Black Box AC082A User manual

CUSTOMER
SUPPORT
INFORMATION
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Mail order: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018
Web site: www.blackbox.com • E-mail: [email protected]
AUGUST 1993
AC082A
Dual System Video Converter
Dual System Video Converter
UNDERSCAN
NORMAL
FL ICKER REDUCTION
NORMAL
FREEZE IMAGE
NORMAL
POWER
LOCK

1
FCC AND IC STATEMENTS, TRADEMARKS
FEDERAL COMMUNICATIONS COMMISSION
AND
INDUSTRY CANADA
RADIO FREQUENCY INTERFERENCE STATEMENT
This equipment generates, uses, and can radiate radio frequency energy
and if not installed and used properly, that is, in strict accordance with the
manufacturer’s instructions, may cause interference to radio
communication. It has been tested and found to comply with the limits for a
Class A computing device in accordance with the specifications in Subpart B
of Part 15 of FCC Rules, which are designed to provide reasonable protection
against such interference when the equipment is operated in a commercial
environment. Operation of this equipment in a residential area is likely to
cause interference, in which case the user at his own expense will be required
to take whatever measures may be required to correct the interference.
Changes or modifications not expressly approved by the party responsible
for compliance could void the user’s authority to operate the equipment.
This digital apparatus does not exceed the Class A limits for Radio noise emission from
digital apparatus set out in the Radio Interference Regulation of Industry Canada.
Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les
limites applicables aux appareils numériques de la classe A prescrites dans le
Règlement sur le brouillage radioélectrique édicté par Industrie Canada.
TRADEMARKS
Black Box and the logo are registered trademarks of Black Box
Corporation.
RCA®is a registered trademark of General Electric Co.
UL®is a registered trademark of Underwriters Laboratories Incorporated.
Mac®is a registered trademark of Apple Computer, Inc.
Macintosh®is a registered trademark of Apple Computer, Inc.
Sharp®is a registered trademark of Sharp Corporation.
Any other trademarks mentioned in this manual are acknowledged to be the property
of the trademark owners.

2
DUAL SYSTEM VIDEO CONVERTER
Table of Contents
Chapter Page
1. Specifications .......................................................................................... 3
2. Introduction ........................................................................................... 4
3. Installation .............................................................................................. 5
3.1 Initial Steps ...................................................................................... 5
3.2 Hooking Up Video Output ............................................................. 5
3.3 Selecting Your Video Standard ....................................................... 6
3.4 Final Preparations ............................................................................. 6
4. Operation ............................................................................................... 7
4.1 Indicators ......................................................................................... 7
4.2 Front-Panel Controls......................................................................... 7
4.3 Operational Parameters .................................................................. 8
5. What to Expect from Converted Computer Images ............................ 9
6. Troubleshooting ................................................................................... 11
Appendix A: S-Video, the Improved Quality Video Standard ................... 12
Appendix B: Connector Pinouts ................................................................. 13

3
CHAPTER 1: Specifications
Video Input Standards — VGA or Mac®
Video Output Standards — VGA or Mac; NTSC or PAL: Composite video,
S-Video, RGBS
Modes Supported — All VGA: 200, 350, 400, and 480 line
Mac: 640 x 480
Up to 16.8 Million Colors (24-bit Color)
Controls — (1) rear-mounted slide switch: NTSC/PAL
(3) front-mounted toggle switches: Underscan,
Flicker Reduction, Freeze Image
Indicators — LEDs: (1) Power, (1) Lock
Connectors — Computer Input: HD-15S
Computer Output: HD-15S
(buffered pass-through of input)
Composite Video Output: RCA
®
Phono Jack
S-Video Output: 4-Pin Mini-DIN Jack
Expansion/RGB Output: HD-26S
Power — Separate Universal AC Power Supply
Input: 95 to 250 VAC, 47 to 63 Hz
Output: 5 VDC @ 3.8 A
Regulatory Approvals: UL®, CSA, and TUV
Size — Converter: Width: 7.25" (18.4 cm)
Height: 1.5" (3.8 cm)
Depth: 6.25" (15.9 cm)
Power Supply: Width: 2.75" (6.9 cm)
Height: 1.5" (3.8 cm)
Depth: 4.75" (12.1 cm)
Weight — 2.9 lb. (1.3 kg) (includes power unit)
1. Specifications

