Beiträge von strik im Thema „MOS6526 CIA detailed test vectors and models“

    I've now been measuring and taking into account the resetting of the SDR shift counter that happens whenever you switch between SPmode input and output - although I've not exhaustively tested those cases yet. Also there is some strange behaviour when you write to SDR while it is in input mode - it seems to skip one input bit in some cases.

    As I am currently working on serial data transfer with the SDR (for OpenCBM and a 1570/1571/1581 drive): can you elaborate a little bit about what you found out? This seems interesting to me.
    I am currently having the case the the transfer works for 3 to 5 MB, but every know and then, the transfer stops. To me, it seems that some byte was skipped. That's why what you wrote above sounds very interesting to me.