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FAQ's:
Serial Cables: Controlling a Videodisc Player |
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ALERT!
This section of the FAQ's is presented more for its historical significance
than actual technical support. Videodisc players are difficult to find
these days. As well, serial ports have been replaced by USB and Firewire
connections on most contemporary computers. Lastly, the information here
is relevant for Macintosh computers running OS System
8.6 or earlier and for Windows computers running OS Windows 98 or earlier.
The protocols and drivers used to control the playback of videodiscs simply
don't function on the newer computers and operating systems.
Now that
you are forewarned, please proceed.
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THE
VIDEODISC PLAYER IS NOT RESPONDING: Now What?
Linking a
videodisc player with the computer is often the most frustrating part
of using an interactive program. There are many "gotchas." Try using one
of the following solutions:
- Make sure
the videodisc player is turned on and has a disc in it. Try turning
the player OFF and then ON again and wait until the disc is spinning
at a constant rate (the videodisc will either frame stop on the first
frame of the disc, or you'll see images flying by on the video monitor).
Also, make sure that the disc is inserted with the correct side up.
- Check
that the serial cable is securely inserted and make sure that it is
in the preferred port on your computer. For heavens sake, don't be lazy...be
sure you tightly SCREW the cable plug into both the videodisc player
and computer port (if possible). A wobbly plug has been the cause of
many hours of troubleshooting.
- Make sure
that the baud rate setting on the videodisc player is correct. For example,
the Pioneer 4200 only uses a baud rate of 1200 or 4800. If the software/computer
baud rate setting says one bit rate and the videodisc player is set
to another...nothing happens.
- Quit your
program and turn everything off (the videodisc player, the television,
the computer, and any hard drives). Then restart everything making sure
all peripheral devices, particularly the videodisc, are powered up and
fully running before the computer is turned on. This procedure will
often scare away any gremlins.
- If there
are strange "clunking" noises, searches take several seconds or are
never completed, commands work intermittently, or other odd things happen,
you may have a problem with your videodisc or player. If you have any
other videodiscs, try putting one into the player and testing it. Your
problem disc may be warped. Be careful to store your discs vertically
and away from sources of heat. They are not indestructible.
- If you
change the Dip Switches for baud rate on your videodisc player while
it is POWERED ON and connected to your computer, you must turn everything
OFF and start over in order to reset the new parameters. You can't change
a videodisc player's baud rate on-the-fly and expect your computer to
understand what you're doing.
- Beware
of cheap, cruddy cables. Connectors should be high quality and tight
fitting, especially at 9600 baud. You can spend hours trouble shooting
this variable!! Note that standard PRINTER cables may have the right
connectors, but they won't work with a videodisc player. The PIN assignments
are different.
- Some older
players have a lock down screw that is tightened for shipping or moving
the player (most newer models don't have such a manual lock down screw).
Be sure this is loosened (see your owner's manual for details).
- Do not
set a heavy TV monitor on top of the videodisc player. It makes for
a tidy look, but wreaks havoc with the disc mechanisms directly under
the player's thin metal housing. Over time you may experience a total
failure from your videodisc player, or you may begin to see some very
interesting display effects on your TV monitor. Avoid setting anything
on top of your videodisc player. Also, keep the ventilation slots free
and clear.
- Be sure
to check that the video and audio cables feeding your television monitor
are securely connected and that the monitor is set to the right input,
i.e., Input 1, Input 2, etc.; it varies from TV to TV. Some videodisc
players offer an RF feed to your TV like a VCR does. In such cases,
you would tune the TV (if it has a tuner) to Channel 2 or 3 to hear
and see the videodisc signals.
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MACINTOSH
COMPUTER: Advisories & Peculiarities
- OLDER
MACINTOSH AV MODEL ADVISORY:
For those of you using such machines as the 840 AV, the Centris AV,
or other AV models, the modem serial port is a specialized "GeoPort"
for communications links. There is a System Extension governing the
GeoPort. Drag this extension to an obscure folder somewhere outside
of the System folder, reboot, and your serial port should behave like
an old, run-of-the-mill modem port. For more complete information, check
your computer's user manual.
