Bidirectional modem under ISC 2.2

[John R. Levine]

In article <41212 at cup.portal.com> you write:
>I would like to set up a bidirectional serial port to allow a modem to work
>as either a dial-in or dial-out line.  As I recall, early versions of ISC's
>uugetty program (pre-version 2.2) were broken and never worked properly.

You do not need uugetty to use a port in both directions under ISC 2.2.  As
of the X5 update to 2.0.x, serial ports can have three different special
files: for the first line /dev/acu0, /dev/tty00, and /dev/ttyd0.  You use
/dev/acu0 for dialout with uucp and cu and /dev/ttyd0 for a regular incoming
getty.  The kernel interlocks them automatically.  You can use /dev/tty00
for directly wired terminals or for sending setup strings to the modem at
initialization time.

There is a rumor going around that you need uugetty to use an internal
Telebit modem, due to the modem's not having changable default settings.
This rumor is entirely false -- I've been using X5, then the default 2.2
driver, and now FAS running both ways without uugetty for over a year.
At boot time I send a setup string to the modem with a little program I
wrote, available on request.  Note that if you have an external modem,
this problem most likely doesn't concern you since you can set the modem
to do the right thing all by itself.

Regards,
John Levine, johnl at iecc.cambridge.ma.us, {spdccimaworld}!iecc!johnl