User`s guide
Vector
ZCB
Single
Board
canputer
1200 baud
or
less:
Use a
25-wire
ribbon
cable,
with
male
IE-25
connectors
at
both
ends.
(TI
810
has
a
female
connector
at
its
rear,
as
does
the
ZCB
Serial
I/O
cable.)
On
both
ends
of
this
rnale-to-male
cable,
pin
1
is
the
u~r
left-harrl
pin
when
looking
bDward
the
connector's
pins
and
holding
the
connector
so
that
the
longer
roW'
of
pins
is
on
top.
Alternately,
you
can
create
a 2
wire
cable
connecting
lines
3
and
7
straight
through,
and
using
a male
IE-25
at
both
ends,
as
described
above.
In
addition,
you
MUST
solder
a
jumper
between
pins
6,
8,
and
9
at
the
printer
end
of
the
cable,
in
order
to
enable
the
printer.
(The
printer
provides
+12
VDC
on
line
9,
and
requires
+12
VDC
on
lines
6 arrl
8.)
2400 baud
or
more:
Since
the
TI
810
printer
can
print
no
faster
than
150
characters
per
second,
which
corresponds
to
1500
baud,
transmitting
at
a
rate
of
2400 baud
is
too
fast
for
the
printer
using
the
cable
connection
described
above.
However,
the
TI
810
can
receive
at
up
to
9600
baud.
This
is
feasible
if
the
canputer
monitors
line
11
caning
fran
the
printer.
The
printer
pulls
line
11
down
to
-13
VOC
when
it
cannot
accept
any
rrore
characters,
arrl
otherwise
holds
line
11
at
+12
VDC.
Line
11
is
called
"printer
busy
status.
n
Since
incoming
line
4
on
the
ZCB
board
is
connected
to
RI'S,
'connect
RS-232c-
line
11
to
line
4
at
the
canputer
connector
or
the
printer
cdnnector.
What
the
above
accanplishes
is
to
connect
the
printer
busy
status
line
to
the
crs
input
of
the
8251
so
that
when
the
printer
signals
it
cannot
accept
more
characters,
crs
is
pulled
up,
which
disables
the
8251
transmit
circuit
which
in
turn
prevents
software
fran
sending
characters
to
the
8251.
This
assumes
the
software
polls
the
8251
TxRDY
status
bit
or
is
interrupt
driven
by
the
TxRDY
line.
The former
is
true
for
all
serial
printer
drivers
from
Vector
Graphic
at
the
ti:ne
of
this
writing.
Note:
When
the
canputer
is
sending
a
great
deal
of
data
to
the
TI
810
directly
fran
rrerrory
without
any
pauses
at
all,
even
1200
baud
is
too
fast.
The
result
will
be
occasional
loss
of
a
line
of
cutput.
This
will
not
happen
wi
th
most
business
software
or
program
assembly,
because
there
are
many
pauses
for
disk
access
and/or
calculation.
It
may
happen
however
when
printing
editor
or
word
processor
text
directly
fran
rrerrory.
If
you
expect
to
encounter
this,
install
the
modification
given
above
under
"2400 baud
or
more"
if
the
printer
is
used
at
1200 baud.
2-14
Rev.
l-B
6/11/80