Re: [hatari-devel] TT mono mode Timer-C problem

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

Hi,

On perjantai 16 joulukuu 2011, Roger Burrows wrote:
> I was testing EmuTOS using TT mono mode (TT High), and had problems
> opening a drive window by double-clicking on the desktop icon.

Yes, it seems to be about impossible without using Hatari's
"middle click emulates double-click" thing.


> After a
> bit of work, I discovered that the 200Hz (5 msec) system timer is
> actually running at about 400Hz, which (among other things), speeds up
> the timer interrupt at etv_timer, and causes double-clicks to seem twice
> as slow as they really are.
> 
> The attached program (compiled under Lattice C on a real TT) uses the
> system ticks value in low memory to count off seconds and display them. 
> If you run this in TT mono mode, the seconds go by at about twice the
> normal rate.  The program also uses a crude loop counter to see if there
> is any significant variability in the time between clock pulses (I
> wondered if perhaps two clock pulses were being signalled every 5msec),
> but there doesn't seem to be.

Are the counts supposed to differ between TT color and mono resolutions?

For me they are same for both (4x times larger than for ST and 2x larger
than for Falcon).


> This problem occurs with either EmuTOS or TOS 3.06, but ONLY in TT mono
> mode. It does not occur if the screen mode is set to RGB.


 	- Eero