Radio Shack TRS-80 User manual

PC-4 CASSETTE INTERFACE
OWNERS MANUAL
CATALOG NO. 26-3651
CUSTOM MANUFACTURED FOR RADIO SHACK. ADIVISION OF TANDY CORPORATION

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Thank you very much for purchasing the tape recorder interface.
This interface is an exclusive adapter for connecting any ordinary
tape recorder to the Radio Shack PC-4 pocket computer.
If the cassette interface is connected incorrectly, neither
the computer or the cassette recorder will be damaged;
however, programs or data may not be saved or loaded.
More importantly, valuable data may be erased.
In order to avoid this, please become thoroughly familiar
with the operating procedures outlined in this manual.
Also refer to the computer operation manual.
-4-

Contents
Description 6
How to Connect to the Computer 7
Power Source 8
Functions 9
Requirements for Connecting Tape Recorder 10
Precautions in Connecting Tape Recorder .*11
Setting up for Recording and Playback 12
Program SAVE/LOAD 13
Data PUT/GET 15
All programs SAVE/LOAD 18
File Check 20
Specifications 21
-5-

iPower switch
(If the power switch is turned
on, the remote will operate.)
2Connector for Computer
3Guide for fitting Computer
4Black plug
5White plug
6Gray plug
7For fitting aconnector cap
|Battery lid
yComputer lock/release control
LOCK: Locks the Computer
in place
FREE: Al lows the Computer
to be removed

How to Connect to the Computer
(Precautions)
•Prior to connecting, insure that the power switches of
computer and the cassette interface are off.
•Be careful not to bend the cassette interface connector pins.
the
(1)
(2)
(3)
li
(5)
Turn the computer's power switch off.
Turn the computer lock/release control of the cassette
interface to the FREE position.
Align the top of the computer with the "«" marks.
Line up the connectors of the cassette interface and of the
computer and slide the computer in the direction of the
arrow.
Turn the lock/release control to the LOCK position.
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-7-

Power Source
This adapter uses two AA size manganese dry batteries (Cat.
No. 23-582 or equiv.) tor portable operation. When the bat-
teries run out, the portable operation function will not work
properly. In such case, replace the batteries with new ones.
Installing/Replacing the Batteries
1) Remove the battery lid at the rear of the adapter, by pushing
the knurled area in the direction indicated by the arrow.
2) Remove batteries, and replace them with new batteries.
Observe polarity when putting in new batteries.
CAUTION: Installing the batteries with reverse polarity may
cause them to burst and result in serious damage to
the unit.
3) Replace the lid by pushing it in the opposite direction of the
arrow. You will hear aclick when the lid is back in its locked
position.
#
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Note: 'When replacing the batteries, replace them all.
Replace the batteries every two years even if the port-
able operation function still works properly.
'Do not throw used batteries in afire. They may explode.
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Functions ~~J
1
)
Saves aprogram on atape (SAVE).
2) Loads aprogram on atape into the computer (LOAD).
3) Transfers the contents of the data memories into the tape
(PUT).
4) Transfers data from atape into the data memories of the
computer (GET).
5) Transfers all the programs in the computer into the tape at
once (SAVE A).
6) Transfers all the programs on atape into the computer (LOAD
A).
-9-

Requirements for Connecting Tape Recorder
The cassette interface can be connected to:
Tape recorders that use cassette or microcassette tapes.
Requirements for the tape recorder:
Our portable cassette recorder Minisette-9 (Cat. No. 14-812) is
aperfect mate. However, if you are going to use other tape
recorder, take note of following.
1) The input terminal of the tape recorder (the MICROPHONE
terminal or equivalent) must be (1) 10 kohm or greater in
input impedance, and (2) 3mV or higher in minimum input
level.
2) The output terminal of the tape recorder (the EARPHONE,
MONITOR terminal or equivalent) must be (1) 10 ohms or less
in output impedance, and (2) 2.5 Vor greater in output level.
3) The remote control terminal of the tape recorder (or equiva-
lent) must have aspecification of 24 Vdc, 1Aor less.
4) Total distortion must bo 15% or less.
Most cassette tape recorders currently on the market (radio
cassette recorders, etc.) satisfy these requirements. If your tape
recorder differs slightly, it may still work with the cassette
interface. Note that mismatching will not damage either the
adapter or the tape recorder.
Note: *Use plug adapters (available at Radio Shack store) if
necessary.
*The requirement for the remote control terminal is
important. Make sure that it is met. If not, the
remote control function of the cassette interface may be
damaged.
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