Umtech VIDEOBRAIN Expander 2 User guide

V id e o B r a in
Home Computer
Accessory
Owner’s
Handbook
A ccessory: Expander 2
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V id e o B r a in
EXPANDER 2
OWNER’S HANDBOOK
Accessory
• Acoustic coupler
VideoBrain Com puter Company
2950 Patrick Henry Drive
Santa Clara, California 95050
All rights reserved including the right of
reproduction in whole or in part in any form.
P/N 40-0033 Rev. 0 8/78
Printed in the United States of America
1

Expander 2 Introduction
Expander 2 data modems are designed fo r acoustic
operation via the switched telephone network or private
line installation. Acoustically coupled with most
telephone sets, the Expander 2 offers a reliable and
convenient method of data transmission.
Expander 2 is an originate-only modem for up to
300 baud operation.
^daaN .
answer
J s ' COMPUTER . / I
EXPANDER 2 s ' s '
h v . VIDEOBRAIN
FIG. 1
2

Controls and Indicators
Following are the controls and indicators found on
the coupler.
Front Panel
1. Full/Half: this switch sets the duplex (communication)
mode of the Expander 2 unit. For half duplex operation
(local copy back), push the switch in. Full duplex
(no copy back) is when the switch is out.
Note: before operating in half duplex mode, make sure
that the system or the terminal does not provide a
local copy back. If so, leave switch in full duplex.
2. PWR: this indicator shows that AC power is applied to
Expander 2.
3. CTS: this indicator shows that a valid carrier signal is
being received from the opposite receiving modem.
Rear Panel
1. On/Off: this switch applies AC power to Expander 2.
2. 115 VAC 60 Hz Only: this grounded 3-wire cord plugs
into any 3-wire 115 VAC 60 Hz receptacle.
3. EIA RS232-C: the 25-pin connector is the standard EIA
RS232-C interface. Plug cable from the Expander 1
right into this connector.
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Installation
AC Power Connection
Expander 2 is provided with a 3-wire power cord which
can be connected to any 115 VAC 60 Hz grounded wall
outlet. Apply power through this cable.
EIA Connection
Plug the supplied EIA cable into the 25-pin EIA
connector in the back of Expander 1 as shown below.
Pin connections and levels conform to the EIA
RS232-C specifications. See the interface chart for
Expander 2.
Plug the other end of the EIA cable into the rear panel
of VideoBrain’s Expander 1 (Input/Output interface).
The modem plug is appropriately labeled on the back
panel of Expander 1, as shown in its Owner’s
Handbook.
EIA
CONNECTOR EIA
CABLE
POWER CORD
FIG 2.
4

Expander 2 Location
For operation, locate a place for Expander 2 close
enough to the telephone so the handset cord can easily
reach Expander 2. Avoid places such as on top of a
terminal, TV set, air conditioner, etc. Some of this
equipment can generate electrical or magnetic fields
which may cause transmission errors.
Operating Procedures
The follow ing is a detailed sequence on how to operate
Expander 2 in a typical tim esharing environment. Insert
Timeshare (CM01) cartridge in the VideoBrain.
Placing a call
1. Turn the AC power switch on. Check that the PWR
indicator illuminates.
2. Choose the proper setting for the Full/Half duplex
switch.
3. Dial the number of the desired computer or remote
station.
4. Listen until the high-pitched carrier tone is heard from
the com puter or the remote station.
5. Place telephone handset in acoustic coupler, with cord
to the rear.
6. Check to ensure that the CTS indicator lights up after
one or two seconds. When this indicator is on, the
exchange of data can begin.
5

