About these AIFF by optimux@yahoo.com
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If recording audio CPC TAPE data came from a DIGITAL source, SOME TIMES and DEPENDING OF YOUR SOURCE PLAYER, you must INVERT the polarity of the wave, because DECODER 1.3 (AIFF decoder v1.3 by Pierre Guerrier) don't read "UP polarity". It's easy, write the wave in hard disc, and INVERT the wave (all samples with any AUDIO edition program) to read again with DECODER.

Eg.: They are the same wave from DIGITAL and ANALOGIC source, if you inspect theirs waveforms, you can read a byte in binary:  0 0 0 1 0 1 1 0 ;a 30 in decimal. These was recorded from a Amstrad CPC tape source at 10/11/1999, and are only and example without program or data to process.

 analog rec-polarity-down (ok to read).aif 
 (from a cheap walkman: average quality)

 digital rec-inversed-polarity-up (must be inverted).aif
 (from (DIRECTLY!) CPC HARDWARE PORTS (noise=0): best quality)


 Use SPEED WRITE 0 or 1200 bps to make a good and SECURE translation with DECODER. If DECODER found two files with IDENTICAL "8 BIT" name; first one will be overwriten!!!. DECODER writes AMSDOS disc header format; 8 bytes by name ALLWAYS!. In THIS CASE you must extract portions of AUDIO and DECODE separately. There isn't other way!.



