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Re: [MiNT] EmuTOS for ColdFire



I know that, but is a CodFire between a 68000 and 68010? That is what I don´t understand.

The ColdFire family must not be seen like the successor of the 680x0 family, but like some kind of cousin.

According to current specs, the new ACP computer will use the MCF5474 processor. It belongs to the ColdFire V4e family.
The overview and full documentation is available on Freescale's website :
http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MCF547X&nodeId=0162468rH3YTLC00M93426

Basically, the MCF5474 ColdFire processor has the following features:

- Assembler instruction set is nearly the same as in the 68030, but some instructions and addressing modes have been removed (such as ROL, etc.). This is because nowadays most programs are written in high-level languages, and such instructions are rarely (or never) generated by them. So the hardware can be simpler, cheaper and faster.

- Frequency 266 MHz, 410 MIPS. Some benchmarks of different CPU are available on this page :
http://en.wikipedia.org/wiki/Million_instructions_per_second#Million_instructions_per_second
So for full native ColdFire software, we can expect a speed 410 times better than on the ST, or 75 times the speed of a Falcon. Beware at the numbers, this is rough estimation, a lot of parameters like the usage of coprocessors can change a lot the speed ratios.

- MMU, FPU, and new eMAC unit, for DSP-like instructions

- Additional peripherals built directly inside the processor chip !
Ethernet controler, serial ports, PCI bus...


So the ColdFire is the modern processor which is the closest to the original Atari architecture, so it is the best choice for starrting porting TOS to something other than 680x0.

--
Vincent Rivière