- OLDER
POWERBOOK ADVISORY:
For those of you using a Macintosh PowerBook (prior to about 1997) hooked
to a videodisc player through your modem/printer port, be aware that
the default setting is for the PowerBook to use its internal modem (if
so equipped). This won't work at all for running an external serially-controlled
device such as a videodisc player. Use the Control Panel called POWERBOOK
SETUP to switch from "internal" to "external" modem. Some newer models
offer you a different choice in this SETUP control panel, namely either
"compatible" or "normal." The "normal" option is for using an external
modem or other serial device (such as the videodisc player). For DUO
230 and PowerBook 160 models, remove the MODEM TOOL EXTENSION. Also
the COMMTOOLBOX can sometimes conflict with the serial port communications
with the videodisc.
- QUICKDRAW
GX ADVISORY:
QuickDraw GX was part of System 7.5; it handled output through the Printer
Port differently than in the good old days. We strongly advise System
7.5 users to connect their videodisc players through their modem port
if they have installed QuickDraw GX. If you haven't installed QuickDraw
GX...no problem. If you have, you can temporarily disable it by using
the Extension Manager Control Panel and deselecting the GX extension.
Be sure to save this setting. You won't be able to use any QuickDraw
GX features until you turn the extension back on again. However, your
serial port will be able to control an external serial device, such
as the videodisc player. The other option is to drag the QuickDraw GX
extension to some obscure folder outside of the System Folder and Restart
the computer.
- ADVISORY
ON CONFLICTS:
Scour your Control Panels and Extensions folders for anything related
to modems and faxes (even EtherTalk in some cases). Drag these offending
items to another obscure folder somewhere out of the System folder.
Basically, anything present in your computer system which competes
for control of the serial ports can be a source of trouble. We found
this to be true for newer G3 computers with System 8. A lot of fax and
modem extensions come preloaded. Purge them from the System and reboot.
This proved to be the magic pill for one of our users.
- CORRUPTED
PREFERENCES FILE:
Previous unsuccessful attempts to load and use the Slice of Life FileMaker
Pro Index with the videodisc may have corrupted the Preferences
file. In the System Folder, find the Preferences Folder. In that folder
will be a Voyager Videodisc Drivers Preferences document. Drag
it to the trash. A new one will be created for you automatically later
on.
- ZAP THE
PRAM:
Restart your computer...but ZAP THE PRAM in the process. The Parameter
RAM or PRAM in a Macintosh remembers control panel settings and what
is connected to the modem and printer ports. By zapping the PRAM, you
purge any old incompatible settings. On restart, hold down the Option,
Command (Apple Key), P and R keys all together. Get
a friend to help if you run out of fingers. Let your computer go through
its restart cycle about 3 times (that's 3 musical start up chimes).
- REBUILD
THE DESKTOP:
It never hurts to rebuild your Macintosh Desktop. On bootup, hold down
the Command and Option Keys down until a
dialog box asks if you wish to rebuild your hard drive's desktop. Say
YES.
- DEACTIVATE
APPLETALK:
Once the computer is restarted, open the Chooser and make sure that
AppleTalk is INACTIVE. Even if the radio button for this
selection is already selected, select it once again just to be sure.
Deactivating AppleTalk, and thus any chatter with networks or other
computers, has often solved communication problems.
- PIONEER
4400 PLAYERS WITH BAD VOLTAGE:
There are some Pioneer 4400 model videodisc players that were unfortunately
manufactured with a slightly different voltage applied to one of the
pins on the deck's serial control port that connects to your computer.
The problem you will experience is a total shutdown of your computer
when you try to engage communication between the computer and the videodisc
player. Specifically, in troubleshooting this problem it was discovered
that a Pioneer 4400 player put out 7.5 volts on the RXD line to a Power
Macintosh 8500 instead of the 5 volts as it should. Inserting a 1K ohm
resistor in the RXD line of the Pioneer CC-04 cable fixed this issue.
Pioneer was aware that certain Pioneer 4400 players put out too much
voltage. This was fixed in a revision to the player after 1994. The
Pioneer player we investigated was manufactured in August of 1992, with
a serial number starting with MH390. Thanks to Peter Durnin of The Voyager
Company (212.219.2522 ) for supplying us with this solution.
