On Fri, Jun 15, 2018 at 1:05 AM, <silverdr@wfmh.org.pl> wrote: > > >> On 2018-06-14, at 23:38, Nejat Dilek <imruon@gmail.com> wrote: >> >> Do CIA chips really keep the NMI low if they don't get an ACK? I don't >> think so. > > This is a known (Marko did it first?) software technique for preventing NMIs coming e. g. off the RESTORE key on a 64 and spoiling the precise raster synchronisation. > > -- > SD! - http://e4aws.silverdr.com/ > > I already know it but I'm not talking about software. I'm talking about hardware and my comments were to the statement "which would hold the NMI line down, preventing NMI from working". I shared my doubt as to the "line being held low" or "hardware generating nmi just waiting for an ACK and not generating any more nmi interrupts.". I think the latter is correct. Since NMI to be generated by this special hardware, running software on the c64 can't prevent it happening. Marko Makela's finding is only relevant for the stock hardware. Regards, NejatReceived on 2018-06-15 01:00:58
Archive generated by hypermail 2.2.0.