[Sussex] DB9 to RJ45 - minicom?

[Vic]

>> Yes, but this makes a serial cable using RJ45 connectors, there is no
>> way
>> to use the ethernet port to work as a serial port.
>
> This is correct.  A modern day twisted pair ethernet port (as apposed to
> the old BNC MDI or 15-pin AUI connectors) use different hardware
> configuration to send and receive data.  IIRC (I'm sure a better
> hardware guy here will correct) twisted pair uses voltage differences
> between a pair of wires to send the data signal.  twisted pari ethernet
> uses two pairs of wires, one for send the other for receive.

Whilst that's true, I think the point John was making is that a serial
port is not an Ethernet port, no matter what the physical connection.

> Good old serial, at it's simplest uses only three wires.  One for
> transmit, one for receive and a common ground.  If it uses other wires
> these are used only for handshaking and can be configured to be ignored
> by the hardware.

That's only true for single-ended serial, like RS232. RS422, for example,
uses differential signals over TP, and that's why you get much better data
rates over much longer cables, with much-improved fan-out.

Vic.