Also, can this be done on a 128? On Wed, Dec 28, 2016 at 11:13 AM, Payton Byrd <plbyrd@gmail.com> wrote: > So Jim, > > How long should I wait before ordering a JiffyDOS with this feature? > > On Wed, Dec 28, 2016 at 10:06 AM, Gerrit Heitsch < > gerrit@laosinh.s.bawue.de> wrote: > >> On 12/28/2016 04:29 AM, Jim Brain wrote: >> >>> On 12/27/2016 10:36 AM, Gerrit Heitsch wrote: >>> >>>> On 12/27/2016 11:56 AM, Michał Pleban wrote: >>>> >>>>> >>>>> 1. Have the CPLD check for reset vector access, that is, for a fetch >>>>> from $FFFC immediately followed by a fetch from $FFFD. This will catch >>>>> the reset sequence as well as JMP ($FFFC) which is also a kind of >>>>> reset, >>>>> but it will not catch other accesses to the vector like LDA $FFFC. >>>>> >>>> >>>> Don't forget that CPU memory access is interleaved with VIC. So you >>>> won't see an access to $FFFC immediatly followed by an access to >>>> $FFFD, there will be at least one access to wherever inbetween. If >>>> you're unlucky and catch a badline there will be more... >>>> >>>> In order to filter out the CPU accesses, you will have to also look at >>>> AEC, RDY and PHI0. >>>> >>>> Gerrit >>>> >>>> >>>> >>>> Message was sent through the cbm-hackers mailing list >>>> >>> I don't think that is correct. >>> >>> As I look at the schematic, I don't see where the VIC memory accesses >>> would select the ROM IC via the PAL, and so can't you just gate on !CE >>> (or !CE/!OE on larger ROMs) to ensure that only CPU accesses are watched? >>> >> >> You can do that, yes, since VIC will not access the KERNAL ROM. But you >> still need to take the possibility of a badline in the middle of the vector >> fetch into account. >> >> >> Gerrit >> >> >> >> Message was sent through the cbm-hackers mailing list >> > > > > -- > Payton Byrd > <http://t <http://www.paytonbyrd.com>hesharp.ninja> > <http://it.toolbox.com/blogs/paytonbyrd> > -- Payton Byrd <http://t <http://www.paytonbyrd.com>hesharp.ninja> <http://it.toolbox.com/blogs/paytonbyrd> Message was sent through the cbm-hackers mailing listReceived on 2016-12-28 18:01:21
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