# Atari Coldfire Project

The Atari Coldfire Project (ACP) is a volunteer project that has created a modern Atari ST computer clone called the FireBee.

## Reason for the project

The 16- and 32-bit Atari ST microcomputers were a popular line of home computers in the 1980s and the first half of the 1990s, to which the mostly- or semi-compatible Atari TT and Falcon computers were added in the early nineties. However, in 1993, Atari largely withdrew from the computer market, and in 1995-1996, when Atari merged with JTS, the company withdrew completely and dropped all of its support for the platform. The systems Atari had built got increasingly left behind as newer and faster systems came out for other platforms. A hard core of dedicated users still wanted more processing power to develop more advanced applications for their preferred platform's Atari TOS operating system. This demand paved the way for a number of "clone" machines, such as the 68040-based Milan and the 68060-based Hades, both of which were considerably more powerful than even the 68030-based TT and Falcon, as well as the 68000-based ST/STe computers. These machines supported ISA and PCI buses, which made use of network and graphics cards designed for the PC possible (something no original Atari machines could do). The machines also supported tower cases, making it possible to use internal CD drives.
A new clone named Phenix never made it to market in final form. However, the powerful rev. 6 68060 CPU it was to use did make it into a new accelerator board for the Falcon, the CT60/CT63 series, which meant that, for the first time, the Atari platform had a CPU rated at over 100 MHz. The use of a high-speed bus and PC133 RAM also accounted for a big performance improvement and significantly increased the Falcon's on-board memory limit from 14 MiB to 512 MiB with a CT60.
These systems were not mass-produced and became hard to find. While the CT60/CT63 needed a Falcon "donor" system, and was still not as powerful as the ACP system, the ACP's FireBee used a completely new design, moving away from 68K CPUs to the newer ColdFire class, more powerful than even the fastest 68K chips while still having a largely similar (but not completely compatible) instruction set. It also allowed for the integration of many I/O ports that hitherto were only available through extensive hardware modification on the Atari platform.

## Specifications

The specifications for the ACP have changed considerably over time, in response to advancing technology and price considerations. However, it seems the following will be in the final design according to former Atari Coldfire Project homepage:
* Processor: Coldfire MCF5474, 264 MHz, 400 MIPS
* RAM: DDR, 512 MB Main- + 128 MB Video- and Special-RAM on Board, Speed: 1 Gbit/s
* Flash: 8 MB onboard for operating systems
* Atari compatible interface ports:
** TT/Falcon-IDE,
** ST/TT-Floppy
** TT-SCSI (but faster)
** ACSI
** ROM-Port: 2×2 mm Connector
** Printer Port, parallel
** ST/TT-serial
** MIDI
** ST-Sound, YM2149 over AC'97
** ST/TT/Falcon-Video
** Atari-Keyboard with Mouse
* Other Ports:
** Ethernet 10/100, 1 Port
** USB 2.0 Host (ISP1563), 5 Ports
** Compact-Flash, 1 Port
** SD-Card, 1 Port
** AC'97 Stereo Codec with DMA-Sound Output and 48 kHz Sampling Input
** Sound_Connectors: LineIn, LineOut, Mic (Mono), DVD/CD internal
** New Video Modes about 2 megapixels, true color
** PS2 Mouse/Keyboard Port
* Battery Powered (if desired)
* PCI 33 MHz direct Edge for passive backplane
* Power controller with real time clock, PIC18F4520
* Extension socket: 60Pol (DSPI 33 megabaud, serial sync or async about 33 megabaud, 26 bit I/O about 133 MHz, I$^2$C-Bus)
* Asynchronous 512 KB static RAM for DSP or similar already planned extensions in the future: Falcon DSP in the FPGA
* Format: Card 90 × 260 × 20 mm
* Power consumption of the complete board: 3 to 5 watts

## Operating systems

On the 8 MB ROM, FireBee devices have the following pre-installed software:
* BaS (BasicSystem)
* FPGA config
* FireTOS
* EmuTOS
There's a ready to use FreeMiNT and GUI environment setup with applications ported to work on ColdFire which can be ordered on CompactFlash card with the device.
μClinux has also been ported to FireBee.

## Compatibility

There are different strategies for dealing with the differences in ColdFire and 68K instruction set and opcodes:
* FireTOS includes 68K emulation based on an illegal instruction exception handler and CF68KLib
* 68Kemu program (based on Musashi 68k emulator) can be used to run 68K programs with EmuTOS
* Most of the operating system and basic desktop software has been ported and built for ColdFire and rest is able to run with emulation
* Several commercial and shareware Atari SW packages have also either been ported to ColdFire or open sourced so that they could be ported to FireBee
FireBee FPGA doesn't yet provide DSP functionality which means that any Atari Falcon specific programs requiring DSP won't run. Many Falcon games and demos use it to play background music.

## Development tool support

* GCC, VBCC and (Pure C compatible) AHCC C-compilers and their libraries have fully working ColdFire support
* Digger disassembler supports ColdFire
* RSC-editors like ResourceMaster work on Firebee
* GFA Basic has been modified to support FireTOS
* SDL library and its (Atari specific) LDG dependency are ported to ColdFire/FireBee