[comp.sys.amiga.misc] Why?

c315-25@cs.UAlberta.CA (Huisman Kenneth M) (03/04/91)

I'm not sure if I should be posting this here or in .hardware, but anyways..

This is probably a question that has been asked many times by many different
people, but I would really like to know why PAL amigas have more scanlines
than NTSC amigas.  Why didn't they make them the same?  From a software
designer's point of view, wouldn't it have been easier to have the resolutions
be the same?  It is kind of a pain when you are playing games like 
Tobias's Startrek and you have to play in interlace mode with a scrunched up
screen.  Could someone please explain this to me?


Thanks.

Ken

c315-25@manning.cs.ualberta.ca

farren@sat.com (Michael J. Farren) (03/06/91)

c315-25@cs.UAlberta.CA writes:
>This is probably a question that has been asked many times by many different
>people, but I would really like to know why PAL amigas have more scanlines
>than NTSC amigas.

Because PAL screens have more scanlines than NTSC screens do.  PAL and NTSC
are television broadcast standards - in Europe, most color TV is PAL,
and in America (and Japan) most color TV is NTSC.  Just thank the ghods that
they didn't decide to also offer both SECAM modes :-)

>Why didn't they make them the same?

Well, if they did, then one of them wouldn't be standard.  There are many
reasons why adhering to a standard is better than not - the ease with which
Amigas can be used as broadcast video sources is one.

>From a software designer's point of view, wouldn't it have been easier
>to have the resolutions be the same?

Yes, but that is easily handled.  If the PAL designers wouldn't automatically
assume a 512-line screen, but would design their products to run in 400
lines, there'd be no problem at all.  (I only say that because it's a lot
easier to design for a smaller screen than you have than to design for a
bigger one - no way to get around that one!)
-- 
+-----------------------------------------------------------------------+
| Michael J. Farren                                      farren@sat.com |
|                        He's moody, but he's cute.                     |
+-----------------------------------------------------------------------+

fhwri%CONNCOLL.BITNET@yalevm.ycc.yale.edu (03/06/91)

PAL monitors have more scanlines than NTSC monitors because that's the way
that PAL (the European TV system) and NTSC (the US and Japan's TV system)
were set up. Naturally, you want a monitor that's compatible with your
TV service, as long as it accepts video input.

                                                --Rick Wrigley
                                                fhwri@conncoll.bitnet
                                ~~~second-hand smoke is THEFT~~~

patrick_meloy@outbound.wimsey.bc.ca (Patrick Meloy) (03/06/91)

>This is probably a question that has been asked many times by many different
>people, but I would really like to know why PAL amigas have more scanlines
>than NTSC amigas.  Why didn't they make them the same?  From a software
>designer's point of view, wouldn't it have been easier to have the
>resolutions
>be the same?  It is kind of a pain when you are playing games like 
>Tobias's Startrek and you have to play in interlace mode with a scrunched up
>screen.  Could someone please explain this to me?

The reason is VIDEO compatibility and international television standards.
North America chose to go with 60hz and a shorter screen, Europe chose 50hz
and a longer screen. They get a taller screen, but have you ever seen a PAL
screen? Even non-interlace screens have a flicker of sorts. 60hz is fast
enough that a non-interlace screen is refreshing faster than the eye can see,
50hz is just below that threshold and is quite visible. You DON'T WANT PAL!

---------------------------------------
| patrick_meloy@outbound.wimsey.bc.ca |
| 'The Outbound' BBS Vancouver BC     |
---------------------------------------

goddard@ste.dyn.bae.co.uk (Steve Goddard) (03/07/91)

In message <patrick_meloy.1043@outbound.wimsey.bc.ca>,
patrick_meloy@outbound.wimsey.bc.ca (Patrick Meloy) writes:
>The reason is VIDEO compatibility and international television standards.
>North America chose to go with 60hz and a shorter screen, Europe chose 50hz
>and a longer screen. They get a taller screen, but have you ever seen a PAL
>screen? Even non-interlace screens have a flicker of sorts. 60hz is fast
>enough that a non-interlace screen is refreshing faster than the eye can see,
>50hz is just below that threshold and is quite visible. You DON'T WANT PAL!

  IMHO, I would be inclined to disagree that 50Hz flicker is "quite visible".
While I have never seen a 60Hz video screen, and suspect that if an NTSC
and PAL screen were placed next to each other you would be able to see a
difference, I doubt very much it would be significant. Logically, not
even a _european_ :-) would design a TV system that had noticable flicker,
and if they did, europe would never get anything done, as most of the
population would be off sick with migraines after watching TV the previous
evening. In europe (well, my part at least) NTSC is a byword for how things
shouldn`t be done, as I am sure PAL is in the US. This is a religious issue,
and the truth lies somewhere between the two.
  Getting back to the Amiga, it is a little disturbing to see the NTSC
black bar at the bottom of the screen, as you get a feeling that the machine
is not being used to its fullest extent. Good software checks for the machine
type, and adjusts accordingly, but this is not always possible with pre-
drawn screens, etc. J. Toebes wrote a good article in Transactor some time
ago about international aspects of Amiga programs. It`s worth checking out.

