Conference hydra::amiga_v1

    If you are only interested in titling, I'd go with the 1000 because
    it has color composite output that yopu can connect directly to
    you VCR. A1000s are no longer manufactured, and are difficult to
    expand. A500s are difficult to expand too without and external box
    of some sort. The A2000 on the other hand can be expanded internally.
    There are a number of companies that have internal boards on the
    market (or under development) that will support your video habit.
    
    The flicker is merely what you will inherently get when using 640x400
    interlace mode on the Amiga with a standard monitor. The flicker
    is reduced when using a long persistence monitor. It is completely
    eliminated on the A2000 through the use of Flicker Fixer, an internally
    mounted (inserts in the video socket) board that works with just
    about any Multiscan-type monitor in 640x400 interlace mode.
    
    Paul
   

    Color composite convertors for the a500 are available for ca. $35
    People do expand the A500 with external boxes from other manufacturesr
    Tom

For your purposes, flicker (really the interlaced signal which sometimes
causes it) is good!

A standard television signal is made up of two interlaced "fields."
A frame in the picture is displayed by displaying the first field
(the even numbered scan lines), repositioning the beam to the top
of the display, and then displaying the second field (the odd numbered
scan lines).  This is called "interlace."

Back in ye olden days when the current television standard was invented,
interlace allowed the vertical resolution to be doubled without doubling
the bandwidth of the signal.  Of course, the disadvantage was that it
reduced the frame update rate from 60 frames a second to 30 frames a second.

Interlace can cause flicker.  The phosphors in the picture tube only
hold an image for a short period of time.  As the second field is being
drawn, the first field is fading away.  If the frame being displayed is
very sharp an full of contrast, the effect can be quite noticeable.  If
on the other hand the frame is low contrast, the picture will seem quite
solid.

A typical frame from a TV broadcast or a digitized picture from a computer
usually will not flicker.  There is a wide range of colors, smooth shade
transitions, and the edges of objects are slightly blurry.  In contrast,
text and some pictures produced with "paint" programs do flicker.  The
frame consists of highly contrasting colors (white on black is very bad!)
and razor sharp edges.  Under such conditions, the images seems to jitter.

The Amiga is capable of doing interlace.  The North American Amigas support
two standard vertical resolutions: 200 lines or (in interlace mode) 400
scan lines.  Unless you have really great eyes, or a FlickerFixer, or
a long persistence monitor, 200 scan lines is the only practical
resolution for text applications (although nothing prevents you from using
400 scan line mode).  Four hundred scan line mode is practical only for
graphics or (ta-da) desktop video.

The 400 scan line mode (interlace) is a requirement for a desktop video
machine.  It produces a standard television signal.  For titling and
like, interlace flicker is not too much of a problem.  First, titles
are usually doing using a large font (you don't want 25 lines of 80
characters of titles!).  Second, TV is watched from several feet away.

If you must, most VCRs will record a 200 scan line non-interlaced signal.
So you can record non-interlaced graphics.

A related subject you may hear about is "overscan."  Using the standard
horizontal and vertical resolutions (even in interlace) on the Amiga
results in a picture with a border around it.  The Amiga hardware is
capable of higher resolutions which will eliminate this border.  Almost
all of the current Amiga video programs support overscan.

Overscan isn't much of an issue for titling:  a genlocked image always
fills the video screen from edge to edge.  Doing titling without 
overscan would just mean the Amiga graphics overlaying the image
could not go from screen edge to screen edge.  Since titles are usually
centered, overscan isn't very important.  However, if you are making
a computer animation to be video taped, overscan is nice.

    Flicker can also be eliminated by using the MicroWay deinterlacing
    board.  This is a short card that attaches to the video bus and
    reads the Amiga's video buffer(s) into a single buffer, to which
    you attach a multi-sync monitor.  I've finally seen this in action
    and it is GREAT!  The problem with the Flicker Fixer is that you
    don't get as many colors.  The MicroWay board does not suffer from
    this.  

