[comp.sys.amiga.hardware] FlickerFixer owners

walker@sas.UUCP (Doug Walker) (04/09/90)

In article <4626@jhunix.HCF.JHU.EDU> barrett@jhunix.HCF.JHU.EDU (Dan Barrett) writes:
>
>	I don't quite understand some things about the FlickerFixer by
>Microway.  Maybe some owners could help me?
>
>(1)	When the Amiga is NOT using interlace mode, I assume that the
>	FlickerFixer sits there doing absolutely nothing.  Is this
>	true?
>
No.  The flickerFixer is still deinterlacing the display and putting out
double the normal scan rate.  The difference is visible in that the raster
lines normally visible (dark horizontal lines between pixels) are removed.

>(2)	There was some discussion long ago that the FlickerFixer
>	makes some animated objects (like the mouse pointer, sprites, etc.)
>	look different.  I can't remember the details.  I think someone
>	said that a moving object appeared as several objects.  Am I
>	misled?
The way the NTSC standard works, all odd-numbered scan lines are drawn first,
then the beam goes back to the top and draws all even-numbered scan lines.
Flicker creeps in because pixels are slightly brighter immediately after being
drawn.  Thus, if we draw line 20 of the display, the pixels on line 20 will be
brighter than the ones on lines 19 and 21.  1/60 of a second later, the ones
on 19 and 21 will be brighter than 20.  This is perceived as flicker by your
eye.

The flickerFixer eliminates this problem by 'remembering' the odd scan lines 
just drawn while the even scan lines are being drawn, and modifying the RGB
output to show ALL lines, even and odd.  THis means twice as much information
is going out from the fF than the normal Amiga.  After the even scan lines are
drawn, it 'remembers' the even ones while the odd ones are redrawn.

The way this affects animation should be apparent.  Since fF is mixing lines
from 1/60 of a second ago with lines from now, fast-moving animated objects
will appear to split up into two half-intensity objects, one slightly behind
the other one.  The one in the lead is the actual position of the object, the
one behind is the position of the object 1/60 of a second ago.

This sounds bad, but it's not really that noticeable.  Most animated objects
don't move very far in 1/60 of a second.  You can make it happen with the
mouse pointer by moving it around very quickly, but that's the only time I've
noticed it.  (I don't play many games on my 2000, though).

>(3)	Any complaints about your FF?  Do you like it?
I could not work on my Amiga without it, now.  It is the single most important
piece of expansion hardware I own.  I am one extremely sold customer.  It is
also quite easy to install and use, and I've never heard of a hardware problem 
with it.  You do need to be careful about using it with a genlock, however -
it requires an extra ($75) piece of hardware to work correctly.


  *****
=*|_o_o|\\=====Doug Walker, Software Distiller====== BBS: (919)382-8265 =
 *|. o.| ||
  | o  |//     For all you do, this bug's for you!
  ====== 
usenet: ...mcnc!rti!sas!walker   plink: dwalker  bix: djwalker 

blgardne@esunix.UUCP (Blaine Gardner) (04/12/90)

From article <4668@jhunix.HCF.JHU.EDU>, by barrett@jhunix.HCF.JHU.EDU (Dan Barrett):
> 	Is it possible, and safe, to hook up some kind of A/B switchbox
> like this?
> 
>                  FlickerFixer video out -----
>                                              \
>                                               X---------> monitor
>                                              /
>                  Original video port out ----
> 
> Would it be safe to "flip the switch" while the monitor and computer are
> on?  How about with computer on, monitor off?

I've done exactly this, based on another netter's suggestion. I bought a
DB-9 switchbox for about $15-20, and just plugged in the cables. You
will need a DB-23 to DB-9 cable that matches the pinouts of the DB-9 end
of your flickerFixer cable, the stock A1080 cable will not work. 

Switching with both the computer and the monitor powered up has caused
mot problems at all over the past year or so that I've been using the
switchbox. One suggestion, you might want to spend a little more on the
switchbox than I did. I've got an intermittent contact on the green
video pins of the switchbox that I've got to track down and fix. This
showed up after 6-9 months of use.
 
> 	An official answer from a CBM person would be best!

I surely don't qualify there, but it has worked just fine for me. And I
had a little fun with the switchbox label, it looks like:

	  __ Flicker
	 /
	O
	 \__ Fixer
-- 
Blaine Gardner @ Evans & Sutherland  580 Arapeen Drive, SLC, Utah 84108
Here:                                  There: (My Amiga running uucp)
blgardne@esunix.UUCP                   blaine@worsel.UUCP
{decwrl, utah-cs}!esunix!blgardne      utah-cs!caeco!i-core!worsel!blaine