Path: chuka.playstation.co.uk!news
From: "Alex Herbert" <alex@herbs.dabsol.co.uk>
Newsgroups: scee.yaroze.beginners
Subject: Re: NTSC & PAL!?
Date: Mon, 27 Sep 1999 01:38:16 +0100
Organization: PlayStation Net Yaroze (SCEE)
Lines: 66
Message-ID: <7sme6p$7de1@chuka.playstation.co.uk>
References: <7sl3f1$2o91@chuka.playstation.co.uk>
NNTP-Posting-Host: 212.56.111.42
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 5.00.2314.1300
X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2314.1300


Scott Ward <scott.ward6@virgin.net> wrote in message
news:7sl3f1$2o91@chuka.playstation.co.uk...
> I think I'm in need of some basic tutoring in the ways of PAL and NTSC.
>
> Here's how I understand it:
>
> PAL - 50 fps. 256/512 horizontal lines.
> NTSC - 60 fps. 240/480 horizontal lines
>
> Until now I've always just left the Yaroze in it's default mode (which I
> thought was PAL but turned out to be NTSC). I didn't think there was any
> problem 'cos I had heard that in NTSC the picture was in black & white and
> mine was always in colour. Plus, I was always under the impression that
NTSC
> left a 'letterbox' effect because of the reduced horizontal lines and my
> picture has always been full screen. It's not until now that I've swapped
> the modes and PAL seems to squash the picture and leave the borders
> top/bottom of the screen.
>
> 1) Both modes show a clear picture in full colour on my TV. I've been told
> that some TV's swap modes automatically, is the case with my setup?
>

Most PAL TVs can sync to 60 fps, and if you're using an RGB Scart cable,
then you'll get full colour in NTSC.  It is rare for a PAL TV to be able to
decode NTSC colour info from a composite video signal.  The lead supplied
with the NY package is composite video only which is why so many of us
suffer from the B/W syndrome.

> 2) Why does PAL squash up and leave borders even when it has extra
> horizontal lines? It may make the resolution look better but it messes
with
> the vertical dimensions of the graphics. :o(
>
> 3)In the same way, why is NTSC full screen even though it has less
> horizontal lines? It may be more 'blocky' but at least the graphics look
> like they're supposed to.
>

NTSC should not have any top or bottom borders if the TV syncs ok.  The
scan-lines in NTSC are spaced further apart than in PAL.  240/480 lines is
enough to fill a NTSC screen.  PAL needs 288/576 lines to fill the picture -
hence the borders when running 256 lines.  The reason the graphics are
squashed is because the horizontal resolution hasn't been increased to
account for the extra virtical resolution.  The max horizontal resolution
for NTSC is 640 pixels, whereas PAL's max is 768.

> 4) This may seem obvious but in theory, does PAL leave you with slightly
> more cpu time?
>

Quite a bit more!  Although the GPU will have to do more work per frame as
there's more screen to draw to.

> Any help much appreciated.
>
> Cheers,
>
> Scott
>
>

Herbs