>> Did you try /dev/ttya and /dev/ttyb?
> I did try /dev/ttya (as I need a special Sun wired cable to access
> ttyb?)

You need a slightly unusual cable, but it doesn't have to be from Sun
and it isn't all _that_ unusual.  Sun was uncharacteristically sane in
selecting the pinout; they even stuck fairly closely to a real
standard.  I compared Sun documentation of the pinout with the EIA
RS232C spec - I managed to get a copy through interlibrary loan, some
years back - and found that, for example, ttyb's "Transmitted Data"
signal (the one that is on pin 2 for ttya) is on what RS232C calls
"Secondary Transmitted Data", pin 14.  There are five "Secondary" pins
in the spec, and they all carry the ttyb version of the signal that
ttya has on the corresponding non-"Secondary" pin.  You don't get full
modem control on ttyb - for example, there's no DTR - but you do get
(besides TXD and RXD) RTS, CTS, and DCD.

> but didn't have much luck. I may be slow and not have the right baud
> rate etc or have a broke modem ..

Or a broken serial port, maybe?  If you want to wire up a breakout
cable yourself, here's the pinout:

DB25M	DB25F	DB25F	short	long name from
common	ttya	ttyb	name	my RS232C notes

1	1	1		protective ground
2	2		TXD	transmitted data
3	3		RXD	received data
4	4		RTS	request to send
5	5		CTS	clear to send
7	7	7		signal ground
8	8		DCD	received line signal detector
12		8	DCD	secondary received line signal detector
13		5	CTS	secondary clear to send
14		2	TXD	secondary transmitted data
16		3	RXD	secondary received data
19		4	RTS	secondary request to send

If you are so inclined, you can also wire up more signals for ttya; the
only ones that I would expect you would want to bother with are

6	6		DSR	DCE ready
20	20		DTR	DTE ready
22	22		RI	ring indicator

though 22 of the 25 pins actually have something assigned to them.
(Well, 24 if you count two "reserved for testing" pins.)

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