[hatari-devel] New patch for crossbar : ultimate arena wanted

[Nicolas Pomarède]

Le 01/06/2011 21:51, Eero Tamminen a écrit :

> Btw. Nicolas, when I looked how the STE DMA code handles it:
> ---- ioMemTabSTE.c --------
>          { 0xff8900, SIZE_WORD, DmaSnd_SoundControl_ReadWord,
> DmaSnd_SoundControl_WriteWord },   /* DMA sound control */
> ---- dmaSnd.c --------
> void DmaSnd_SoundControl_ReadWord(void)
> {
>          IoMem_WriteWord(0xff8900, nDmaSoundControl);
> ...
> void DmaSnd_SoundControl_WriteWord(void)
> {
> ...
>          nNewSndCtrl = IoMem_ReadWord(0xff8900)&  3;
> ---------
>
> While I assume this works fine, according to Compedium $ff8900 byte of this
> word is Falcon only while $ff8901 byte is used by everything else except
> STF, so the code above seems a bit misleading?

Well, Atari's doc for STE really defines this register as a word at 
$ff8900, with only 2 bits used, so I think this way of reading/writing 
SoundControl is the good one.


Nicolas