Re: NEWSFLASH! Linux ported to Commodore VIC-20!!

Neil Conway (nconway.list@ukaea.org.uk)
Mon, 14 Sep 1998 16:47:45 +0000

Alan Cox wrote:
>
> > Hmm, quickndirty calc for 90 minute tape at 64kbits =40megs or so. If
> > you can only get 32kbits then you still get 20megs... The sound
> > engineers among us can no doubt confirm bandwidth and S/N issues, but I
> > would have thought that at least 32kbits would be doable with a little
> > error correction ?
>
> 8bit micro people never got about about 3000bits/second off old cassette
> tape (MFM or FM encoded). Its just horrible stuff for distortion and
> stretching

But 8bit micro people didn't (AFAIK) have error correction... When you
want to download 49152*8 bits for your Sinclair Spectrum game, you can't
tolerate a bit error at all unless you build in error correction and
like I say, they didn't. Hence they had to back it wayyyyy off the
achievable data rate.

Also AFAIK, but this is such a long time ago I could be talking shite,
the Spectrum code used a (slightly) adaptive algorithm, so it could cope
with a little stretching. Obviously, we'd need to do the same.

Think about it this way - tape sound quality is better than phone line
quality, no ? And we can get stereo on 9 decks out of 10... Then build
in the CIRC error correction code and wahey... Maybe 1meg per minute if
we get adventurous ?

Neil

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