4
DUAL SYSTEM VIDEO CONVERTER
O VERVIEW
The Dual System Video Converter
will enable you to convert your
computer monitor signal into a
form suitable for VCR recording,
conventional TV or video monitor
display, or integration into a
multimedia production system.
The Dual System Video Converter
is a plug-and-play unit. After you
have connected it to your equip-
ment, you are ready to go.
By adding the Sync Genlock
(available separately), you can
have full studio timing capability,
providing control over both
subcarrier and horizontal timing.
P ACKAGE C ONTENTS
• Dual System Video Converter
• Universal input power supply
• AC line cord for North America or
Continental Europe
• 6-foot
(1.8-m) VGA computer input cable
• 6-foot
(1.8-m) Mac computer input cable
• 8-inch (20.3 cm) Macintosh
®
monitor
adapter cable
• 12-foot
(3.7-m) composite video output
cable
• 12-foot (3.7-m) S-Video output cable
• This manual
OPTIONAL ACCESSORIES
• Sync Genlock
• 12-foot (3.7-m) BNC adapter cable,
Sharp
®
projector cable, or SCART cable:
for the Converter’s RGB/Expansion
output
• RF Modulator for North America
channels 3 and 4
2. Introduction
OUTPUTS NTSC PAL
COMPUTERS-VIDEO VIDEORGB/EXPANSION COMPUTER IN POWER
GENLOCK
SYNC
TO SCAN CONVERTER
EXPANSION PORT
BLUEGREENREDOUTIN
OUTPUTS
Figure 1. The Dual System Video Converter allows you to output your
computer monitor signal to three video devices.
Optional Sync Genlock (AC083A)
(with HD26 to HD26 expansion cable) Dual System Video Converter
Reference
(Black Burst)
Video
Projector
Video
Monitor
VCR
Computer
Monitor
Computer
Output
Power
Supply
To
Chroma
Keyer or
RGB
Monitor
optional

5
CHAPTER 3: Installation
3.1 Initial Steps
1. Disconnect your monitor (if it
is connected) from the monitor
port on your computer.
2. Connect one end of the provided
6-foot cable to the monitor port
on your computer. Connect the
other end in to the connector on
the rear panel of your Converter
labeled COMPUTER IN. See
Figure 2.
3. If you want your monitor to
continue to display, connect it
to the output connector labeled
COMPUTER on the rear panel
of the Converter. See below for
a description of this output.
Note for Macintosh users: Attach
one end of the 8-inch Macintosh
adapter to the Converter, the
other to your cable that connects
to your monitor. Do not use your
cable to connect your Mac
computer to the COMPUTER IN
connector on the Converter.
4. Attach the power supply provided
with the Converter to the
connector labeled POWER. Plug
the AC-line cord into an outlet to
provide power to the Converter.
The front-panel red POWER
indicator should light. (If you
ever need an AC-line cord specific
to another country, please call
your sales representa-tive in
that country.)
3.2 Hooking Up Video Output
Now connect one or more of the
Converter’s four output ports to
your video equipment: All outputs
are available at the same time.
Unused outputs do not have to
be terminated.
COMPUTER: This output is a
pass-through of the COMPUTER IN
input. You can connect a standard
computer monitor (or a multi-sync
monitor if your system supports it)
to this output.
VIDEO: Feed this single
composite-video output signal into
the “video” input jacks on ordinary
TVs, monitors, VCRs, or profes-
sional video equipment by using
the included composite-video cable.
This signal cannot be fed into the
“antenna” input of a television
or VCR.
S-VIDEO: Called S-Video, S-VHS,
or Y/C, this output is an advanced
form of video which carries the bright-
ness and color parts of images on
two separate signals. It is compatible
with the Hi-8 and Beta-ED standards.
Feed it into compatible equipment
by using the included S-Video cable
and you’ll get a better-quality picture
than the VIDEO output can provide.
3. Installation

