> On 2016-12-26, at 23:51, Michał Pleban <email@example.com> wrote: > > Hello! > > smf wrote: > >> Another method you can use is magic read sequences. i.e. come up with a >> sequence of rom reads that wouldn't happen in normal circumstances, long >> enough to make accidental activation so unlikely that it's practically >> impossible for there to be a collision. Then have the next read after >> this sequence use the address bits as data lines for writing the new bank. > > In this scenario, you don't have the RESET line, so once you select a > KERNAL, you are stuck with it until the computer is switched off. Unless > you can somehow detect the actual reset sequence of the 6510 just by > looking at KERNAL accesses, but I am not sure if it is ever possible. > > If you accept this limitation, then you actually don't need any magic > sequence at all. You just boot into the menu, the user selects the > KERNAL from the menu, then a single read from e.g. $E0xx selects the > KERNAL and disables further selections. That's almost exactly what I bugged you to finish some time ago :-P remember? And also what I now have on my bench as half of my next-gen ROM replacement. -- SD! Message was sent through the cbm-hackers mailing listReceived on 2016-12-27 08:00:02
Archive generated by hypermail 2.2.0.