[unix-pc.general] difference between ph1 and tty000

rs@mhuxu.UUCP (Bob Sanderman) (01/19/89)

I'm trying to capture data coming into a 7300 via modem.
The following command works fine when I have a 1200 baud modem
attached to tty000:

(stty 1200; cat > /tmp/data) < /dev/tty000

When I run this the cat command will wait until the modem answers
and all data is transmitted before exiting.

If I change /dev/tty000 to /dev/ph1 the cat immediately returns
without waiting for any data or even the modem to answer a call.

How can I get /dev/ph1 to work?

Thanks
Bob Sanderman
att!mhuxu!rs

ditto@cbmvax.UUCP (Michael "Ford" Ditto) (01/20/89)

In article <8974@mhuxu.UUCP> rs@mhuxu.UUCP (Bob Sanderman) writes:

[    (stty 1200; cat > /tmp/data) < /dev/ph1    ]

> the cat immediately returns
>without waiting for any data or even the modem to answer a call.

This is because of a fundamental design flaw in the Unix PC's phone driver.
The device can only be opened for data transfer using the WRONLY or RDWR
modes; opening it for input results in the driver being in "voice" mode
which is really meant only for the phone manager's use.

I recently posted a driver "patch" (called "phfx") that will completely
eliminate voice mode from the driver.  This will let your example command
work, but at the expense of eliminating the phone manager.
-- 
					-=] Ford [=-

"The number of Unix installations	(In Real Life:  Mike Ditto)
has grown to 10, with more expected."	ford@kenobi.cts.com
- The Unix Programmer's Manual,		...!sdcsvax!crash!elgar!ford
  2nd Edition, June, 1972.		ditto@cbmvax.commodore.com