Date   : Mon, 29 Mar 1999 16:55:39 +0100
From   : "Fraser, Colin J" <Colin.Fraser@...>
Subject: Re: BBC tape to MP3 and back to Beeb

> -----Original Message-----
> From: Christopher J Thornley [mailto:C.J.Thornley@...]
> Sent: 29 March 1999 16:17
> To: bbc-micro@...
> Subject: [BBC-Micro] BBC tape to MP3 and back to Beeb
> 
> How about this suggestion for tape images. The tape only 
> consists of two tone
> one signifying 1 and the other 0.
> These will have a duration dependant on the baud rate i.e. 
> 1200 or 300 baud
> Therefore all you need to store is when the tone has crossed 0 volts.
> So a simple circuit is need to convert this to a digital signal
> 

You can get a cheap FSK decoder chip that will take the tape signal and
generate a serial output to interface to the serial port on your PC much
more reliably than trying to do edge detection on an audio signal. (FSK
decoders use a PLL which smooths out the rough edges...)
That would allow you to transfer tapes to your PC.
The next step would be to write software to take a BBC file image and
generate a WAV file from it that can be played via a soundcard to LOAD the
file into your BBC.
There is a piece of software for an old synthesizer (Roland MC202) on the
web that takes a midi file, and translates it into a WAV file that can be
played into the 202s tape interface, so it can certainly be done. You would
just need to know the details of the BBC tape storage format, and the wav
file format.

I think the idea of MP3s on a CD is not as good as tape files on a plain
audio CD - with MP3s you still need a PC to load up the files.
With an audio CD, you would still have masses of capacity, but would only
need your BBC and a cheap CD walkman to load files.
Having said that, does anyone still have enough tape based software to fill
a CD ?

Colin f