[svlug] [cisco] minicom to devfs parallal port?

Robert Hajime Lanning lanning at lanning.cc
Fri Oct 4 09:02:53 PDT 2002

On Fri, 4 Oct 2002, Bill Schoolcraft wrote:
> I've been accessing a Cisco router via the standard console port
> on the back of the router and with the transceiver to either
> COM1 or COM2 on the back of a standard pee-cee with no problem.

It is not a "transceiver", it is a converter.  Just wires to swap pins

> I have a Toshiba 1715 with two usb ports and no COM ports but do
> have a RJ45-DB25 transceiver and was going to try accessing the
> router via /dev/lp0 but with devfs it seems to be no-existant.

You cannot do this.  The first thing is that the console port on the
Cisco router is serial. (one data send pin and one data receive pin, it
sends and recieves one bit at a time)

Parallal has multiple data lines (in this case eight data pins).  This port
sends a whole byte at a time (one bit per pin), all pins syncronized.

Becuase of this, the two ports are electricaly (by means of signaling)
incompatible with each other.  (Yes there are ways to convert these ports,
you have to buy a parallel to serial converter, they do exist.)

> (A) Can I use this parallal port with minicom to access the
>     router with the devfs type environment?

I don't know if minicom knows how to talk to the parallel port driver.
You still need to get a parallel to serial converter.  (not just pin swapping)

> (B) Do they make a converter that will do [usb]---->[db9] so I
>     could try that?
Yes they do.  It is usualy called a "USB PDA adapter".
Fry's has it for about $30.


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