Cassette Interface; Specifications; Block Diagram - Radio Shack TRS-80 26-3650 Service Manual

II.
CASSETTE INTERFACE
(26-3651)
SPECIFICATIONS
Output
terminal:
Input
terminal:
Remote
control terminal:
Data recording format:
Power
source:
Power consumption:
Battery
life
(for
continuous
operation):
Dimensions:
White
mini-plug,
output impedance: approx.
40
kohms,
output
level:
3
~ 50mV
Black
mini-plug,
input impedance: approx. 20 kohms,
input
level:
2.5
~
50V.
Gray
sub
mini-plug,
24V,
1
A
or
less.
Kansas
City standards
(300BPS).
(For
remote
control)
Two
AA
size
dry
batteries.
0.3W.
Approx.
7 hours.
173mmW
X
114mmD
X
31.5mmH.
2.
BLOCK DIAGRAM
D4
6
VODS^
Q.
£
CE2
s
CO
c
Q
E
o
OP
GND
=0
=c>
LSI
HD43110
77
CRYSTAL
OSCILLATOR
FILTER
CIRCUIT
SHAPING
CIRCUIT
REMOTE
CONTROL
CIRCUIT
D
MIC
EAR
REMOTE
£>
3
CO
H
a>
30
CD
8
Q.
CD
LSI
:
Kansas
City standards applied
cassette
tape
interface LSI.
Transfers
serial
data
by
the following
frequencies.
Data"1"
2,340
Hz
Data"0"
1,170
Hz
Filter Circuit:
Converts
LSI's data pulse
into
AC
waveform
for tape recorder.
Shaping
Circuit:
Converts
AC
waveform
data
from
tape
recorder into square pulse for the LSI.
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16-