Steve the G.  (Steve Goddard)
  "You can lead a hacker to a terminal, but you can't *make* him code"

wuethri@dgp.toronto.edu (Charles Wuethrich) (03/08/91)

In article <patrick_meloy.1043@outbound.wimsey.bc.ca> patrick_meloy@outbound.wimsey.bc.ca (Patrick Meloy) writes:
>
>The reason is VIDEO compatibility and international television standards.
>North America chose to go with 60hz and a shorter screen, Europe chose 50hz
>and a longer screen.

Another fact to be remembered is that in Europe the have 220 V, 50Hz
on the mains, while here you usually have 110, 60Hz.

I know, I know, 220/240 or 110/120. See ya

Charles

-- 
*    Charles Wuethrich, Dynamics Graphics Project, U. of Toronto   *
*                   wuethri@dgp.toronto.edu                        *

espie@flamingo.Stanford.EDU (Marc Espie) (03/09/91)

In article <1991Mar7.135528.10099@ste.dyn.bae.co.uk> goddard@ste.dyn.bae.co.uk (Steve Goddard) writes:
>In message <patrick_meloy.1043@outbound.wimsey.bc.ca>,
>patrick_meloy@outbound.wimsey.bc.ca (Patrick Meloy) writes:
>>The reason is VIDEO compatibility and international television standards.
>>North America chose to go with 60hz and a shorter screen, Europe chose 50hz
>>and a longer screen. They get a taller screen, but have you ever seen a PAL
>>screen? Even non-interlace screens have a flicker of sorts. 60hz is fast
>>enough that a non-interlace screen is refreshing faster than the eye can see,
>>50hz is just below that threshold and is quite visible. You DON'T WANT PAL!
                                        ----------------
This is not an objective statement.
>
>  IMHO, I would be inclined to disagree that 50Hz flicker is "quite visible".
>While I have never seen a 60Hz video screen, and suspect that if an NTSC
>and PAL screen were placed next to each other you would be able to see a
>difference, I doubt very much it would be significant. Logically, not
>even a _european_ :-) would design a TV system that had noticable flicker,
>and if they did, europe would never get anything done, as most of the
>population would be off sick with migraines after watching TV the previous
>evening. In europe (well, my part at least) NTSC is a byword for how things
>shouldn`t be done, as I am sure PAL is in the US. This is a religious issue,
>and the truth lies somewhere between the two.
>  Getting back to the Amiga, it is a little disturbing to see the NTSC
>black bar at the bottom of the screen, as you get a feeling that the machine
>is not being used to its fullest extent. Good software checks for the machine
>type, and adjusts accordingly, but this is not always possible with pre-
>drawn screens, etc. J. Toebes wrote a good article in Transactor some time
>ago about international aspects of Amiga programs. It`s worth checking out.
>
As a general rule, ``flicker'' depends on hardware AND on people.
People accustomed to 60Hz NTSC screen are quite dependable to notice
flicker on a 50Hz PAL screen, and accordingly label the stuff as junk.
On the other hand, color separation is atrocious on a NTSC system compared
to a PAL one, and european users don't fail to notice that.
I myself have been submitted to the following experiment: migrate from
Europe to the US, buy an amiga 3000 and use it for 6 months in NTSC
mode. Then one day, try and switch to PAL. Lo and behold ! flicker,
awfully noticeable. What is most interesting is that I had a PAL amiga
in Europe for more than 2 years and never noticed any flicker !!!
I'm sure if you were to do the reverse experiment, you would notice
PAL flicker gradually fade away over a short period. Aside of that, I'm
sure that people who work on 70Hz monitors notice flicker on these
baaaaad NTSC screens   :-)

Well, maybe PAL has side effects, like headaches if you work too long in
front of the same screen. In that case, I wouldn't assume NTSC to be free of
it.
--
	Marc Espie (espie@flamingo.stanford.edu)

dave@cs.arizona.edu (Dave P. Schaumann) (03/09/91)

Z
-- 
Dave Schaumann | dave@cs.arizona.edu | Short .sig's rule!

ludde@nada.kth.se (Erik Lundevall) (03/10/91)

In article <1991Mar8.210436.11753@neon.Stanford.EDU> espie@flamingo.Stanford.EDU (Marc Espie) writes:
>In article <1991Mar7.135528.10099@ste.dyn.bae.co.uk> goddard@ste.dyn.bae.co.uk (Steve Goddard) writes:
>>  IMHO, I would be inclined to disagree that 50Hz flicker is "quite visible".
>>While I have never seen a 60Hz video screen, and suspect that if an NTSC
[stuff deleted]
>As a general rule, ``flicker'' depends on hardware AND on people.
>People accustomed to 60Hz NTSC screen are quite dependable to notice
>flicker on a 50Hz PAL screen, and accordingly label the stuff as junk.
[stuff deleted]
>sure that people who work on 70Hz monitors notice flicker on these
>baaaaad NTSC screens   :-)

