mfro wrote:If memory doesn't fool me, I think I remember some docs saying writing low order bits would clear high order bits?
Steven Seagal wrote:I don't have the answer, but when I tested it in Steem (clearing high bytes at writes to lower bytes), the sound was obviously wrong, so Steem doesn't check that at all.
ijor wrote:Sound? Please note I am talking about ST DMA, floppy and ACSI, not STE sound DMA.
npomarede wrote:On STE, do you think the same rule applies when writing to video counter ?
Steven Seagal wrote:STE documentation by The Paranoid:
! The DMA-Soundsystem expects you to write the high-byte of the Start- and
Endaddress first. Even though this serves no purpose at all, writing the
highbyte clears the others. Hence it must be written first.
Engineering Hardware Specification Atari Corp: 841017B
The DMA Base Address and Counter Register must be loaded in low, mid, high order.
Can we say this restriction is due to Atari using cheap components?
npomarede wrote:Hi, thanks for this information,very interesting. I don't think many programs rely on this, but I will add this behaviour to Hatari
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