Re: [hatari-devel] TOS v4 / TT-RAM issue with floppy images

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 27/11/2017 à 10:27, Thorsten Otto a écrit :
> On Montag, 27. November 2017 10:19:30 CET Nicolas Pomarède wrote:
> > Wasn't there some kind of cookie that needed to be created so FDC would
> > first tranfer data using DMA to normal memory, then cpu would copy these
> > data to TT RAM ?
>
> The _FRB cookie, yes. Its value is a pointer to an 64K buffer. But maybe
> original TOS 4.04 does not check this, because a real Falcon does not have TT-
> RAM.

That's what I was thinking too. In the case of the CT60 card, there was 
a also a TOS replacement with lots of patches to extend the capability 
of the falcon to 32 bit space in addition to supporting a 68060

As you say, real falcon doesn't support TT RAM, so maybe an extra 
program would be needed at boot to intercept TOS accesses and ensure FDC 
data are transferred between RAM and TT RAM.