    
    Huh?  I think you (or I ) may be confused.  The MicroWay board IS
    the FlickerFixer.  I have one in my A2000, and it in no way limits
    the number of colors viewable or the pallette size.
    
    It's merely combines two interlaced frames and displays then at
    a 60 Hz verticle refresh rate and a 31.5 KHz horizontal scan rate.
    In non-interlaced modes, the board performs scan-doubling, which
    fills in the gaps beteen characters (similar to the SETLACE command  
                                              
    The MicroWay board has it's own 9 pin sub-miniature D connector,
    so your standard Amiga RGB at 15.75 KHz is still available for video
    work, as is your composite out.
    
    Ed.

I use interlace all the time. It's really a shame standard Amiga's have to
"flicker". Interlace makes all the difference in the world by giving you much
more screen real estate (twice as much!).

The flicker can be HORRIBLE or just barely noticeable. It's all a matter of:


	1. Choosing the "right" colors to provide a low contrast screen
	2. Adjusting the brightness and contrast controls of your monitor.


I have a standard A500 with the 1080 monitor. I use the standard Workbench
colors (Used to be shades of grey, but I *like* color). The trick in my
case was to set brightness to the center "detented" position and lower the 
contrast until the flicker almost dissappears all together. Then bring
up the brightness a bit to help compensate for the lower overall intensity
that reducing the contrast caused.


I use it like this constantly and would not even concider switching back to
non-interlaced mode!! The benifits just far outweigh the "tuneable flicker"


John

I am seriously considering getting a flicker fixed and a multi-sync monitor,
and just have a couple of questions.

Is the Microway flicker fixer the only device of its type currently available?
Has anyone heard of anyone else working on such a device for the Amiga?
I have heard that using the flicker fixer during animation has some wierd
side effects. What are they, and are they that noticable?

There has been some discussion on multi-sync monitors elsewhere in this file,
but I'm interested in how many out there have flicker fixers and multi-sync
monitors, and what type on monitor they have and how they like it. These
monitors are expensive, and since the best prices seem to be mail order,
I might end up ordering one sight unseen and want to make sure I don't
make a big mistake. Any suggestions?

Thanks,
Frank

    Three questions: 1. how much is the flicker fixer
    2. How much is a good color monitor that will work with it.
    3. Can all of this work in the A1000?
    
     - chris
    

    Is the VR241 a multi sync monitor ?
    Will flicker fixer work with a early A2000 (i.e. not a B2000) ?
    
    Martin

    
    I have a FlickerFixer in my A2000.  I also am using a Princeton
    Ultrasync monitor.  It's a 12" monitor, which is OK for me.  Mail
    order prices are just over $500, so they're not too expensive.
    
    Currently, Microway is the only vendor for the deinterlacer.  I've
    heard that others are working on similar products.  (Seems like
    there's a good market for it).  Microway is also working on an
    A500/A1000 version that works in every mode except HAM, since these
    machines don't have a convenient location to pick off the necessary
    12 color bits, like the video slot in the A2000.
    
    I think you'll see a trend to put this type of hardware into the
    monitor.  The Moniterm 19" display for the Amiga does this.
    
    As far as animation goes, yes, there is a noticible blurring when
    moving the mouse diagonally quickly.  It's not an annoyance to me.  In
    fact, it's no more annoying than the cursor on the Mac or Atari, which
    seem to flicker a bit when moved  (these systems don't use a hardware
    sprite for the cursor, hence the CPU must redraw the entire cursor
    every frame).  I haven't found any games that become irritating or even
    noticibly blurred due to this effect.  In fact StarGlider II looks just
    fantastic, and it has incredibly fast graphics.
    
    Whether or not you buy a FlickerFixer depends on how badly you want
    to use 400 line mode for everyday work.  However, I would recommend
    a multisync monitor.  Why?  Because it will work with current and
    future Amiga chipsets.  The current 1080 monitor will not support
    the new 400 line non-interlaced mode.  This mode will require a
    monitor that supports horizontal scan rates of 31.5 KHz.
    
    Ed.