Re: [hatari-devel] Improved timings for the FDC emulation

["Roger Burrows" <rfburrows@xxxxxxxxx>]

On 23 Nov 2013 at 23:53, Nicolas Pomarède wrote:
> On 23/11/2013 23:29, David Savinkoff wrote:
> >
> > I also noticed that Hatari/EmuTOS always shows Drive B:
> > when both drives are disabled now.
>
> Isn't that the same on a real STF ? If I start mine with drive B turned
> off, drive A and B icons are displayed nonetheless on the desktop.
> What matters is the content of 0x4c2.l once GEM is up as it contains the
> bitmask for the detected drives ; do you have 0 or 1 or 3 in this case ?
>
IIRC, EmuTOS only shows floppy drives that physically exist (it doesn't support
TOS's "virtual floppy" concept).  So I expect that EmuTOS believes that both
drives are really there.

> But I don't know how emutos is checking if a drive is on or off, if I
> recall correctly there were some discussions lately about this and it
> used a slightly different sequence of FDC commands than a real TOS.
>
I can post a summary here of how EmuTOS does drive detection, if that would be
helpful.  If there's an error in the logic, I'll certainly fix it.

Roger