- INVOKE
THE POWER OF THE UTAH RUBBER CHICKEN:
If all else fails, wave one of the Utah
Rubber Chicken over your computer setup. It just may purge the demons
of stupidity from your system.
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WINDOWS
COMPUTER: Advisories & Peculiarities
- THE OEMSETUP.INF
FILE:
When installing a videodisc driver on your Windows computer, be sure
you have on hand the OEMSETUP.INF file which we have supplied with your
FileMaker Pro Index to the Slice of Life or Slice of Brain. Without
this file, you cannot successfully install a new videodisc driver and
communicate with your player. The file called OEMSETUP.INF should
never be deleted.
- FMLASER.EXE:
When using our FileMaker Pro Indexes with a videodisc player, the FMLASER.EXE
file must be present and preferably at the same directory level as the
Index file. Without FMLASER.EXE, the videodisc cannot communicate properly
with your computer.
- ONE VIDEODISC
DRIVER AT A TIME PLEASE:
Our tryouts of the videodisc drivers show that only one driver can be
installed and setup in your Windows operating system at any one time.
If you need to change the driver for your system because you have changed
the videodisc player type/model, please follow the RULE OF THE THREE
R'S, that is, (1) REMOVE, (2) RESTART, (3) REINSTALL. You will need
to Remove the original driver, Restart Windows (not your computer),
and then Reinstall the appropriate new driver. If you don't follow the
RULE OF THE THREE R'S, you'll be running in needless circles.
- COM PORT
SETTINGS:
When setting the Communication Port Properties for either COM1/3 or
COM2/4 on your computer, you will be asked to confirm 5 variables. The
first one, BITS PER SECOND, refers to the baud rate setting or the speed
of communication between your computer and the videodisc player. From
the pull down list, select whichever baud rate matches that set for
your particular model of videodisc player. The speed of 4800 and 9600
are very common, but be sure to confirm what your disc player is set
at. Don't guess, because it likely is incorrect.
The other four settings must be set as follows: DATA BITS = 8, PARITY
= none, STOP BITS = 1, and FLOW CONTROL = Xon/Xoff. Note that you may
also want to confirm that the videodisc player's PARITY setting is also
set to NONE. Some players, particularly the Pioneer models with "on
screen" menu adjustments, give you this option. The producers spent
several hours trouble shooting a stubborn videodisc-PC connection at
one conference only to finally discover that someone had reset the laserdisc's
PARITY setting to something non-standard. Be vigilant and thorough.
- PIONEER
4400 PLAYERS WITH BAD VOLTAGE:
There are some Pioneer 4400 model videodisc players that were unfortunately
manufactured with a slightly different voltage applied to one of the
pins on the deck's serial control port that connects to your computer.
The problem you will experience is a total shutdown of your computer
when you try to engage communication between the computer and the videodisc
player. Specifically, in troubleshooting this problem it was discovered
that a Pioneer 4400 player put out 7.5 volts on the RXD line to a commputer
instead of the 5 volts as it should. Inserting a 1K ohm resistor in
the RXD line of the Pioneer CC-04 cable fixed this issue. Pioneer was
aware that certain Pioneer 4400 players put out too much voltage. This
was fixed in a revision to the player after 1994. The Pioneer player
we investigated was manufactured in August of 1992, with a serial number
starting with MH390. Thanks to Peter Durnin of The Voyager Company (212.219.2522
) for supplying us with this solution.
- INVOKE
THE POWER OF THE UTAH RUBBER CHICKEN:
If all else fails, wave one of the Utah
Rubber Chicken over your computer setup. It just may purge the demons
of stupidity from your system.
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INFO
ABOUT RS-232 SERIAL PORTS:
The following
is taken from the University of Utah Computer Center Newsletter article
by Keith Chojnacki:
"RS-232,
the Non-Standard"
There are
many "standards" in the world of electronics. Some are used as defined,
some are confused as defined, and some are confused as used. The famed
RS-232-C Serial standard is confused as used. The problem starts with
the fact that the standard defined for RS-232-C is a pin usage outline
and voltage level reference for transmit and receive conditions. This
leaves the user to determine how the pinouts are to be used at the connector
or in the software. Even if the defined pinouts are used, the software
driving the hardware might not use the pins as defined. Results are
usually cabling and software incompatibilities.
