[comp.sys.atari.8bit] File Transfer

charles@c3pe.UUCP (Charles Green) (04/21/89)

In article <3371@udccvax1.acs.udel.EDU> robby@vax1.acs.udel.EDU writes:
>   I know this questions been answered a ZILLION times, BUT do anyone know
>   of an easy way to transfer IBM PC files to an Atari???

Here's a tack I haven't seen discussed yet, but which I started to implement
some years ago before being distracted by other things:

Find an Exar XR2206 (single-chip, monolithic function generator) and an MC1489
RS232 receiver (or a well-placed diode or two :-).  Wire them up to produce
the same FSK mark and space frequencies as Atari uses for their cassette
interface.  Write an IBM PC application to produce the same headers, trailers,
checksums and IRG as the C: device uses.  Then string it all together with
your favorite portable cassette recorder (or high-quality stereo deck).

Since the XR2206 generates a phase-coherent frequency-shift signal, you will
probably get even better reliability than simply switching between two square
waves as with the Atari recording scheme.  You might even try persuading the
cassette handler to use a baud rate higher than 600 - since I believe that
FSK was used some years ago in a 1200bps half-duplex modem over phone lines
(3kHz bandwidth), you may be able to get away with 4800bps!  (If the 1010
can't quite keep up, you might want to also experiment with the XR2211, which
for me has proven even more reliable at reading Atari tapes than the 1010.)
-- 
"Excuses is not gonna lift up your butt."	-Cher

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