The Amiga Coldfire V4 CPU Upgrade

A second attempt at developing a Coldfire processor upgrade to the Classic Amiga. There are also plans to develop a standalone AROS version. Unlike IAT Manufacturing's earlier effort, the upgrade is being developed using the later Coldfire v4 CPU. The attraction of the Coldfire CPU is evident. Unlike the expensive PowerPC processors of next generation Amigas, the Coldfire V4 162Mhz costs just £25. This would offer a significant performance increase in comparison to existing 68060 software, while opening the possibility for SDRam, Firewire, USB, Ethernet, & PCI expansion for Amigas that are not covered by existing expansion options.

Although the project faces an uphill battle (depending upon the amount of work required to patch the AmigaOS and produce prototype boards), the two-person team have already had an offer of support by an undisclosed company that may speed its development. In a project FAQ, Oliver indicates the A2000 will be the first Amiga to gain Coldfire support, followed (in order) by the A4000, A500, CD32, A600, CDTV, A1000, and possibly an A3000 version. An unusual list that is heavily influenced by the machines available for testing purposes and their individual architecture.

The Amiga Coldfire FAQ indicates that several stages will require completion before the hardware is ready for consumer use:

Stage 1 - "the first prototype will just have the Coldfire in it, No SDRam memory or expansion ports, Just the Coldfire. This will run much slower than the Coldfire is capable of as it will have to use the motherboards ram but it will give us a good idea of just how compatible the Coldfire is without the Motorola patch, A provision will probably be made on this prototype for a ROM so the patch can be loaded before the Kickstart."

Stage 2 - " If the Amiga fails (Due to Kickstart exceptions) then we will either have to compile the AROS source for the Coldfire or to start with just try different Kickstart revisions, We need to get the basics up and running on the Amiga before we can evolve the design, Workbench is unimportant, CLI is all we need, Even the library's on the workbench disk can be recompiled to the Coldfire as and when we need it."

Stage 3 - "After we have a platform to build off the next two things to add will be the SDRam / 72 Pin SIMM slots, This will give an instant speed increase and let us fit half a gig of ram onto the computer (Try doing that with a Cyberstorm PPC) and adding an expansion/diagnostic port. We intend to have a generic expansion port on each model of card so an upgrade for the A500 will fit an A4000T and work just as fast, This also helps us with diagnostics as it will have all the signals available, Giving us a window into what's going on."

Subsequent development - "The expansion port will latter carry upgrades such as Firewire, USB and ethernet ports and PCI (Maybe Zorro 3 on Amiga`s with no Zorro 3 slots) slots. (Some of these features may be built into cards where there is plenty of room like on the A2000 and A500, Even the A3000."

Is the Coldfire project a realistic development?

It is only natural that the majority of Amiga users will be cynical at *yet another* hardware upgrade for the Amiga. The last few years have produced dozens of abandoned efforts to produce a suitable upgrade. The current emphasis upon AmigaOS 4 and PPC leave little room for a Coldfire port. However, the Coldfire processor is a natural upgrade to the 68k - an argument that has convinced many Atari users. However, the AmigaOS offers its own unique problems. Like existing PowerPC boards, Amiga 68k will not benefit from a speed increase unless it accesses the new hardware (coldfire.library?) or emulates the Amiga processor. If the latter is the case, it will require access to the Amiga chipset in order to execute hardware-hitting software. The use of AROS removes this dependency, but may require a port of UAE for users to consider it a 'real' Amiga. Whatever the result, its development will be an education for its creators and the Amiga market.

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