Re: Virtual Memory (Was Re: Kernel 1.14.7 available)

[Johan Klockars <rand@cd.chalmers.se>]

> > Tha Falcon VDI could[1] be able to work without the blitter as long as you
> > do not use more than 16 colors.

Why would that be so?
If anything, I'd expect the blitter not to be used in true colour mode, but
eight bit should be handled the same as any other bitplane mode.

> > The problem might be to turn off the blitter: I am not sure if the XBIOS/VDI

There has never been a way to 'turn off' the blitter, only to stop the VDI
(and LineA) from using it. Since no Falcon was ever produced without a
blitter, I guess it made sense not to include the 'blitter emulation' code.

> > functions which cause the problems use a trap or if they instead use direct
> > subroutine calls in the ROM, which would be 'difficult' to patch. At least

The AES always TRAPs to the VDI for output, but the VDI itself has little
reason to do so. The standard VDI probably uses LineA (why else would it be
there?), however, so it might be enough to patch that.

> disabled), but haven't been able to patch the VDI. And if there's
> something Doug Little can't do with a Falcon, it's not *possible* to
> do with a Falcon ;-)

I would tend to agree.  ;-)

> > If this is true, VM would really depend von NVDI or similar.
> 
> This isn't really a problem, there's not many left that still use the
> original VDI.

I'd be very surprised if the majority of people have _bought_ a replacement
VDI (that would've made for a _huge_ profit margin on NVDI) and it would in
any case be a lot better, IMO, if MiNT could be used without relying on
non-free software.

Anyway, fVDI will (hopefully) soon be really usable for screen output and
the blitter will then no longer be a problem.

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