Radio Shack TRS-80 Modem II Operation Manuals page 19

5.
When
the
other person hears the high-pitched tone, he/she should
set
the
Modem
II
POWER
Switch
to
ON.
6.
When
the
other person hears a low-pitch tone,
he/she should hang-up
the
phone.
You
can then begin
communicating with each
other
by
typing
on your computer's keyboards.
AUTO/ORIGinate
Mode
Operation
Automatic
dialing requires that
you
use
programs
that
have
drivers
and
receivers or write
your
own
program
to dial
a
phone number. Programs
that
successfully
fulfill
your needs can
sometimes become
quite
complicated.
If
you want
to
write
AUTO/ORIGinate
programs,
carefully read the section
of
this
manual
entitled
Technical and
Programming
Information and
refer to the
Appendixes.
To
use the
Modem
II
in
AUTO/ORIGinate
Mode
under
VIDTEX:
1
Set the
Modem's
FORCE DTR
Switch
to
ON.
2.
Enter
programming
mode
(send an
*).
The
TR
Light will
illuminate
and
the
* will echo on
the
Screen,
3
Type
a
Modem
command
and phone number.
Press
X
to dial the
number.
4.
Begin communications
when
the
CD
Light
comes ON.
The
Modem
II
remembers program
data
until
you change
modes
or turn the
POWER
OFF.
Hints
and
Tips
on Automatic
Operation
. . .
• The Modem
II
always checks
the front
panel switch
settings
on power-up and
after a
disconnect.
•
Test
Mode
(when
the
TEST
Switch
is
set to
either
LOCal
or
REMote)
has
priority
over
all
other switches. That
is if
you
set the
MODE
Switches and
then the
TEST
Switch,
the
Modem
II
will
always run
the Test.
•
If
you program
the
Modem
in
Automatic Mode,
the software
commands
will
"override"
the
front
panel switches only once. After
that
first
override, the action
of
the
Modem
will
be
based on
the
switch
settings.
To
override again,
you must go
into
programming mode
and
re-execute
the
Modem
II
program.
9 You
can change
the
switch
settings
during
communications
without interruption.
However,
if
you
set the
TEST
Switch
to
REMote,
the
Modem
will
simulate half-duplex
and
(if
the
Host
isn't
using half-duplex)
your Video Screen
will
display double-characters.
If
you
are
communicating with another person and both of you
set the
TEST
Switch
to
REM,
communication
will end.
See Technical
and Programming Information and
Appendix
B
for details
on "unattended
use"
of the
Modem
II.
Simulating Half-Duplex
To
simulate half-duplex
mode,
set
the Test
Switch
to
REM
after
making
contact with another
computer.
If
your display
shows two
characters for
every
character
you
type,
you
should not
be
simulating
half
duplex
—
set
your
TEST
Switch
to
OFF
and proceed
as usual.
13