6
DUAL SYSTEM VIDEO CONVERTER
RGB/EXPANSION: This premium-
quality output, which can be used by
some video projectors and monitors,
consists of separate red, green, blue,
and sync signals. Feed the signal into
compatible equipment by using our
optional RGBS cable with BNC
connectors, European SCART
connectors, or connectors for
Sharp LCD projectors. Call Black
Box to order these cables.
3.3 Selecting Your Video Standard
Use the NTSC/PAL slide switch on
the back of your Converter to choose
which standard you’ll use for the
VIDEO, S-VIDEO, and RGB outputs.
NTSC is the video standard for the
USA, Canada, Mexico, Japan, and
parts of South America. PAL is used
throughout most of Europe, the
Middle East, Southern Asia, and
the Pacific Rim.
3.4 Final Preparations
Turn on your computer. The green
indicator labeled LOCK on the
Converter’s front panel should light,
showing that the Converter is
receiving a proper signal from the
computer. (Refer to the next chapter
for an explanation of this indicator.)
Make sure the FREEZE IMAGE
switch on the front panel is in the
NORMAL position, so that your
computer-image sequences will flow
smoothly.
OUTPUTS NTSC PAL
COMPUTERS-VIDEO VIDEORGB/EXPANSION COMPUTER IN POWER
Figure 2. Rear panel of the Dual System Video Converter.
Highest quality RGBS
at 15.75 kHz (also
Genlock Sync)
S-Video for separate,
clearer Y/C video signals
Baseband video signal
for standard video
equipment
NTSC/PAL switch for
selecting the appropriate
video standard
Buffered Mac or VGA
video signal for local
computer monitor
Mac or VGA video
signal input from
computer
Power supply
(line cord from
transformer
connects here)

7
CHAPTER 4: Operation
4. Operation
Operating your Dual System Video
Converter is very simple. There are
few controls to adjust and no hidden
DIP switches to set. The Converter
will feel warm when operating. This
is normal. To avoid overheating, do
not place any object on top of the
Converter.
4.1 Indicators
The red POWER indicator lights up
when your Converter is receiving DC
power. If this light is glowing dimly
or not at all, there might be
something wrong with the external
power supply. See Chapter 6.
The green LOCK indicator lights
when the Converter is receiving a
valid computer signal through the
COMPUTER IN connector on its
rear panel. Which video-display
mode the Converter will use
depends on the monitor attached
to the COMPUTER port (see
Section 4.3).
4.2 Front-Panel Controls
UNDERSCAN: When this switch
is in the NORMAL position, images
that the Converter outputs in
Composite, S-Video, and RGBS
formats will fill the entire viewable
screen area. Because some monitors
“overscan” their screens, some
desirable parts of your images could
be cropped off of the screen. If this
is the case, flip this switch to the
UNDERSCAN position to shrink
the images, both horizontally and
vertically, approximately 10% in size.
FLICKER REDUCTION: When
this switch is in the NORMAL
position, the Converter sends images
using fully interlaced Composite,
S-Video, and RGBS video signals.
However, thin horizontal lines in
the images might appear to “flicker”
on and off at a very fast rate. This
annoying flicker, if present, can be
virtually eliminated by setting this
switch to the FLICKER REDUCTION
position. There is a trade-off with this
feature: you might notice a slight loss
of vertical resolution, detail, or
brightness.
FREEZE IMAGE: You might want
to freeze an image on the screen
without altering or discontinuing
your software application. If this
switch is moved to the FREEZE
IMAGE position, the image on the
Composite, S-Video, and RGBS
outputs is frozen. It will remain
frozen until you move the switch
back to the NORMAL position,
at which time whatever image is
currently being received through
COMPUTER IN will be displayed.

8
DUAL SYSTEM VIDEO CONVERTER
4.3 Operational Parameters
• If the computer input signal
is no longer present on
COMPUTER IN because the
computer has been turned
off or the input cable has been
disconnected, the image will
automatically “freeze” and the
LOCK indicator will go off.
• The COMPUTER output will
always display what is present
on the COMPUTER IN input,
regardless of the “display mode”
the computer may be in. If
COMPUTER IN is at 1024 x 768
resolution, COMPUTER output
will also be 1024 x 768. This is
not true of the Composite ,
S-Video, and RGBS outputs:
images in Macintosh or “super
VGA” modes beyond 640 x 480
lines will appear scrambled and
out of sync.
• For Macintosh users: The Dual
System Video Converter only
supports hi-res 640 x 480 mode.
Some Mac models boot in hi-res
640 x 480 or low-res 512 x 384
depending on the type of
attached monitor. The
Converter makes use of this
capability: If a low-res monitor
is connected to its COMPUTER
output, it will force the
Macintosh to boot in 512 x 384
mode; but if a hi-res monitor (or
no monitor) is connected, it will
force 640 x 480. If the Mac is in
low-res 512 x 384 mode, the
Composite, S-Video, and RGBS
outputs will appear scrambled
and out of sync. You might
consider purchasing the Video
Converter (Mac Compatible)
(AC076A).
LOCK UNDERSCAN FLICKER REDUCTION FREEZE IMAGE
NORMALNORMALNORMALPOWER
Receiving power
when POWER is lit;
VGA or Mac signal
is OK at input
when LOCK is lit
Image is “shrunk” in both
the horizontal and vertical
directions when switch is in
UNDERSCAN position
Anti-flicker filter is
active when switch is in
FLICKER REDUCTION
position
Image is instantly
“frozen” when switch is
in FREEZE IMAGE
position
Figure 3. The front panel of the Dual System Video Converter.

