Re: [hatari-devel] 68040/68060, external FPU?

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

Hi,

On 6.7.2025 18.13, Uwe Seimet wrote:
> I noticed that Hatari accepts configuring an external FPU when using a
> 68040/68060 processor. As far as I know neither 68040 nor 68060 support an
> external FPU.

On quick googling I didn't find any definitive statement on that, but it 
seems to be so.

> Wouldn't it be better to reject such a configuration?

Hatari cannot really reject it because there's no separate setting for 
enabling FPU for 040/060 and selecting FPU type for 030.

Because initial config values coming from config file, and user being 
able to give CLI options in any order, it would be bad to reject:
	--fpu internal --cpulevel 4
	--fpu 68882 --cpulevel 3
But accept:
	--cpulevel 4 --fpu internal
	--cpulevel 4 --fpu 68882
Depending what was in config file, or earlier in command line.

Changing config value for FPU type, once machine/CPU type is known, has 
issues too, but maybe it would make sense to output a warning about it.

What the warning says, would depend on whether WinUAE CPU core already 
ignores non-internal FPU setting for 040/060 though.  I haven't checked.

Nicolas?


	- Eero