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This software is provided as a service, and is not for sale for resale. Apple makes no warranty or representation, either express or implied, with respect to this software and its quality, performance, merchantability, or fitness for a particular purpose. In no event will Apple be liable for direct, indirect, special, incidental, or consequential damages resulting from any defect in the software or its documentation. No person is authorized to make any warranty on this software.
This unsupported utility is a "Monitors CDEV Extension" which may be of assistance in obtaining interlaced, RS170-compatible video output signals from a Macintosh II-class machine equipped with the Macintosh II Video Card. It may support 1,2,4, and 8 bits-per-pixel interlaced video. In also may provide an optional "no flicker mode" for the 1 bit-per-pixel mode. This mode eliminates the flickering caused by thin horizontal lines (like the racing stripes at the tops of windows) that occurs when Macintosh video is transferred to video tape.
Audience:
This video utility allows developers and video-knowledgeable users to obtain medium quality video output at extremely low cost. This is not intended for the unsophisticated user. If you don't know how to make a video cable, this software is not for you!
Pluses:
+ Supports 1 to 8 bits per pixel RS170 video output
+ This type of video can be video-taped
+ Flicker filter improves image quality in 1 bit per pixel mode.
Minuses:
- Requires a special cable.
- Flicker filter slows the computer down 20% to 40%.
- Flicker filter uses about 48K of RAM
- Not 100% broadcast-quality RS170 signal.
Hardware Required:
Ñ A Macintosh II-class Macintosh computer.
Ñ An Apple-brand 640 x 480 x 4 or 8 bit Macintosh II Video Card.
Ñ A special cable (you make) to connect the video card to your video equipment.
Software Required:
Ñ System 6.0.3 (or higher).
Ñ The Monitors 4.0 Control Panel device (available with 32-Bit QuickDraw).
Ñ The General file accompanying 32-Bit QuickDraw
Ñ 32-Bit QuickDraw
About the Cable:
You will need a special cable to connect a RS170-compatible monitor (or VCR) to your Macintosh. One side must plug into the Apple Macintosh II video card. It must have a 15-pin male DB15 connector. The other side must plug into your video equipment. Pin 5 of the DB15 connector contains the RS170-compatible monochrome video signal. Pin 6 is the shielding ground for this signal. Typically you would connect pin 5 to the central wire of your video cable, and connect pin 6 to the shielding braid.
WARNING: it is possible to damage your video equipment and/or your Macintosh II by using an improperly constructed cable. If you are not familiar with video equipment, you should not try to make a special cable!
About RS170:
RS170 is the name of the interlaced 60hz video signal standard used for broadcast video in America. It can be recorded using the Video In jacks of most video tape recorders. The Macintosh II Video Card can generate a signal which is very close to the exact specifications of the RS170 standard. Close enough that it can be displayed on most RS170 monitors, recorded on most RS170 video tape recorders, etc.. Unfortunately, the minor deviations from the exact standard will cause problems with some video equipment.
The video signal produced by this utility might be incompatible with your video equipment. If this is so, you might try adjusting your video equipment's controls to see if you can get it to lock onto the signal. If you have a time-base corrector available, try using it to clean up the signal.
Otherwise, you might consider purchasing one of the commercially available, high-quality RS170-compatible video boards which are available for the Macintosh II.
How to install the utility:
1) Make sure you have an Apple Macintosh II Video Card (640x480, 4 or 8 bits)
plugged into any slot of your Mac II.
2) Drag the utility file into your System 6.0.3 (or higher) folder that also contains
the 32-Bit QuickDraw package:
Ñ 32-Bit QuickDraw
Ñ Monitors (version 4.0)
Ñ General
3) Reboot your Mac by choosing "Restart" from the "Special" menu.
4) As your Mac reboots you will see the video utility icon (a Mac II with a TV and a
VCR on it), appear in the lower left corner of your screen. A black X will be
super-imposed on top of the icon to indicate that the video utility is currently
inactive.
How to turn on RS170 mode:
1) Bring up the Monitors 4.0 cdev of the Control Panel. Click on the monitor
you want to display at RS170-video rates. Set it to the color level you want.
2) Click on the "Options" button.
At the bottom of the Options dialog box you will see two radio buttons
and a check box. Click on the "Interlaced" button to select the
interlaced mode.
3) Choose "OK".
4) Click on the close box to dismiss the Control Panel.
5) Turn off your computer by choosing Shut Down from the Special menu.
6) Once the computer is off, disconnect your regular monitor and connect
your RS170 video device. You will need a special cable to connect the
RS170 monitor (or VCR) to your Macintosh. Pin 5 has the monochrome
RS170 signal, pin 6 is the ground.
7) Turn on both the RS170 device and your Mac II computer.
8) For the first several seconds (20 to 60) of the boot sequence, the
Mac II will be producing 67-hz high-resolution video, which will show
up as a pattern of diagonal lines on the RS170 monitor.
9) Once the Mac II loads in and executes the utility, the Mac II
will produce RS170-compatible video. The diagonal lines will clear
and you will see the Macintosh Desktop. On some monitors you might
have to adjust the horizontal hold slightly to get the signal to lock in.
