[sebhc] H8-5

Carroll Waddell carrollwaddell at sc.rr.com
Mon May 22 20:57:51 CDT 2006

William Elkins wrote:
> While it is true the audio from a cassette player is not synced the
> waveform that was recorded on the cassette was. Bit transistions
> occured at zero crossing on the carriers. If your clock and pc uart
> are running independantly your bit transistions will rarely occur at
> zero crossing. At 1200 bps the available number of carrier cycles per
> bit of data is one or two depending on which state the data line is
> in. At 300 bps you get 4 cycles or 8 cycles and the phase relationship
> between the clock and the data is less important.
> Bill
>> At this point, all I'm trying to do is make the H8-5 think something
>> else is a cassette player.
>> I'm trying to feed the H8-5 AUDIO INPUT with tones just like the sound
>> coming from a cassette player.
>> The audio from an actual cassette is not sync'd to anything. The PLL on
>> the H8-5 creates the clock from the audio coming from the cassette 
>> player.
>> I haven't started to try to create the WRITE half of the project yet.
>> I'm still just trying to make the H8 think I have an actual cassette
>> player with a tape to load in it.
>> Carroll
> -- 
> Delivered by the SEBHC Mailing List
Thanks. I hadn't thought of that.

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