Re: Cassette port input frequency range? And CPU MHz ranges.

[Kevin Dady <kevin@hackaday.com>]

On Nov 27, 2:44 pm, Egan Ford <dataj...@gmail.com> wrote:
> On Nov 27, 12:19 pm, dog_...@macgui.com (D Finnigan) wrote:
>
> > Egan Ford wrote:
> > > I just spent my yesterday creating a new cassette input method that is
> > > ~11x faster than the original (I loaded moon patrol in 10 sec vs.
> > > 109), and while it works with Virtual ][, it fails on the real thing.
>
> > > Questions:
>
> > > 1.  Does anybody know the upper frequency limit of the cassette input
> > > port?
>
> > The limitation is the microprocessor frequency, as well as the time it takes
> > to execute the necessary instructions to address the cassette port.
>
> Yes, clearly.  Let me restate my question.  Is there any obscure HW
> limitation not emulated in emulators that would prevent higher
> frequencies to be used.

not that I know but you have to keep in mind what emulators are, which
is software implementations of other hardware than what you physically
have .. the apple II does not have 16+ bit sound cards with buffers
while being backed up with gigs of ram and multicore multigigahertz
computers with multitasking operating systems.

On the other side your emulator is not directly tickling bits of
silicon in the sound card, so there is a gap... your linux/windows/osx
os and supporting hardware is taking the data from your sound card
(which probably has more cpu power than the apple II) and is piping it
though many layers of software to the emulator software, where it is
handled once again thought the OS, and then directed to a virtual
machine