[rescue] Unwilling Crimson

[Francois Dion]

On 1/4/06, Sheldon T. Hall <shel at tandem.artell.net> wrote:
> Quoth Mike Meredith ...
> > On Wed, 04 Jan 2006 20:26:56 +0100, Joost van de Griek wrote:
> >
> > > Nothing comes up on a terminal (VT100, 9600-8N1) attached to any of
> > > the serial ports, either, but we connected that with so many gender
> > > changers and 25-9 converters that it may well have simply been
> > > connected incorrectly.

I had posted this on my website and nekochan a while back, might help
you in the diagnostic:



Hardware
Silicon Graphics console and serial port, desksides

SGI, Starting with the 4D, including the SGI Crimson, and the
Challenge L, XL, Onyx etc, dont use the same pin assignment as IBM
DB-9 assignment. It uses (from the Irix man page for serial) :

The DB-9 female serial port connectors, which are found on the CHALLENGE
and Onyx systems, have the following pin assignments.

-------------------
\ 5 4 3 2 1 /
\ 9 8 7 6 /
---------------

____|______|____________________
2 | TD | Transmit Data
3 | RD | Receive Data
4 | RTS | Request To Send
5 | CTS | Clear To Send
7 | SG | Signal Ground
8 | DCD | Data Carrier Detect
9 | DTR | Data Terminal Ready

Whereas on a laptop or PC (or even other SGI machines like the Octane,
Onyx2 and Origin systems), the DB-9 male serial port connectors have
the following IBM(R) PC/AT(tm)-like pin assignments:

-------------------
\ 1 2 3 4 5 /
\ 6 7 8 9 /
---------------

Pin | Name | Description
____|______|____________________
1 | DCD | Data Carrier Detect
2 | RD | Receive Data
3 | TD | Transmit Data
4 | DTR | Data Terminal Ready
5 | GND | Signal Ground
6 | - | reserved
7 | RTS | Request To Send
8 | CTS | Clear To Send
9 | - | reserved

I figured the SGI didn't need any handshaking, so eliminating the
dtr/dcd and rts/cts, a minimal cable would have:
PC side -> SGI side
pin 2 -> pin 3 (Tx->Rx)
pin 3 -> pin 2 (Rx->Tx)
pin 5 -> pin 7 (Gnd-> Gnd)


Between an onyx and crimson:
pin 2 -> pin 3 (Tx->Rx)
pin 3 -> pin 2 (Rx->Tx)
pin 7 -> pin 7 (Gnd-> Gnd)

Francois