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
derivative.
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