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Path: utzoo!watmath!clyde!rutgers!cbmvax!grr
From: grr@cbmvax.UUCP
Newsgroups: comp.sys.amiga
Subject: Re:  NTSCS standard
Message-ID: <1424@cbmvax.cbmvax.cbm.UUCP>
Date: Tue, 17-Feb-87 05:41:28 EST
Article-I.D.: cbmvax.1424
Posted: Tue Feb 17 05:41:28 1987
Date-Received: Wed, 18-Feb-87 04:01:27 EST
References: <1235@husc6.UUCP>
Reply-To: grr@cbmvax.UUCP (George Robbins)
Organization: Commodore Technology, West Chester, PA
Lines: 32

In article <1235@husc6.UUCP> grunau_b@husc4.UUCP (Justin J. M. Grunau) writes:
>
>But this confuses me - I understand that NTSC standards will not allow a 640 by
>400 non-interlaced display;  but I thought the Amiga was famous for having not
>only NTSC output, but also digital and analog RGB, which are, unless I am
>confused, NOT NTSC-compatible.  Could somebody enlighten me on the distinction?

While the RGB outputs are not really NTSC compatible, the sync format and timing
are relatively NTSC complient.  This makes possible simple encoding to NTSC
composite video and RF modulation, allowing the Amiga video output to be 
displayed on any normal color monitor or TV set.

If you do not have this degree of compatibility, then either the video encoding
becomes very complicate or the system must 'shift gears' between various
modes.  (Atari ST and various PC display cards...)

>Also -- one last piece of confusion:  I don't understand why the Amiga lacks
>normal TTL output for a high-resolution monochrome monitor;  I assume you can
>hook a mono monitor up to an Amiga if you choose;  what happens when you try to
>get high-resolution?

There's not much standard about TTL monitors - except perhaps in the PC World.
They run at 50Hz / 18KHz scan rates which is sort of compromise between the
phosphor characteristics, cheap monitor technology and video card design.

You can however, plug a cheap ($70-100) monochrome *composite* monitor into
the composite output of your amiga.  A long persistance phospher makes the
flicker go away, though you get a bit of smear while scrolling.
-- 
George Robbins - now working for,	uucp: {ihnp4|seismo|rutgers}!cbmvax!grr
but no way officially representing	arpa: cbmvax!grr@seismo.css.GOV
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)