RE: Technical problem (OT)

From: Scott <rylos_at_charter.net>
Date: Fri, 24 Sep 2010 20:39:03 -0400
Message-ID: <001201cb5c4a$0d944ff0$28bcefd0$@net>
Hmmmm... Yes, that would make the ground powered like I stated below. But,
if it were a true ground it would be grounded on the TI85 side, Zero E.

So my answer to the most excellent question would be that the connection to
the LED should be on the 12E side of R3. Is it supposed to flash? Heh... But
even if this is the case there is the polarity issue correct?

-----Original Message-----
From: owner-cbm-hackers@musoftware.de
[mailto:owner-cbm-hackers@musoftware.de] On Behalf Of MikeS
Sent: Friday, September 24, 2010 7:51 PM
To: cbm-hackers@musoftware.de
Subject: Re: Technical problem (OT)

You're assuming that the grounds are actually connected together and at the 
same potential; without studying it in detail I suspect they're inverting 
the signal. Everything is relative...

Also keep in mind that RS-232 signals are +/- 12V (e.g. pin 3 is normally 
at -12V which will light the LED quite nicely)

m
----- Original Message ----- 
From: "Scott" <rylos@charter.net>
To: <cbm-hackers@musoftware.de>
Sent: Friday, September 24, 2010 5:57 PM
Subject: RE: Technical problem (OT)


> Well, the LED can't work. I was thinking that the pin may be miss-labeled
> but no... Pin 5 is signal Ground.
>
> http://www.diyha.co.uk/electronics/comm1.html
>
> Even if the shield had power isn't the polarity wrong?
>
> http://www.diyha.co.uk/electronics/comm1.html
>
> -----Original Message-----
> From: owner-cbm-hackers@musoftware.de
> [mailto:owner-cbm-hackers@musoftware.de] On Behalf Of Ruud@Baltissen.org
> Sent: Friday, September 24, 2010 4:46 PM
> To: cbm-hackers@musoftware.de
> Subject: Technical problem (OT)
>
> Hallo allemaal,
>
>
> I think I found the reason for my email problems. A bit further you
> see "bit......" and that was "bit baCC ngBB MMed". I think there is
> a porno filter active :)
>
>
> I had to buy a TI-84 for my son for school. Quite interesting, it
> has a Z80 on board. It has a bit...... USB interface and another
> bit....... 2-line interface. This particular interface can be
> connected to the RS-232, please se:
> http://www.ticalc.org/hardware/cables/serial.html
> http://www.linkkabel.nl/tutorials/linkkabelmaken/schema.htm
> The second site is Dutch but the schematic is more clear IMHO.
>
> Why this email? I'm puzzled, I have no idea how this can work well
> with the LED between the two Grounds.
>
> If anybody can explain this, please! Thank you!
>
>
> --
>    ___
>   / __|__
>  / /  |_/     Groetjes, Ruud Baltissen
>  \ \__|_\
>   \___|       http://Ruud.C64.org
>
>
>
>
>
>
>
>       Message was sent through the cbm-hackers mailing list
>
>
>       Message was sent through the cbm-hackers mailing list 


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Received on 2010-09-25 01:00:04

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