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

[Egan Ford <datajerk@gmail.com>]

On Nov 27, 7:04 pm, mwillegal <m...@willegal.net> wrote:
> Take a look at the sync signal used on the stock Apple 1 and Apple II cassette interface on this page.
>
> http://www.willegal.net/appleii/aci.htm
>
> Though the circuit works as a zero crossing detector, there are clear limits as to speed capability due to the relatively slow signal transition times on the comparitor side of the input capacitor.
>
> You may get a bit more out of it, by using a digital music player which eliminates some the analog jitter involved with a real cassette player, but I'd be surprised if you could get 10x improvement.
>
> Regards,
> Mike Willegal

Thanks Mike, that is what I was afraid of.  I'll run some tests in a
week or two and try to measure the peak effective frequency for my //
e.

Right now I have an effective baud rate of 1777 @ 8 bits giving me
~10x.  But that requires a sampling rate of 64K and a range of
frequencies from 1032 to 32K.  It works in emulation, but not in the
real world.