Processor: 6502 (note: This is Atari's custom 6502 which can be halted to allow other devices to control the bus)

Speed: 1.79Mhz, drops to 1.19Mhz when the TIA or RIOT chips are accessed

RAM: 4K

ROM: built in 4K BIOS ROM, 32K Cartridge ROM space without bankswitching

Sound: TIA custom sound chip, same as the 2600

Graphics: MARIA custom graphics controller, 320x200 resolution with 256 colors.

I/O: Joystick and console switch IO handled byte 6532 RIOT and TIA

Ports: 2 Joystick ports, 1 Cartridge port, 1 expansion connector, Power in, RF output

7800 Software Guide - PDF, Plain Text

PAL DEV System - Converting a PAL 7800 into a dev system (by Graham.J.Percy)

Cartridge Pinouts - This file describes the pinout of the cartridge port and the function of each of the pins

Memory Map - This file describes the memory map of the 7800.

Video System - A description I wrote of how the 7800 video systems works.

Cartridge List - This is a list of the 7800 cartridges I have opened up and what type the cart is (normal, Pokey, Supercart, etc)

7800 EPROM conversion - This document was written by Bruce Tomlin and describes how to modify the 7800 so that the BIOS ROM can be replaced with an EPROM.

US4026555: Television display control apparatus

US4112422: Method and apparatus for generating moving objects on a video display screen

US3728480: TELEVISION GAMING AND TRAINING APPARATUS

US3659285: TELEVISION GAMING APPARATUS AND METHOD

7800 BIOS - This is the source code for the 7800 BIOS ROM. It was originally commented by Keith Henrickson, and further commented by myself.

7800 Sprite - This is my first working piece of 7800 code. It puts a simple sprite on the screen and allows you to move it left and right with the joystick.

Robotron - This is the beginnings of a dis-assembly of the7800 Robotron cartridge. It's still very preliminary but it's a start. If anyone has anything to contribute to it please e-mail me.

Food Fight - This is a partial dis-assembly of the 7800 Food Fight cartridge.

Various - You can find the original Atari source code for a number of 7800 games here.

MADS: MADS is a popular 6502 assembler for various Atari systems. You can find the english documetation here.

DASM.ZIP: This is an excellent 6502 cross assembler for MSDOS. It supports pretty much any feature you could want in an assembler including macros, and the ability to produce raw-binary files. Thanks to Bob Colbert for porting this assembler from the Amiga.

V7800 was an Atari 7800 emulator that I wrote a few years ago. After a couple releases I merged V7800 into the multi-system emulator MESS (see below).. I currently have no plans to continue this standalone version since it was just temporary until the MESS version was released. It's not perfect and it's a little slow, but it is playable. Due to copyright reasons, I cannot provide ROM images. PLEASE DO NOT E-mail me looking for ROM images. All messages looking for ROM images will be promptly deleted. I will do my best to answer all other e-mails.

7800 ROM images can be found at: http://www.atariage.com

What's new in V0.12:

- now shuts down properly when started with -nosound
- Fixed VBLANK timing. Foodfight now works.
- Added support for 48K carts
- Added pause button
- Fixed holey DMA support. Lucasfilm logo is now better
- Replaced 6502 CPU core with Neil Bradley's ASM 6502 core. (Increased speed, and accuracy)
- Fixed handling of fire buttons.
- Implemented Debugger. (Only available in debug version).

Click here to download V7800 V0.12.

Web Site: https://www.mamedev.org/
Author: Various
Platform: Windows, *nix, Mac
Accuracy: Good