Subject: Re: okey, its time to get some more terminals.
To: None <ronny@Update.UU.SE>
From: Ken Wellsch <>
List: port-vax
Date: 09/15/1998 21:46:22
| I haven't been able to get anything at all out of the serial ports on the
| vax :(. I enabled the lines in /etc/ttys, i have created the devices for
| them (ttyS0 -S8), and i see the 8 getty:s running in ps and top. The
| system finds the mux at boot, saying:
| dhu0 at uba0 csr 160440 vec 300 ipl 17
| dhu0: rom(1) version 2 rom(0) version 2
| What are these numbers, and what may i look for ? is any of these numbers
| supposed to be unique (like irq:s in a PC or so), and does this appear
| normal ?

The Control Status Register (CSR) is at address 160440, the interrupt
VECtor is via address 300 and the Interrupt Priority Level (IPL) is 17 for
the device.  I guess the next line is really unnecessary.  The DHV
allows the driver to determine the PROM revision levels, so your PROMs
are Rev-2.  Big deal I suppose.

So on the surface everything sounds like it should be working.  But lets
check some details.  Have you ever had a terminal connected to any of these
ports working in the past?  Have you pulled those bulky ribbon cables too
many times while pulling the CPU/memory and have them in backward now?
Are they also correct when connected to the bulkhead connectors?  I suspect
so but having them reversed I would guess leads to some non-behavior.
(I'm presuming they are even connected at both ends - just teasing 8-)

Do you have a critical serial line tool - a break-out box?  Rather just
the kind of tool with the LED's that gives the status for the key wires?
(e.g. Rx/Tx/DTR/RTS etc.) I found mine (until I packed it away and now
can't find it 8-( ) terribly valuable to give me an instant view of whether
I needed a straight or null-modem cable for example.  Also you can watch
the status change when the getty's start and also see the handshaking with
the terminal when you switch it on.

| I have tried with both crossed and straight cables, three-wire and DEC
| original (25 f to 25 f, known to work between a vt320 and a DECserver
| 200), and at different speeds (all in the vt320 setup).

You may wish to try this same sort of thing with your laptop.  See if
you can get one of your terminals to talk to a getty enabled port on
it.  One of the many wonderful things about NetBSD is that it runs on
nearly everything and the layout is basically the same...


-- Ken