Re: reading from cassette

[mjmahon@aol.com (Michael J. Mahon)]

Sellam Ismail wrote:

>Everyone who responded to this thread has incredibly over-analyzed the
>problem.  The MP3 file format is lossy.  You can't record cassette-based
>software in MP3 format: it doesn't work.  Try loading it in from the
>original cassette source (if you've got it).  Use a decent cassette player
>and adjust the volume level as appropriate until it loads (you have to
>experiment a little).

Thanks for pointing out what I had ignored!  ;-)

I have generally assumed that 128kbit/s .mp3 compression would
preserve the zero crossings of an Apple cassette, since the subjective
audio quality is superior to cassette tapes.  Boy, was I wrong!

I just did an experiment and found "frame" discontinuities every so often
in the reconstituted .wav file which would certainly cause ERRs if played
into an Apple II.

Lossy compression is not necessarily damaging (in fact Apple II
cassettes could be perfectly compressed, very lossily, by simply
recording the zero crossings), but MP3 was designed to remove
sounds which were inaudible to a _human_ because of masking
signals.  This is definitely not appropriate compression for a 
digital tape.  ;-)

Now, if the OP has .wav files of some cassettes, he should also
be in business...

-michael

Check out amazing quality sound for 8-bit Apples on my
Home page:  http://members.aol.com/MJMahon/