Trouble Shooting:
If this doesn't work, you can trouble shoot the problem by reconnecting your normal Mac monitor and rebooting. Watch for the video utility's icon ╤ a Mac II with a TV and a VCR on top ╤ to come up. If it comes up with an X on top of it, it wasn't able to install itself. Some reasons for the X might be:
Ñ You haven't selected a video card. (So follow steps 1-4 above).
Ñ You moved the video card from one slot to another. (So repeat steps 1-4).
Ñ The card you selected isn't an Apple brand 640 x 480 video card.
Ñ There isn't enough RAM in the system heap (This utility uses up to 48K
of the System Heap .)
If it comes up without an X, then the video utility has installed itself. Your video screen should switch to RS170 mode just before the utility icon appears. If it stays in normal Macintosh video mode, some of the reasons might be:
Ñ You selected another screen besides the one you're looking at. (This could
happen if you had more than one video card installed at once.)
Ñ On an old card, you selected "Normal" rather than "Interlaced" video mode.
NOTE: You can always prevent the video utility from installing itself by rebooting your Macintosh while holding down the mouse button. Keep holding down the button until the video utility's icon appears. It will have an X drawn over it, to signify that it has not installed itself.
About the flicker filter:
The flicker filter reduces flicker in a RS170 video image of a Macintosh screen. Flicker is caused by thin horizontal lines. These lines show up in alternate frames of the RS170 signal, which causes them to flash on and off at 30hz. Flicker is eliminated through software which looks for thin horizontal lines and compensates for them. This scanning and compensating process takes 20 to 40 % of the computer's time, depending upon how quickly the screen image is changing. The less the image changes the less work the flicker filter has to do.
How to turn on the flicker filter:
1) Follow the steps above to make your system work at RS170 rates.
2) Bring up the Monitors Control Panel device. Click on the monitor
you are using to produce RS170-compatible video.
3) Set the screen depth to "Black & White".
4) Click on the "Options" button.
At the bottom of the Options dialog
you will see two radio buttons and a check box. Click on the
"Interlaced" button to select the interlaced mode. Click the
"Flicker filter" check box to turn on filtering.
5) Choose "OK".
6) Click on the close box to dismiss the Control Panel.
7) Reboot your computer by choosing "Restart" from the "Special" menu.
8) Once the video utility icon reappears, the flicker filter will be working.
How to turn off the flicker filter:
1) Bring up the Monitors Control Panel device. Click on the monitor
you are using to produce RS170-compatible flicker free video.
2) Click on the "Options" button. You will get the Options dialog. Notice that the "Flicker
filter" check box is checked.
3) Click on the "Flicker filter" check box to turn off the flicker filter. As you do this you
will see the filtered screen start to flicker. If you wish to compare the quality of unfiltered
to filtered video, you can continue clicking on the check box. Successive clicks will toggle
the filtering on and off.
4) Once the "Flicker filter" check box is unchecked, click on the "OK" button.
5) Click on the Control Panel's close box.
6) Choose Restart from the Special menu of the Finder.
How to change the size and mode of the interlaced screen:
This video utility program supports a variety of screen sizes and video modes. Unfortunately, selecting the screen size and video mode you want is not always possible. The screen sizes available to you depend upon the video mode you wish to use:
You are limited to the plain screen size of 640 x 480, except when using the flicker filter. When the flicker filter is active, your screen size is 512 x 342, which is the size of the original Mac Plus screen. This smaller size was chosen to make it easy to video-tape HyperCard stacks. The smaller size brings all of the screen into the "safe title" area of the video signal. This is the area which is legible on almost every kind of video monitor.
How to remove the video utility:
1) Drag the video utility out of the system folder.
2) Choose Shutdown from the Special menu.
3) Connect your normal 67-hz monitor to the Mac II.
4) Restart your Mac.
HyperCard Hints:
When using the flicker filter to video-tape a HyperCard stack, you might want to use a line like:
set loc of card window to 0,0
It will position the card window so that it exactly fills the screen.
Bugs and/or Misfeatures:
Ñ The utility is believed to be incompatible with Fifth Generation Systems'
Suitcase¬ II 1.2.
Ñ The flicker filter mode is incompatible with most screen savers.
For best results, disable your screen savers while using the flicker filter.
Ñ There are a few minor pitfalls associated with using this video utility
with multiple monitors. When you have multiple monitors and have the
flicker filter turned on, you may find
that, upon, rebooting, some monitors are inaccessible. This is because the
video utility has reduced the size of the filtered screen, creating a gap in
the Desktop region which the mouse can't leap over.
If this happens, do the following:
1) Choose the Control Panel
2) Choose the Monitors Control Panel Device
3) Use the mouse to reposition the monitors so that the "flicker free"
monitor is below and/or to the right of all of the other monitors.
4) Click on the Control Panel's close box.
5) Choose "Restart" from the "Special" menu of the Finder.
Credits:
This utility and its documentation was written by Jack Palevich.
The flicker filter was originally written by Steve Perlman (in 1985!).
