Computer Audio Tape Formats

From: <(>
Date: Tue Dec 17 17:53:01 2002

On Dec 17, 13:50, tim lindner wrote:
> I am looking for information regarding how various computers wrote
> information to audio tapes.

> I am contemplating creating an audio tape anaylzer to help me recover
> some data. I would like to make the program useful to thoes outside the
> Color Computer community. But first I need to understand all of the
> different methods used to put data on audio tape.

Look up "Kansas City" and "CUTS" on the web... many machines used some

For 300 baud:
logic 0 is 4 cycles of a 1.2kHz tone
logic 1 is 8 cycles of a 2.4kHz tone
lead-in is 2.4kHz, followed by a zero byte

Similarly for 1200 baud but fewer cycles.

CUTS (Computer Users Tape Interface) was derived from KC format, which was
so called because it came out of a meeting held in Kansas City in 1975.
 It's backwards compatible.

Also look up Don Tarbell's system. I can't remember what the tones were,
but it's about 600 baud, IIRC.

None of this tells you about the format of the data, of course -- block
headers (if any), checksums/CRCs, etc. That tended to vary.

Pete						Peter Turnbull
						Network Manager
						University of York
Received on Tue Dec 17 2002 - 17:53:01 GMT

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