18 Nov
2009
18 Nov
'09
2:52 p.m.
-----Oorspronkelijk bericht-----
Van: cctalk-bounces at classiccmp.org
[mailto:cctalk-bounces at classiccmp.org] Namens Cameron Kaiser
Verzonden: woensdag 18 november 2009 15:05
Aan: cctalk at classiccmp.org
Onderwerp: Re: tape "load and save" to a PC/Mac
The Tutor doesn't save tape as FSK or KCS; it's actually just
pulses, i.e.,
-||-|--|-||-|--|--
It reminds me more of the Commodore Datasette than the Texas
Instruments machines the Tutor was descended from, actually.
The trick with decoding it wasn't per se figuring out the
frequencies, it was figuring out what pulse pattern meant
which bit, and then shuffling the bits around until I got
some sort of framing that made sense. But that's what makes
the playback problem mystifying because this should be very
simple to generate and play back. I don't see what a filter
would do to help here necessarily unless I'm misunderstanding
the alleged purpose.
--
------------------------------------ personal:
http://www.cameronkaiser.com/ --
Cameron Kaiser * Floodgap Systems * www.floodgap.com *
ckaiser at floodgap.com
-- LOAD"STANDARD DISCLAIMER",8,1
----------------------------------------------
And putting your output on a tape and trying to load that ?
Because if that's a working soluntion a filter should do something..
If there tape is generating only pulses the rise time could be affecting the
smitt trigger or other signal shaping circuit.
Another thing, is it possible the tape set some kind of signal like write
enable or read etc..
And last but not least, some tape stored programs have a kind of lead-in
with enables the computer to sync on the tape signal.
-Rik
> Have people discovered any gotchas in
general about using
PC audio
files to
load and save from tape, besides the obvious ones like
don't compress, etc.? Any suggestions about how to make the Mac's
output more acceptable to the Tutor?
A low-pass filter? How does the waveform look on a 'scope?