> On 2016-01-21, at 21:46, silverdr@wfmh.org.pl wrote: > > >> On 2016-01-21, at 21:37, groepaz@gmx.net wrote: >>>>> How do CPU carts access the RAM? I mean how the external CPUs do it from >>>>> the EXPANSION port. >>>> >>>> using the DMA line (which halts the internal CPU and removes it from the >>>> bus) >>> Well, that's what I mean - if all what's needed is to peek a few bytes off >>> some location from time to time? Or is it supposed to be completely >>> invisible to the system? >> >> thats why i asked what exactly the goal is... :) > > True, would be good to know in order to think what's the best approach. But it might be a classified information. Until the product is ready, at least. But since OP thought even of having serial access with extra software, then I reckon taking a few cycles away from the CPU every now and then is less "invasive" than that. OTOH, if the locations are to be only read, while the writes are done by the machine's CPU itself, then it's close to trivial to sip off databus bits triggered by address-bus bit patterns on writes. Did something like that once in the 1541. -- SD! Message was sent through the cbm-hackers mailing listReceived on 2016-01-21 21:07:23
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