Am Sonntag, 10. Juni 2018, 15:26:47 CEST schrieb Francesco Messineo: > On Sun, Jun 10, 2018 at 3:22 PM, Gerrit Heitsch > > <gerrit@laosinh.s.bawue.de> wrote: > > On 06/10/2018 03:03 PM, Francesco Messineo wrote: > >> On Sun, Jun 10, 2018 at 2:49 PM, Clockmeister > >> > >> <clockmeister@internode.on.net> wrote: > >>> I know nothing of such things, but would it be easier and cheaper to > >>> > >>> simulate a 6526 using an Atmel controller(s) of some kind? > >> > >> probably the best thing would be re-creating a clone of the 6525 in a > >> MAX7000 (5V series) CPLD. I can help (but I haven't a lot of spare > >> time) if anyone likes doing that. > > > > Might not be possible since the 6525 has NMOS output drivers which allow > > you to do things that you can't do with CMOS output drivers. Namely > > having 2 outputs (one LOW, one HIGH) directly connected. > > if this "feature" has really been exploited, then it could be probably > emulated with open drain outputs or other "tricks" (like series > shottkys) but it really depends if and how it's used. if its similar as with what ppl did with 6522 and 6526 (i would assume it is) - then expect every dirty trick you can imagine being used by real world software. for example even the subtle differences between the port drivers of port 1 and port 2 are relevant in 6522/26 emulation. -- http://hitmen.eu http://ar.pokefinder.org http://vice-emu.sourceforge.net http://magicdisk.untergrund.net Aesthetic delight lies somewhere between boredom and confusion. <E.H.Gombrick>Received on 2018-06-10 16:01:49
Archive generated by hypermail 2.2.0.