Disconnecting a call
When exchanging data with a computer system, simply
sign o ff from the system and the com puter will
disconnect your call.
At any time a disconnect can be accom plished by any
of the two parties by removing the handset and putting
it back in the cradle on the telephone, thereby
disconnecting the line.
Specifications
Data Rate: 300 baud
Modulation: Phase coherent FSK
Operation: Asynchronous, serial by bit
Telephone
Interface: Acoustical via the WE 500 handset
or equivalent
Audio Data
Frequencies: Receive Transmit
Mark 2225 Hz 1270 Hz
Space 2025 Hz 1070 Hz
Tolerance: ±6 Hz ±2 Hz
Receive
Performance: Less than 5% jitte r and 10% bias
distortion operating at 300 baud
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Receive
Sensitivity: Acoustic mode -4 8 dBm ±3 dB,
max hysteresis is 4 dB
Transmit
Level: Pot a dju sta b le- 1 5 t o -21 dBm
Timings: Carrier detect —
on 500 ms ±200 ms
off 50 ms ±30 ms
Clear to send —
on 700 ms ±300 ms
off 2 ms
Power
Requirements: 115 VAC ±10%, 60 Hz, 5 W
Environmental: Operating temperature 0°C to 60°C
Storage temperature -20 °C to 70°C
Relative hum idity 8% to 95% relative
Dimensions: 3%" high
7V2" wide
IOV2" long
N,
Indicators: CTS — Received carrier/clear to send
PWR — Power on
Controls: ON/OFF — Power on/off
FULL/HALF — Duplex
Interfaces: EIA RS232-C
7

Interfaces
Desig. EIA RS232-C Pin Number
AA Protective Ground 1
BA Transmit Data 2
BB Receive Data 3
CB Clear to Send 5
CC Data Set Ready 6
AB Signal Ground 7
CF Received Line Detector 8
+ P Positive Voltage 9 (test only)
- P Negative Voltage 10 (test only)
CD Data Terminal Ready 20 (optional)
8

The Expander 2 Acoustic Coupler is designed and
manufactured for long, trouble-free usage. However, if
any problem should occur, the follow ing chart could
help the operator to diagnose a problem.
Maintenance
DIAG N O STIC CHART
Malfunction: Check:
PWR indicator Is the power cord plugged into
does not illuminate an active outlet?
Is the power switch on?
CTS indicator Check for tone from handset.
does not illum inate Is handset properly inserted
in cups?
Check with the com puter facility
to be sure the system is set-up
for WE 103/113 line protocol 011.
Double characters, If the Full/Half duplex switch is
errors, or no data in Half duplex, switch to Full
exchange at all duplex.
Check the com patibility between
the term inals and the com puter
system; i.e., data rate, character
code, etc.
Check that the tim esharing
service is operating properly.
Check that all cables are
securely connected.

Expander 2 is used with many exciting VideoBrain
cartridges brought to you by the VideoBrain Computer
Company. We suggest you try all the VideoBrain
Cartridges to help you around the home, educate your
children and entertain the whole family.
Money M anag em ent
APL/S The Com putational Language*
VB-81 Financier™
VB-1000 Money Minder*
VB-1200 Inform ation Manager*
Communications
CM01 Timeshare**
Education
ED01 Music Teacher 1
ED02 Math Tutor 1
ED03 Wordwise™ 1
ED04 Wordwise™ 2
ED05 VideoArtist™
ED06 Lemonade Stand— A Business Sim ulation
ED07 Musicanship 1
ED09 Historical Sim ulation— France in the Old Regime
En terta in m ent
EN01 Gladiator
EN02 Pinball
EN03 Tennis
EN04 Checkers
EN05 Blackjack
EN06 Vice Versa™
EN10 Computer Life
*use with Expander 1
**use with Expander 2
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Limited Warranty
For 12 months from date of purchase, VideoBrain
Computer Company w ill repair free of charge any
defect of material and workm anship in the Accessory
electronic circuitry.
For 90 days from the date of purchase, VideoBrain
Computer Company will repair any case or cable defect
in material or workmanship in this Accessory
free of charge.
To obtain warranty service, return the Accessory
postpaid, with sales receipt showing date of purchase,
to the VideoBrain Service Center with address
shown below.
Under no circum stances w ill VideoBrain Computer
Company be liable for any special, incidental or
consequential damages resulting from use or possession
of the VideoBrain or its accessories. However, some
states do not allow the exclusion or limitation of
incidental or consequential damages, so that the above
lim itations or exclusions may not apply to you.
This warranty gives you specific legal rights, and you
may also have other rights which vary from state
to state.
VideoBrain Com puter Company
2950 Patrick Henry Drive
Santa Clara, California 95050
Printed in U.S.A.
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