Radio Shack TRS-80 26-3650

3.
LSI
(HD43110)
HD431
10 is
a
cassette
tape
interface
LSI
with
Kansas
City
standards
which
transfers
data between
the
CPU
and
cassette
tape
recorder.
Data
"0"
and
"1"
are
transferred
in
serial as 1,170
Hz and 2,340
Hz
frequency
pulse
respectively.
Data is
transferred
at 300
bits
per
second.
The
following
lists the
functions
of
each
terminal
of the
LSI.
Pin
No.
Signal
Name
In/Out
Function
2
OSC
In
Clock
pulse
(32,768Hz) input.
7
VDD'
Out
-3V output.
8
CONT
In
The
LSI
functions
only
when
the
terminal is
HIGH.
9
VDD1
In
-3V
input.
10
CE
In
Chip
enable
terminal.
The
LSI
is
designated
from
PC-
4
when
the
terminal is
HIGH.
11
SP
In
Strobe
pulse input
from PC-4.
13
D4
In/Out
Serial data
input/output.
14
GND
In
0V
input
terminal.
17
C3
In
Data
input
from cassette
tape.
18
C2
Out
Data
output
to
cassette
tape.
19
C1
Out
Remote
control
(auto stop)
signal
output.
-
17
-