[parisc-linux] Help - Serial console problem

Christoph Plattner christoph.plattner@gmx.at
Tue, 16 Oct 2001 23:24:03 +0200


Hello,

I think the problem has to do with the hardware handshake.
The silly M$ OS has the problem, that it expects correct
settings of the hardware handshake lines, although hardware
handshake is not used. The same is true for the default BIOS
(int 14h) driver. On Linux, for example, this problem is
not present.

The PC under any Microsoft system or under BIOS (int 14h)
control does not send any character, if the CTS line (pin
5 on the D-SUB-25) is active. A linux PC used via serial
console on a Win2000 system is working, as the Linux PC
activates the lines, although it is not using them. 

So sum up: Windows expects on the input side an active
CTS to send. Linux does not require this line active,
but activates the output for a machine on the other side,
who needs the output active. 

The HP workstation and server (so my HP 55E 9000/856) do
not activate the handshake line, so the CTS pin on the
Win2000 side is inactive. Is was not possible for my to
activate the handshake lines on the HP server via `stty'.

The most simple method to get it working:
Make a special cable with a 3-wire conection to the HP
machine (TXD, RXD, GND) and solder two bridges on the
Win2000 side in the connector:
	for 25-pin:  	4 <-> 5
			6 <-> 20

	for 9-pin:	7 <-> 8
			4 <-> 6

This should work then ....


With friendly regards
	Christoph P.


Grant Grundler wrote:
> 
> paul lee wrote:
> > I could not access a C200 workstation via serial
> > console. Could someone please give me some insight?
> > I use hyperterminal on Win 2000. The settings are
> > VT100, 9600, 8-N-1 and Xon/Xoff.
> 
> The settings are correct.
> It's possible the serial cable isn't wired correctly
> or the C200 isn't trying to use serial port1.
> 
> grant
> 
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