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From: scotta@hpcuhd.HP.COM (Scott Anderson)
Newsgroups: comp.sys.handhelds
Subject: Re: casio SF-8000 datalink
Message-ID: <106790005@hpcuhd.HP.COM>
Date: 31 Jan 91 02:44:46 GMT
References: <91028.223328TTL-JJK@finou.oulu.fi>
Organization: Hewlett Packard, Cupertino
Lines: 18


    The chip is an op-amp (a 741 if my memory serves me right - it was
more than a month ago that I tore the thing apart).  The signal coming
out of the BOSS is much less than RS-232 potentials and the op-amp is
used to boost it.  The voltages going into the BOSS get dropped as well
(by a switching circuit based on a 2N2222 transistor, as I remember).
My opinion is that the chances of any passive cable (i.e. just rerouting
where the signals go with no modification) working reliably would be
less than the chances of frying the CASIO with such a cable.

    If you really need more details, let me know and I'll see if I can
dredge up the notes I took.

    Scott Anderson
    An RTEsian and proud of it...		Hewlett-Packard
						Data Systems Operation
    scotta@cup.hp.com				11000 Wolfe Rd.  MS 42UN
    408-447-5219				Cupertino, CA  95014