PacComm TINY-2 - Page 133

HARDWARE
DESCRIPTION
Modem
Disconnect
-
Jo
Pin
1
Carrier
Detect
Input
This
pin
tells
the
SIO
radio
port
that
a
valid
data
carrier
has
been
detected.
It
shoutd
be
pulled
high
when
no
carrier
is
detected
and
low
when
a
carrier
is
present.
It
is
normally
jumpered
to
pin
2
when
the
on-board
modem
is
used.
Pin
2
Carrier
Detect
Output
This
pin
is
an
output
from
the
on-board
modem
{via
an
inverter
gate)
and
provides
the
necessary
signals
tequired
by
pin
1
above.
It
is
normally
jumpered
to
pin
1
when
the
on-board
modem
is
used.
Pin
3
SIO
Special
Interrupt
Input
This
pin
is
routed
to
the
radio
port
DCD
input
pin
on
the
SIO. This
pin
is
normally
jumpered
to
pin
4
when
the
on-board
modem
is
used.
Pin
4
SIO
Special
Interrupt
Generator
Output
This
signal
is
an
output
from
the
on-board
modem.
it
is
normally
jumpered
to
pin
3
when
the
on-board
modem
is
used.
Pin
5
SIO
RTS
Output
This
signat
is
used
for
transmitter
activation.
It
activates
the
PTT
pin
of
the
radio
connector
via
the
watch-dog
timer.
The
SIOwill
pull
this
output
low
when
the
TINY-2/MICRO-2
wants
to
transmit;
otherwise
it
will
remain
high.
This
pin
is
normally
jumpered
to
pin
6
when
the
on-board
modem
is
used.
Pin
6
Modem
RTS
Input
This
signal
is
an
input
to
the
on-board
modem.
It
should
be
left
high
and
pulled
tow
only
when
transmission
is
desired.
This
pin
is
normally
jumpered
to
pin
5
when
the
on-board
modem
is
used.
Pin
7
CONNECT
Status
Output
This
pin
is
an
output
from
the
SIO.
Itis
normally
low
and
goes
high
only
when
the
TINY-2/MICRO-2
is
in
a
connected
state.
Its
status
is
reflected
by
the
CON
LED.
Pin
8
Unacknowledged
Packets
Pending
Status
Output
This
pin
is
an
output
from
the
SIO.
itis
normally
low
and
goes
high
only
when
the
TINY-2/MICRO-2
has
unacknowledged
packets
in
its
trans-
mit
buffer.
Its
status
is
reflected
by
the
STALED.
Pin
9
SIO
CTS
Input
This
pin
is
an
input
to
the
SIO.
It
is
high
when
the
attached
modem
is
not
ready
to
accept
data,
and
fow
when
the
attached
modem
is
ready
to
accept
data.
The
packet
controller
will
not
attempt
to
send
data
when
this
pin
is
high.
This
pin
is
normally
jumpered
to
pin
10
when
the
on-board
modem
is
used.
Pin
10
Modem
CTS
Output
This
pin
is
used
by
the
on-board
modem
to
signal
the
SIO
when
it
is
ready
to
accept
data.
This
pin
is
normally
jumpered
to
pin
9.
Pin
41
Transmitter
Clock
(16x)
input
This
pin
is
tied
to
the
NRZ-to-NRZI
converter,
which
expects
a
clock
signal
at
16
times
the
desired
radio
port
data
rate,
e.g.
4800
Hz
for
300
bauds.
This
pin
is
normally
jumpered
to
pin
12
when
the
on-board
modem
is
used.
nO
42
TINY-2/MICRO-2
Technical
Ref.,
2
Ed
©
1989,
PacComm,
Inc.