9
CHAPTER 5: What to Expect from Converted Computer Images
We have included this section to give
you some insight into what you can
and should expect computer images
to look like once they are converted
to standard video. People are some-
times surprised that computer
images converted to video do not
look as sharp and vivid as they do
on the computer monitor. Although
this may be somewhat disappointing,
it should come as no surprise.
Color TV and video monitors, and
the conventional video standards
they use (NTSC and PAL), have
been with us since the 1940s and 50s.
When high-resolution computer-
graphics standards such as VGA or
Mac II were introduced less than a
decade ago, new display technologies
had been developed to achieve
higher detail and sharper colors.
Although many design improve-
ments have been made to TV
monitors and VCRs, they are still
limited to basic technologies that
are 40 years old.
Scan converters like the Dual System
Video Converter were created to
bridge the gap between the
dissimilar standards of computer
video and conventional video
equipment. They work, but the
trade-off is that you are taking
computer images whose sharpness
and detail are clearly visible on
today’s monitors and displaying them
on TVs, or recording them on VCRs,
that do not have comparable quality.
There are a few things you can do to
get the best image possible on your
TV/monitor or recorded on video
tape. The tips that follow will all
contribute to improved quality of
your display and/or VCR recording.
• In the world of video, black, white,
and all the shades of gray are not
processed the same way as “real
colors.” TVs and VCRs process
these shades with a minimum of
distortion. When it’s possible,
consider using grayscale images,
because they’ll be much sharper
than the equivalent colored
images.
• The “Christmas Effect” occurs
with computer images created by
artists who really like the green
and red color combination.
Nothing looks worse on a TV.
Try to avoid saturated colors.
5. What to Expect from Converted
Computer Images

10
DUAL SYSTEM VIDEO CONVERTER
• Sometimes graphics look so
impressive on a computer monitor
that users assume that the process
of conversion to TV can’t possibly
make the graphics look bad.
However, what TVs will actually
show, especially if they are
displaying a video signal that was
“beat up” by a VCR recording, can
be ugly. To avoid such surprises,
connect a Converter and TV to
your computer and view your
“televised” graphics while you create
them, before you present them.
• When you make VCR recordings,
use either (1) a “Pro” or
“Broadcast” grade, name-brand
tape, or (2) an S-VHS (Super-
VHS) tape (these will play in
standard VHS machines). Also,
record using the fastest speed
(the speed corresponding to the
shortest total time per tape—2
hours on a T-120 cassette). You
will have less noise and tape jitter
in your recording.
• Almost all TVs and video monitors
overscan images, resulting in some
of the picture being “cropped”
off the edges of the picture tube.
The Converter’s UNDERSCAN
mode will shrink images to
compensate for this overscan,
which will vary in amount from
one TV or monitor to another. To
ensure that the useful parts of
your images are visible on TVs and
monitors, keep all text and other
informational content at least 5%
in from the sides, top, and bottom
of your computer monitor.
• The most annoying effect that
occurs when a computer image
is converted to video is “flicker.”
This rapid flashing of images’
brightness can appear to be
pervasive throughout the screen
or localized to one particular area.
It is most noticeable on thin
horizontal lines, particularly
on bright lines against a dark
background. It is not seen on
computer monitors because all
the horizontal lines that make
up the image are drawn on the
screen in one pass from top to
bottom, 60 or 70 times a second.
When the same image is
converted to video, a single line
will only be drawn on the screen
either 30 (NTSC) or 25 (PAL)
times a second. This rate is not
rapid enough to make your brain
register each drawing of the line
as the same continuous line, so the
line appears to flicker. The anti-
flicker filter in your Dual System
Video Converter employs an
advanced design technique to
overcome this problem with only
a very slight loss in vertical detail.