No matter
what computers or configurations are used, someone will have to struggle
setting up cables between the two machines and make them behave long
enough to talk to each other intelligently. There are several pinouts
and plug sizes to choose from. The 25 pin "D-shell" plug is the defacto
standard for most current connections. The small 9 pin "D-shell" plug
used on newer machines is a better use of space with fewer lines. The
newest plug is the tiny "DIN-8" found on most Macintosh computers. The
tiny DIN-8 leaves no room for easy cable making. The plugs are hard
to find and harder still to solder up. Sometimes an adapter cable is
easier to purchase than make. This leads to checking the adapter to
make sure the wires connect to the proper pins. To do this, get a beeping
continuity meter and "ohm out" the cable pin for pin, at each end, to
check compatibility for your needs.
Adapters
are, at best, a stop gap tool to help make a good cable; but, if you
plug one device into many other computers you may as well get a stock
of different types, you'll need them. A recent cabling problem comes
to mind as an example. The cable pinouts for the two computers were
found and a cable was assembled. The first attempts to communicate between
machines were partially successful. After some pin swapping, data was
going full bore one way only. Maybe the software needed changing! Two
or three telecom programs later, software was found that allowed the
right kinds of settings to be made. Next, the trans-computer cabling
was attached to a break-out box where the signal lines could be seen
as the data went from machine to machine. Now data could be shipped
both ways, but not in proper order. Finally, the two computers were
tamed down and began talking like old friends with a minimum of ground
rules for trading data.
The short
point of this story is that RS-232-C connection didn't appear to be
the major problem. The software, along with a minor cable change, and
many trials at understanding the software operations, were the main
problem. But, the software used it's own definition of the control lines,
a non-standard!
If you
need to have two computers communicate for uploading/downloading of
data, the following pinout definitions will help get the cables made.
Also, check out the ANSI standard on RS-232-C or read one of many good
serial books for programmers or hardware designers.
To summarize:
The novice should purchase a commercially available cable! The cable problems
that you will have are part of the nature of the RS-232 connection.
ALERT! Such serial cables are difficult to find these days. Please refer
to the next section: Pin-Out Configurations for Serial Cables:
The Cable Jungle.
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PIN-OUT
CONFIGURATIONS FOR SERIAL CABLES:
The Cable Jungle
The Slice
of Life Producers oftened referred to the challenge of matching the right
serial control cable from a Macintosh or Windows-based computer to various
models of videodisc players as THE CABLE JUNGLE. Each computer and each
videodisc player model required a different cable. These cables were not
just your run-of-the-mill serial cables with MINI-DIN 8, DB-15, and DB-25
connectors and pin configurations. Each cable was unique. When demonstrating
Slice of Life videodiscs, the producers always traveled with a satchel
full of different cables to satisfy any scenario or situation.
Most of the
information contained in this section is historical in nature. Good luck
trying to find a serial port on a contemporary computer! Good luck trying
to locate a videodisc player with a serial port!
Because we
were interested in preserving the legacy of information about videodiscs
and their interactive environments, we decided to pull from our library
of documentation everything we could find about the pin-out configurations
for serial cables that would control videodisc playback. The documentation
is provided in Adobe PDF files, created from hard copy originals of materials
archived in our offices. We apologize if the quality of the documents
may be lacking; many pages were faxes and photocopies of photocopies.
The list
below identifies each document and includes a brief paragraph about its
contents. Sorry if it appears as a hodgepodge of data...but some information
is better than none at all.
Document 1 [soon to be posted]
[Description]
Document 2 [soon to be posted]
[Description]
Document 3 [soon to be posted]
[Description]
Document 4 [soon to be posted]
[Description]
Document 5 [soon to be posted]
[Description]
Document 6 [soon to be posted]
[Description]
Document 7 [soon to be posted]
[Description]
Document 8 [soon to be posted]
[Description]
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