Many of the PAL-users who doesn't see any flicker probably have rather dark
background color. I find the 50Hz flickering quite visible, and switching to
60Hz is quite nice in that aspect.
The flickering in PAL mode is what I have found that a lot of 'professional
users' complain about here, and for good reason.
Having the possibility to switch to 60+ Hz is valuable. In Sweden the
recommended frequency for a screen with a light background is at least 70-80Hz
(dark backgrounds 50-60Hz). I guess there are similar recommendations in
other countries.

>--
>	Marc Espie (espie@flamingo.stanford.edu)


--
-Erik Lundevall  "Visitors are expected to complain at the reception between
                  9am and 11am daily."      -From a sign in a hotel in Aten
ludde@nada.kth.se | ludde@adder.bula.se | uunet!cbmvax!cbmehq!cbmswe!adder!ludde

eachus@aries.mitre.org (Robert I. Eachus) (03/12/91)

     Another problem is that the beat frequency between the lights
(especially fluorescent lights) and the screen can considerably
exaggerate the flicker.  I get bad headaches when using a Sun
Workstation with a 66 Hz refresh rate, but have much less trouble with
my (60 Hz) Amiga at home. (In the Amiga at work I have a flickerFixer
board...)  In either case, using a "warm" incandescent lamp is a big
improvement.  (Not due to the color of the light, but the warmer bulbs
reflect more light (and heat) back to the filament so that it cools
slower.  The perceived 120 Hz (or 100 Hz) flicker in an incandescent
lamp can be almost eliminated this way.)


--

					Robert I. Eachus

     "As far as Saddam Hussein being a great military strategist, he
is neither a strategist, nor is he schooled in the operational arts,
nor is he a tactician, nor is he a general, nor is he as a
soldier...

Other than that he's a great military man.  I want you to know that."
      -- Gen. H. Norman Schwarzkopf, Saudia Arabia, Feb. 27, 1991  

peterk@cbmger.UUCP (Peter Kittel GERMANY) (03/19/91)

In article <1991Mar8.210436.11753@neon.Stanford.EDU> espie@flamingo.Stanford.EDU (Marc Espie) writes:
>I myself have been submitted to the following experiment: migrate from
>Europe to the US, buy an amiga 3000 and use it for 6 months in NTSC
>mode. Then one day, try and switch to PAL. Lo and behold ! flicker,
>awfully noticeable.

But what you saw there is not the 50 Hz flicker, but the interference
of the 50 Hz screen and your 60 Hz room illumination or other devices
running at mains frequency. So you actually saw a 10 Hz flicker!

-- 
Best regards, Dr. Peter Kittel  // E-Mail to  \\  Only my personal opinions... 
Commodore Frankfurt, Germany  \X/ {uunet|pyramid|rutgers}!cbmvax!cbmger!peterk

David.Plummer@f70.n140.z1.FIDONET.ORG (David Plummer) (03/24/91)

 PK> espie@flamingo.Stanford.EDU (Marc Espie) writes: 
 PK> >I myself have been submitted to the following experiment: migrate 
 PK> from 
 PK> >Europe to the US, buy an amiga 3000 and use it for 6 months in NTSC 
 PK> >mode. Then one day, try and switch to PAL. Lo and behold ! flicker, 
 PK> >awfully noticeable. 
 PK>  
 PK> But what you saw there is not the 50 Hz flicker, but the interference 
 PK> of the 50 Hz screen and your 60 Hz room illumination or other devices 
 PK> running at mains frequency. So you actually saw a 10 Hz flicker! 
 PK>  
 PK> --  
 PK> Best regards, Dr. Peter Kittel  // E-Mail to  \\  Only my personal 
 PK> opinions...  
 PK> Commodore Frankfurt, Germany  \X/ 
 PK> {uunet|pyramid|rutgers}!cbmvax!cbmger!peterk 
 PK>  
 PK> --- ConfMail V3.31 
 PK>  * Origin: weyr.fidonet.org (1:140/22) 
 
But as I sit here looking at my NTSC Amiga running in PAL mode, 
contemplating why it flickers, I can't help but ask what rate does the 
sun flicker at?  Totally natural room lighting, PAL still flickers.
And this is on a 2080, so I can't help but wonder what it would look like
on a 1084.


--  
David Plummer - via FidoNet node 1:140/22
UUCP: ...!herald!weyr!70!David.Plummer
Domain: David.Plummer@f70.n140.z1.FIDONET.ORG
Standard Disclaimers Apply...