Re: A couple //c Serial Questions

[Rubywand <rubywand@swbell.net>]

David Empson writes ...
> 
> Rubywand <rubywand@swbell.net> wrote:
> 
> > To clear up a few possible gaps and glitches in our telecom FAQs
> > ...
> >
> >
> > 1. Is this the correct plug type and pin numbering for a cable connector
> > intended for plugging into the //c serial port?
> >
> >
> >    Mini-Din 5
> > //c Serial Cable
> >   (Male) Plug
> >
> >       |_|
> >    1       5
> >     2     4
> >        3
> 
> Yes (this is the plug, as you indicate).


     Okay; thanks. From Jeff and an email it is clear that the plug is a
DIN; not a mini-DIN. The email also pointed out that the standard DIN 5
socket pinout is ...



       |_|
    3       1
     5     4
        2

So; this means that the //c "DIN 5" pin numbering Apple uses is
non-standard; right?




> 
> > 2. The connection shown below does not seem correct. Will it work as a
> > //c modem cable (supposedly to a modem with a DB9 connector or to a
> > modem using a DB9-->DB25 cable)?
> >
> >
> > DB9 Connector     5-pin male DIN Connector
> > -------------     -------------------
> >
> >     N/C            1 Handshake Out
> >   3 TXD            2 Data Out (TxD)
> >   5 GND            3 Ground
> >   2 RXD            4 Data In (RxD)
> >   4 DTR            5 Handshake In
> 
> The DTR pin is an input to the modem, so this is wrong.
>
> 
> > Is this better ...
> >
> > DB9 Connector     5-pin male DIN Connector
> > -------------     -------------------
> >
> >   4 DTR            1 Handshake Out
> >   3 TXD            2 Data Out (TxD)
> >   5 GND            3 Ground
> >   2 RXD            4 Data In (RxD)
> >   6 DSR            5 Handshake In
> 
> Yes, except that this won't give you hardware handshaking.
>
> To get hardware handshaking, replace pins 4 and 6 on the modem end with
> pins 7 (RTS) and 8 (CTS) respectively.
>

 ....


     Good to have this straightened out. I'll make the corrections to
the FAQs.



Rubywand