Re: Theorizing: what can be done with DOT clock signal present on C64 expansion port?

On 04/11/2021 19:46, Claudio Sánchez wrote:
> This would work as "send data to an external sound processor with its
> own memory and let it do the work". The dot clock would allow for
> internal upsampling or extra DSP effects that the SID wouldn't be able
> to do and would be too expensive to do in software by the CPU.
>
What external sound processor and what data? If you want to send MP3
then the DOT clock is too low, if you want to send ADPCM then the DOT
clock is too high.

> The ability of doing DMA from outside would be helpful so the CPU
> would ask for certain calculations to be done by the external math
> coprocessor by presetting certain memory locations with both the
> operations and the data to be processed, and then asking the external
> chip to do them. Things like 3D games, database applications,
> spreadsheets, graphics suites... would benefit from it.
>
You wouldn't use the DOT clock for DMA though.

I think you misunderstand what the DOT clock is.