Re: DMA successes with Verilog

On 13/06/2018 18:53, Jim Brain wrote:
> The issue, as I understand
> it, is if you want to surreptitiously DMA data into the running 64
> memory map, since you don't know where the 6510 is in it's instruction
> fetch/decode/action cycle, and pulling DMA low will corrupt CPU
> activities in flight.

I would have thought that there would be a safe point if you trigger an 
nmi and switch to ultimax mode when it fetches the vector, have the 
ultimax nmi handler just return and switch out of ultimax mode.

For remote debugging you need to be able to switch to ultimax mode and 
provide code anyway, because you can't update $00/$01 with dma