Re: [hatari-devel] Regression in 2.0.0 RC1

[Anders Eriksson <ae@xxxxxx>]

On Fri, 28 Oct 2016, Nicolas Pomarède wrote:

> Apart from that, here're some things that could be measured on STE :
>
> - set start=end, start dma sound with repeat off : does dma turns off 
> immediately or at the end of the next video line where FIFO would be filled ?
> Do we get the "end of frame" timer A interrupt in that case ?
> I guess dma sound counter and bit 0 of ff8901 are updated at the end of each 
> line, when display enabled is set to off and shifter displays border color.

Hello,

I tested this; set start and end the same, and start replay without loop. 
I've also initialized Timer A in event mode to invert background colour if 
it happens. I set event to 1 so it will interrupt after the first loop.

Results:

- Hatari 2: noise played, no inverted background
- STe: silent, no inverted background


> - if start=end and we start dma sound with repeat on, do we also get an 
> immediate end of frame timer A interrupt, just before dma address goes beyond 
> end address ? As the end condition seems to not be correctly checked in that 
> case, maybe the end of frame bit in the MFP is not available either and we 
> would not get an input on timer A in event count mode ?

So the same program as above, but with loop.

- Hatari 2: noise played, no inverted background
- STe: a tiny click then silence, no inverted background

So it would seem with repeat the STe does play a little bit of data before 
shutting off.

Maybe I did some mistake in the code, here it is for both tests:
http://ae.dhs.nu/tmp/hdma2.zip

--
Anders Eriksson
ae@xxxxxx     http://www.dhs.nu/
ae@xxxxxxxxx  http://www.atari.org/