemented the computer Apple][-plus on Altera's DE2 FPGA board. This implementation enables the hardware emulation of this famous computer, that is, inside the FPGA there are replicas of the different microchips used in the original system. It even has floppy-disk drive emulation through an SD card! Version 1.2 from Edwards's website include an update disk controller compatible with SD cards v.2.x designed by Michael Stempin. I thank both for their help migrating the project.

This project got my attention since I have a DE2-115 board in our lab, a more powerful version of the DE2 board, and I thought it would be great to modify the project to make compatible with our board. So, basically I changed the pinout of the original project to fit that of the DE2-115 board.

Download

Apple2FPGA for DE2-115, Altera Quartus II v13.0 project

Links

Apple2FPGA project: with nice photos, comments on FPGA power consumption and implementations for the DE2 board (v1.0 and v1.2)

Sophistication & Simplicity: The Life & Times of the Apple II Computer: a great book by Steven Weyhrich on the history of Apple][. The first steps to the Apple2 creation are a must read

Apple][ history website: The reference place to learn about the Apple ][

Commodore: a company on the edge: not about Apple ][ but a great and enjoyable reference about the conception of the MOS technology 6502 microprocessor (the brain of the Apple ][ and many other great machines)

Talks

Implementación de microordenadores con dispositivos FPGA: Apple][ en un chip , RetroMadrid Days, June 2015 (in Spanish)
Arqueología digital: Cómo reconstruir un Apple II con tecnología moderna, Semana de la Ciencia 2016, Universidad San Pablo CEU, November 2015
Diseño de ordenadores clásicos con FPGAs (slides) (YouTube), RetroParla 6.0, Parla, January 2016 (in Spanish)