11
CHAPTER 6: Troubleshooting
This chapter lists some concerns that
commonly arise during operation
of the Dual System Video Converter,
as well as some possible causes
and remedies.
Nothing works or no computer
output.
1. Is the power supply connected
and plugged into the AC wall outlet?
Check the red POWER LED. If it’s
on, go to Step 2.
2. Is the wiring from your computer
to the Converter and from the
Converter to your video equipment
properly connected? If it is, go to
Step 3.
3. Is the computer sending out a
proper video signal? Check the
green LOCK LED. If it’s on, try
connecting your computer directly
to a monitor. If the monitor’s display
looks OK, call technical support or
your supplier for further assistance.
No video outputs.
1. Is the FREEZE IMAGE switch in
the FREEZE IMAGE position? If not,
go to Step 2.
2. Is your video equipment in the
proper mode to accept direct video
input? If it is, go to Step 3.
3. Is the computer sending out a
proper video signal? Check the
green LOCK LED. If it’s on, try
connecting your computer directly
to a monitor. If the monitor’s display
looks OK, call technical support or
your supplier for further assistance.
Some of the image is being lost off
the sides or top and bottom.
Is the UNDERSCAN switch in the
NORMAL position? If not, or if
moving it doesn’t help, then your TV
or monitor has an excessive amount
of overscan. If possible, try a
different TV or monitor. If this can’t
be done or still doesn’t help, call
technical support or your supplier
for further assistance.
6. Troubleshooting

12
DUAL SYSTEM VIDEO CONVERTER
Most of us are familiar with two
forms of TV video: (1) “RF,” which
is how broadcast and cable TV comes
into our homes, and (2) “Composite
Video,” “Baseband Video,” or just
plain “Video,” which is a single
electrical signal (made up of bright-
ness, color, and synchronizing
components) used by most VCRs.
A problem arises when your TV,
monitor, or VCR has to break either
of these signals apart to show it on
the screen or record it on tape. A
lot of processing is involved and
distortions of the image occur.
Several years ago, TV engineers
devised a simple scheme which was
not only relatively inexpensive to
implement but very effective in
reducing these distortions. It is
called “S-Video,” and can be used
with your Dual System Video
Converter.
In this TV-signal system, there
are actually two signals. The
“LUMINANCE” (“Y”) signal carries
the sync and brightness components
of the picture, while the
“CHROMINANCE” (“CHROMA”
or “C”) signal carries the color
component. By feeding these two
signals into your video equipment
separately, S-Video eliminates the
need for the equipment to do the
work of separating the signals
internally. The result is a displayed
image that has more detail and less
color distortion. If you were to
compare two otherwise identical
images, one displayed using Video
mode and the other using S-Video,
the difference in the quality of the
images would be dramatic.
Almost all of the new larger-screen
TVs that have audio/video jacks also
have an S-Video jack just like the one
on the rear of your Converter. If it is
available, use it! You will see a
difference.
Appendix A: S-Video, the Improved
Quality Video Standard

13
APPENDIX B: Connector Pinouts
POWER
Center +5 VDC In
Outer Ground
VIDEO IN (“COMPUTER IN”)
VGA Macintosh
1 Red Red
2 Green Green
3 Blue Blue
4 N/C ID Bit Lo-Res Out
5 Ground Ground
6 Red Ground Red Ground
7 Green Ground Green Ground
8 Blue Ground Blue Ground
10 Ground Ground
11 Ground (ID bit 0) Ground
13 H-Sync In Comp Sync In
14 V-Sync In V-Sync In
15 ID bit 3 H-Sync In
Appendix B: Connector Pinouts

14
DUAL SYSTEM VIDEO CONVERTER
COMPUTER OUTPUT
VGA Macintosh
1 Red Red
2 Green Green
3 Blue Blue
5 Ground Ground
6 Red Ground Red Ground
7 Green Ground Green Ground
8 Blue Ground Blue Ground
9 N/C ID Bit Lo-Res In
10 Ground Ground
12 ID bit 1 N/C
13 H-Sync Out Comp Sync Out
14 V-Sync Out V-Sync Out
15 ID bit 3 H-Sync Out
COMPOSITE VIDEO OUTPUT
(“VIDEO”)
Center Video Out
Outer Video Ground
S-VIDEO OUTPUT
1 Ground
2 Ground
3 Luminance
4 Chrominance
RGBS OUTPUT
(“RGB/EXPANSION”)
1 Ground
2 Ground
3 Red
5 Green
7 Blue
15 Composite Sync

1000 Park Drive • Lawrence, PA 15055-1018 • 724-746-5500 • Fax [phone]
© Copyright 1993. Black Box Corporation. All rights reserved.